Best printers for Home

Best Mixer Grinder

Best wired Earphones

Best 43 Inch TV in India

Best Wi Fi Routers

Best Home Theatre in India

Smart Watch under 5000

Best Laptops for Education

Best Laptop for Students

<ul class="summary-list"><li><a target="_blank" class="" href="https://www.businessinsider.com/comet-heading-earth-bright-outshine-stars-scientists-c-2023-a32023-3">Comet A3, or Comet Tsuchinshan-ATLAS</a>, is visible in the Northern Hemisphere this October.</li><li>The comet takes 80,000 years to orbit the sun, so Neanderthals were among the last people to see it.</li></ul><p>A rare comet is gleaming in our skies this October, it's your only chance to ever see it, and it might be <a target="_blank" class="" href="https://www.businessinsider.com/saw-northern-lights-surprising-photos-misleading-2024-5">visible to<strong> </strong>the naked eye</a>.</p><p>Comet Tsuchinshan-ATLAS, or Comet A3, is a dusty ball of ice from the Oort Cloud that takes about 80,000 years to orbit the sun. That means some of the last people to see it were <a target="_blank" class="" href="https://www.businessinsider.com/last-neanderthal-thorin-unique-dna-help-explain-species-extinction-2024-9">Neanderthals</a>.</p><p>This is the best opportunity in years, and possibly in a decade, to <a target="_blank" class="" href="https://www.businessinsider.com/green-comet-ztf-viewing-where-when-how-see-2023-1">see a bright comet in the sky</a>. Experts are hopeful that Comet A3 will be "highly memorable" and "a real crowd pleaser," according to Dan Bartlett, an astrophotographer who tracks comets.</p><p>But you <a target="_blank" class="" href="https://www.businessinsider.com/tried-see-green-comet-fail-2023-2">need to be prepared</a>.</p><p>"It's just hard to make the time to be in the right place, to have the right experience," Teddy Kareta, a <a target="_blank" class="" href="https://www.businessinsider.com/astronomer-animations-reveal-solar-system-physics-2021-10">planetary scientist</a> who specializes in comets at the Lowell Observatory, told Business Insider.</p><p>When Kareta has talked to people who have <a target="_blank" class="" href="https://www.businessinsider.com/devil-comet-visible-during-total-solar-eclipse-how-see-2024-4">seen a truly great comet</a>, though, "there's just nothing like it," he said.</p><p>Here's everything you should know to be in the right place at the right time and <a target="_blank" class="" href="https://www.businessinsider.com/how-when-to-see-green-comet-mars-together-night-sky-2023-2">spot the comet</a>.</p><h2 id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">How bright is Comet A3?</h2><p id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">Nobody is certain about how bright this comet will be, but Kareta says it has the potential to be the <a target="_blank" class="" href="https://www.businessinsider.com/how-to-see-green-comet-nishimura-2023-9">brightest comet</a> in a decade.</p><p id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">The last big, bold comet was <a target="_blank" class="" href="https://www.businessinsider.com/comet-neowise-surprise-appearance-earth-unprepared-for-asteroids-2020-7">NEOWISE in 2020</a>. It was visible to the naked eye and produced stunning photos like this:</p><div type="image" title="comet neowise belarus" height="1911" width="3000" msid="113849897" hostid="261" sizebytes="285386"></div><p id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">Astronomers are divided about whether Comet A3 will shine as <a target="_blank" class="" href="https://www.businessinsider.com/comet-neowise-passing-close-to-earth-dazzling-photos-videos-2020-7">bright as Comet NEOWISE</a>.</p><p id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">In recent weeks, A3 has at times been brighter than predicted and at other times matched predictions, according to the BBC's <a target="_blank" class="" href="https://www.skyatnightmagazine.com/space-science/beginners-guide-comet-c-2023-a3">Sky at Night Magazine</a> and Robert Massey, the deputy executive director of the <a target="_blank" class="" href="https://www.youtube.com/watch?v=w_mGtE7282Q&amp;ab_channel=RoyalAstronomicalSociety">Royal Astronomical Society</a>.</p><p id="11d1e1ae-eb70-4e43-aa3a-ab5cb2a93f24">From a dark-sky vantage point at Mono Lake, California — tucked into the Sierra Nevadas — Bartlett says he can see the comet with binoculars already.</p><p>But comets can change quickly, in a matter of hours. That's because their brightness depends on what type and amount of gas or dust they're emitting, and that can change on a dime.</p><p>For example, in 2007 Comet Holmes suddenly flared up and became 500,000 times brighter in just two days because a pocket of gas inside it had breached its surface, according to <a target="_blank" class="" href="https://www.space.com/20347-comet-brightness-predictions-difficult.html">Space.com</a>.</p><p>"Sometimes people will say that <a target="_blank" class="" href="https://www.businessinsider.com/comet-everest-sky-how-to-see-it-12p-pons-brooks-2024-3">predicting comets</a> is kind of like playing the lottery," Kareta said.</p><h2 id="f9be457b-ee58-4abd-b650-c3903d50bfb8">When and where to see Comet A3</h2><p id="f9be457b-ee58-4abd-b650-c3903d50bfb8">Weather permitting,<strong> </strong>everyone in the Northern Hemisphere should be able to see Comet A3 in October.</p><p id="f9be457b-ee58-4abd-b650-c3903d50bfb8">There are two windows to catch it, one from now through October 2 and another from October 12 to 30, according to a press release from Massey.</p><p id="f9be457b-ee58-4abd-b650-c3903d50bfb8">During the first window, the comet appears above the eastern horizon during a 15-minute window that begins one hour before sunrise, according to <a target="_blank" class="" href="https://www.space.com/comet-tsuchinshan-atlas-brightening-perihelion-how-to-see">Space.com</a>.</p><p id="f9be457b-ee58-4abd-b650-c3903d50bfb8">However, the best opportunity to see the comet, when it's <a target="_blank" class="" href="https://www.astronomy.com/observing/comet-tsuchinshan-atlas-may-soon-become-bright/">closest to Earth</a>, is during the second window. After sunset, it will shine in the west, just to the left of the Big Dipper's handle, making for a more schedule-friendly viewing time.</p><h2 id="f584376a-e5c8-4cf2-9b77-2d6434dabfc3">Where to go and what to bring</h2><p>For the best viewing, you should drive far from the city and gaze into a very dark sky. Check Business Insider's list of <a target="_blank" class="" href="https://www.businessinsider.com/darkest-skies-by-state-watch-space-events-stargazing">dark-sky spots in each state</a>.</p><div type="image" title="night sky with meteors shooting stars bright white streaks and one extra bright fireball above a rocky hillside of evergreen trees" height="681" width="1024" msid="113849895" hostid="261" sizebytes="82586"></div><p>If that's not an option, though, find a relatively dark spot outside the worst of the <a target="_blank" class="" href="https://www.businessinsider.com/what-dark-skies-look-like-how-many-more-stars-than-cities-suburbs">city lights</a> — maybe on a hill or just outside the city — where you can face away from any major light sources to look toward Comet A3.</p><p>"Even if you live in an area with lots and lots of street lights, lots of smog, lots of smoke, lots of whatever, you still ought to go for it," Kareta said.</p><p>Check the weather before you go. If it will be cloudy all night, for example, you may want to plan for another evening. Bring warm layers and a chair or blanket to lay back on. Without support, you might be surprised how quickly your neck gets tired of craning back to <a target="_blank" class="" href="https://www.businessinsider.com/how-to-see-exploding-star-nova-nasa-says-expect-soon-2024-3">look at the stars</a>.</p><p>If you have binoculars or a telescope, bring them. There's no guarantee of naked-eye visibility. In some cities, you can check out binoculars or a telescope from your local library.</p><p>Especially if you're a beginner, you may want to download a skywatching app like Sky Safari ($4.99 in the App Store) or pull up a website like Stellarium (free) on your phone. Once you're on the ground, that will help you pinpoint where the comet is in the sky.</p><h2 id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">How to look for the comet</h2><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">Finding a comet in the sky is harder than you might think. You'll need to know a few tips and techniques.</p><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">Once you reach your comet-watching spot, it can help to open your skywatching app to identify exactly where the comet is in the sky, near a constellation you recognize — like the Big Dipper.</p><p>Then give your eyes at least 30 minutes to adjust to the dark. Try not to look at your phone. Even a small burst of blue light is enough to reset your eyes.</p><p>If the comet doesn't immediately jump out to you, try scanning around the area. Your peripheral vision is more sensitive to faint objects, so you might spot it in the corner of your eye.</p><p><a target="_blank" class="" href="https://www.businessinsider.com/green-comet-ztf-what-look-like-see-photos-2023-1">You're looking for</a> a smudge, slightly bigger than a star. It won't twinkle like the stars do, and it will look a bit blurrier, with less defined borders. It might appear elongated because of the comet's tail, which is dust and gas flowing off its icy body.</p><p>"If you look at it and it looks like it's behaving differently than some of the stars nearby, that's a really good sign that you've picked up on the right thing," Kareta said.</p><p>If you're still not sure, try taking a long-exposure photo with your phone. This is built into most phone cameras' nighttime settings. (Hint: Turn your brightness down to protect your eyes.)</p><p>The long exposure will provide a clearer image of the comet than your eyes can.</p><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">If you can't find Comet A3 at all, Kareta recommends trying again a few days later.</p><p>"Go one night out, and then take a night off, and go back out. You'll know better how to time it, how to get ready," he said.</p><h2 id="4dc3ee16-f7a1-4a12-9138-5ef798a3a762">How to photograph the comet</h2><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">If your phone isn't picking up the comet, a DSLR camera might do the trick. Massey recommends taking a series of exposures.</p><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">You can also hold your phone camera up to the lens of your binoculars or telescope to take a picture through it. That method can be tricky, so it helps to practice a bit in advance.</p><p id="b4523206-0dfd-4a5e-acaf-d6a8ee9de2a4">After this, Comet A3 won't return for tens of thousands of years. "See it now or lose your chance," Kareta said.</p>

How to see Comet A3, which could be the best comet in a decade. Neanderthals walked the Earth last time it flew by.

<ul><li><keyword id="9531572" type="UNKNOWN" weightage="20" keywordseo="comet-neowise">Comet Neowise</keyword> will the first comet to burn bright over Earth’s skies after <keyword id="9066921" type="UNKNOWN" weightage="20" keywordseo="comet-atlas">Comet Atlas</keyword> and Swan fizzled out earlier this year. <br /></li><li>It will be visible over India for the next 20 days getting brighter each evening.<br /></li><li>Scientists at the Planetary Science Institute (PSI) are already watching the comet and observe that it has a rare sodium tail than burns the same colour as street lamps.<br /></li></ul>Comet Neowise will be visible in India’s skies for the next 20 days as it approaches the Sun for the first time in 4,500 years. It’s the third comet that astronomers were hoping would grace Earth’s skies, and the first one to live up to its promise. <br /><br />"From July 14, C/2020 F3, a comet discovered on March 27, will be clearly visible in the north-western sky. It will be visible after sunset for around 20 minutes for the next 20 days. People can observe it from naked eyes," Subhendu Pattnaik, deputy director of Pathani Samanta Planetarium in Bhubaneswar told the <a href="https://www.orissapost.com/comet-neowise-to-be-visible-in-odisha-skies-from-july-14/">OrissaPOST</a>.<br /><br />The previous two comets, Atlas and Swan, fizzled out before they could become bright enough to be seen by the naked eye. Atlas crumbed to pieces before reaching Earth and Swan was made up of gas, resulting in a much dimmer view than expected.<br /><br />Comet Neowise, on the other hand, will be burning in a blaze of glory in the skies above India — getting brighter each day — before it disappears for another 6,800 years.<br /><br /><strong>They’ve already caught its tail<br /></strong>Scientists at the Planetary Science Institute (PSI) are already watching the comet with a hawk-eye. According to them, Neowise has a sodium tail — something that’s only been observed in very bright comets, such as Hale-Bopp and the sungrazer ISON<br /><br /><div type="image" title="fp_Neowise_Carl" msid="76953333" hostid="261" caption="&amp;lt;p&amp;gt;Left: light reflected off of cometary dust, which generally follows the appearance to the naked eye. Right: light emitted by sodium atoms.&amp;lt;/p&amp;gt;"></div><br />Unlike the <keyword id="9571123" type="UNKNOWN" weightage="20" keywordseo="comet-tail">comet tail</keyword> that we see down on Earth, Neowise’s sodium tail is narrower, longer and points directly away from the Sun making it very difficult to catch on camera.<br /><br />"Atomic sodium responds to sunlight in a similar way to cometary dust, but its momentum kick comes from a very particular wavelength of yellow light – the same colour seen in sodium vapour street lamps," said Planetary Science Institute Senior Scientist <a href="https://psi.edu/news/neowisesodiumtail">Jeffrey Morgenthaler</a>.<br /><br />Comets are essentially icy dirtballs. Their tails are made up of dust, gas and plasma — ionised gas. As they approach the sun, the heat from the sunlight causes the ice to turn into gas. As the gas escapes, it drags ‘material’ — what we Earthlings refer to as dust — with it. <br /><br />As sunlight reflects off the dust, the momentum causes it to drift away from the Sun. However, some of the bigger pieces don’t just float away. The heavier bits stick around and form the tail of the comet. As the light gets re-emitted in a random direction, we catch the view of the comet’s tail down on Earth. <br /><br /><strong>SEE ALSO:<br /><a href="https://www.businessinsider.in/science/news/3-missions-to-mars-launch-this-month-from-nasa-china-and-the-united-arab-emirates-heres-what-theyll-do-on-the-red-planet/articleshow/76949688.cms">3 missions to Mars launch this month, from NASA, China, and the United Arab Emirates — here's what they'll do on the red planet</a><br /><br /><a href="https://www.businessinsider.in/science/space/news/nasa-new-rules-to-protect-mars-and-moon-from-earth-germs/articleshow/76906055.cms">NASA issues new guidelines to protect the Moon and Mars from Earth's germs</a><br /><br /></strong><a href="https://www.businessinsider.in/science/space/news/nasas-latest-pictures-from-mars-are-fascinating-showing-where-the-curiosity-rover-is-headed-next/articleshow/76825564.cms"><strong>NASA's latest pictures from Mars are fascinating — showing where the Curiosity rover is headed next</strong></a><br />

Comet Neowise will burn bright over India for the next 20 days after two earlier comets fizzled out

IN PICS: Comet NEOWISE spotted blazing from the Stonehenge to the Swiss Alps, in skies all over the world

<ul class="summary-list"><li><keyword id="9531572" type="UNKNOWN" weightage="60" keywordseo="comet-neowise">Comet Neowise</keyword> has dazzled stargazers this week, but its surprise appearance highlights one of Earth's greatest vulnerabilities.</li><li><keyword id="6360409" type="UNKNOWN" weightage="60" keywordseo="Nasa">NASA</keyword> discovered the comet hurtling towards Earth three months ago, but only because one of its space <keyword id="62018" type="PERSON" weightage="60" keywordseo="Telescopes">telescopes</keyword> got lucky.</li><li>Our planet is woefully unprepared for the enormous, deadly rocks that hurtle towards us from deep space. But a telescope NASA is developing could track more dangerous <keyword id="81841" type="PERSON" weightage="60" keywordseo="Asteroids">asteroids</keyword>.</li></ul><p>A welcome distraction has turned the world's eyes to the sky this week. Comet Neowise, a 3-mile-wide chunk of space ice, is rocketing past our planet, creating a spectacle in the night: a brilliant ball of white light with long, colorful tails.</p><p>The comet is a benign and beautiful sight, but it highlights a global vulnerability. Tens of thousands of potentially dangerous objects regularly careen past Earth undetected, and some of them inevitably crash into it.</p><p><keyword id="51550" type="PERSON" weightage="60" keywordseo="comets">Comets</keyword> — balls of space ice and dust — almost never pose a threat to Earth, but asteroids and meteors (smaller chunks of rock) come close more often. Although impacts are extremely rare, a space rock big enough to destroy a city (or worse) could hurtle towards Earth at any time, and scientists might not see it until it's far too late.</p><p>Nobody even knew Comet Neowise existed until a NASA space telescope discovered it approaching just three months ago. The spacecraft was scanning for asteroids and comets (balls of space ice and dust) that fly too close to Earth. The mission is called the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) — that's where the new comet gets its name.</p><p><div type="image" title="comet neowise belarus" height="1918" width="2557" msid="77038711" hostid="261"></div></p><p>"This is an example of an object coming out of deep space that our survey capabilities need to be able to spot," Lindley Johnson, a <keyword id="2812558" type="PERSON" weightage="60" keywordseo="planetary-defense">planetary defense</keyword> officer at NASA, said in a press briefing about Comet Neowise on Wednesday. "In this case, we were lucky that it did cross the field of view of the NEOWISE spacecraft back in March."</p><p>Many "<keyword id="1821718" type="PERSON" weightage="60" keywordseo="near-Earth-objects">near-Earth objects</keyword>" (NEOs) do not cross any telescope's line of sight, and several potentially dangerous asteroids have snuck up on Earth in recent years.</p><p>"Luck is not a plan," Richard Binzel, an asteroid researcher and professor of planetary sciences at MIT, <a href="https://www.businessinsider.com/nasa-space-telescope-to-detect-deadly-asteroids-2019-9">told Business Insider</a> in September.</p><h2>Dangerous asteroids can fly under the radar</h2><p><div type="image" title="Chicxulub_impact asteroid" height="2089" width="2785" msid="77038716" hostid="261"></div></p><p>A 6-mile-wide asteroid surprised the dinosaurs 65 million years ago when it crashed into Earth. The impact caused a mile-high tsunami, sparked wildfires, and released billions of tons of sulfur into the atmosphere, blotting out the sun for years. That was the end of the age of big lizards.</p><p>In case scientists discover such an asteroid approaching Earth again, NASA has considered some ways to push it off its collision course: slamming a spacecraft into it, detonating an explosion near it, or firing lasers that heat and vaporize the rock enough to change its orbit.</p><p>But that takes time and the technology is unproven. What if nobody spots the asteroid until it's too late?</p><p>In recent years, scientists have missed plenty of large, dangerous objects approaching Earth.</p><p>"We feel we've only found about a third of the population of asteroids that are out there that could represent an impact hazard to the Earth," Johnson said.</p><p>In 2013, a meteor measuring about 65 feet in diameter and traveling at 40,000 mph entered the atmosphere and exploded over Chelyabinsk in central Russia. The blast sent out a shock wave that broke windows and damaged buildings across the region, injuring more than 1,400 people.</p><p><a href="https://www.businessinsider.com/nasa-threat-of-meteor-crashing-into-earth-is-bigger-than-you-think-2019-5">According to NASA modeling</a>, an event like the Chelyabinsk meteor occurs about every 60 years. That same day, a larger asteroid came within 17,000 miles of Earth.</p><p><div type="image" title="asteroid russia Chelyabinsk" height="3744" width="5616" msid="77038726" hostid="261"></div></p><p>Then a year ago a 427-foot-wide, "city-killer" asteroid <a href="https://www.businessinsider.com/asteroid-flies-close-to-earth-surprising-scientists-2019-7">flew within 45,000 miles of Earth</a>. NASA had almost no warning about it.</p><p>That's because right now, the only way scientists can track an NEO is by pointing a telescope toward the right place at the right time. Telescopes detect the sunlight that asteroids reflect, but the smaller the asteroid, the fainter the reflection. Plus, some asteroids just aren't very reflective.</p><p><div type="image" title="NEOWISE" height="1024" width="1365" msid="77038734" hostid="261"></div></p><p>NEOWISE (the NASA mission, not the comet) is not enough to protect us on its own, and it is living on borrowed time. Hunting asteroids is its second career, which came after it outlived its first mission: scanning the entire sky twice in infrared light. That initial project yielded copious data on distant stars and galaxies.</p><p>"This is a telescope that is well past its expiration date and, like a very old car, every day is a gift," Amy Mainzer, the telescope's principal investigator, said. "We're not really sure how much longer it's going to go. In theory, maybe another year at most."</p><p>When NEOWISE goes dark, it will leave Earth even more oblivious to threats from space.</p><h2>NASA is planning its first planetary defense spacecraft</h2><p><div type="image" title="neocam asteroid hunter spacecraft discovery nasa jpl caltech" height="1476" width="1968" msid="77038739" hostid="261"></div></p><p>A plan for better NEO surveillance finally gained some traction in September, when NASA announced plans for a new asteroid-hunting space telescope. The project is still in its early stages, though.</p><p>Called the Near-Earth Object Surveillance Mission (NEOSM), the spacecraft would feature heat-sensing infrared sensors capable of detecting even dark asteroids, which are the most difficult to find. (Because the sun warms up space rocks, they emit infrared light even if they don't reflect much visible light.)</p><p>Unlike NEOWISE, NEOSM would be dedicated to tracking objects near Earth. It would also fix a major blind spot: It could pick up on objects coming from the direction of the sun, where most telescopes can't look.</p><p>"This is the first time NASA has ever voiced a commitment to flying a space-based asteroid survey," Binzel said of the mission. "They've always said 'we'll study it, we'll study it,' and now they say 'we are going to do it.'"</p><p>The agency's 2020 budget allotted nearly $36 million for the telescope's development. If funding continues, it could launch as early as 2025.</p><p>"Having knowledge of what's out there is something that the planetary <keyword id="41551" type="ENTERTAINMENT" weightage="100" keywordseo="science">science</keyword> community has been advocating for for nearly 30 years," Binzel said. "This is a breakthrough decades in the making."</p>

Comet Neowise is a dazzling sight, but it's also a reminder of how woefully unprepared we are for dangerous asteroids

<ul class="summary-list"><li>A spectacular photo shows <a href="https://www.businessinsider.com/how-to-see-comet-neowise-when-where-to-look-2020-7">Comet Neowise</a> hanging amid the <keyword id="270371" type="PERSON" weightage="60" keywordseo="Aurora-Borealis">aurora borealis</keyword>, with a mysterious atmospheric phenomenon called <keyword id="26233" type="PERSON" weightage="60" keywordseo="steve">STEVE</keyword> and a <keyword id="1565035" type="PERSON" weightage="60" keywordseo="meteor">meteor</keyword> streaking overhead.</li><li>Farmer Donna Lach snapped the action-packed shot on Tuesday while she was photographing the comet.</li><li>After August, <keyword id="9531572" type="UNKNOWN" weightage="60" keywordseo="comet-neowise">Comet Neowise</keyword> won't be visible on Earth again for another 6,800 years. </li></ul><p>Comet Neowise — a glowing ball of <keyword id="41531" type="COMPANY" weightage="60" keywordseo="space">space</keyword> ice with two colorful tails — has starred in countless photos as it streaks through the skies across the Northern Hemisphere this week. On Tuesday, three cosmic co-stars joined it, making for an astonishing spectacle.</p><p>The image above shows a split-second meteor streaking across the sky, the green <keyword id="337466" type="ENTERTAINMENT" weightage="60" keywordseo="Aurora">aurora</keyword> shimmering over Comet Neowise, and purple ribbons dancing in a mysterious atmospheric phenomenon called <a href="https://www.businessinsider.com/new-aurora-found-by-amateur-astronomers-farther-south-2018-3">Strong Thermal Emissions Velocity Enhancement (STEVE)</a>.</p><p>The shot was one of nearly 600 that photographer and farmer <a href="https://twitter.com/lachdonna?lang=en">Donna Lach</a> snapped on Tuesday night near her farm in Manitoba, Canada. Lach volunteers for a citizen <keyword id="41551" type="ENTERTAINMENT" weightage="100" keywordseo="science">science</keyword> project called Aurorasaurus, funded by NASA and the National Science Foundation, which first discovered STEVE in 2016.</p><p><div type="image" title="steve neowise comet meteor aurora skitch 2" height="1600" width="2400" msid="77028467" hostid="261"></div></p><p>The aurora appears when charged particles from the sun interact with oxygen and nitrogen in Earth's atmosphere, but STEVE's origins are still a mystery.</p><p>From Lach's vantage point, both sets of colorful lights lined up perfectly with the fleeting appearance of a meteor — a space rock vaporizing in Earth's atmosphere — all while Comet Neowise hung bright near the horizon.</p><p>The comet is expected to get closest to our planet on July 23, approaching within about 64 million miles. But the next few nights — through Sunday — may provide the best opportunity to spot it in the sky. After it rockets away again, Neowise won't return to the inner solar system for 6,768 years.</p><p>Lach said she initially set out to capture the comet against the aurora borealis.</p><p>"The reports had been forecasting aurora for a couple of days so I was going to be ready to catch both," she told Business Insider. She wasn't expecting STEVE or the meteor.</p><p>She applied "a good layer of DEET," she said,  and then "stood there swatting mosquitoes forever until it finally got dark."</p><p>By 11:30 p.m., the comet was high above the horizon and the aurora was glittering across half the sky. An hour and a half later, the vertical stripes of STEVE appeared — far from the comet, but not too far for her camera's wide-angle lens. </p><p>"I was thrilled to see I could catch the span from STEVE to Neowise," Lach said. "I couldn't believe it when I caught the long meteor in one frame. I just stood smiling and saying 'wow' to myself and the critters in the ditch."</p><p>Lach added that the glittering display gave her "an epic night that I will never forget."</p>

Comet Neowise, a meteor, and a mysterious aurora-like phenomenon called STEVE all share the night sky in one incredible photo

<ul class="summary-list"><li><a href="https://www.businessinsider.com/comet-neowise-passing-close-to-earth-dazzling-photos-videos-2020-7">Comet Neowise</a> is <a href="https://www.businessinsider.com/comet-neowise-rising-above-earth-astronaut-2020-7">streaking past Earth</a> with two brightly colored tails of gas and dust.</li><li>This week is prime viewing time. After the comet rockets back to the outer solar system, it won't be visible from Earth for another 6,800 years.</li><li>Here's how to spot the brilliant flare as it rises above the horizon.</li></ul><p>This month offers your only chance to see a 3-mile-wide comet called Neowise as it rockets past Earth. The ball of <keyword id="41531" type="COMPANY" weightage="60" keywordseo="space">space</keyword> ice and its brightly colored tails are expected to reach peak brightness this week.</p><p>Neowise came from the outermost reaches of our solar system. Its orbit took it dangerously close to the sun on July 3 — 10 million miles closer than Mercury's orbit — but Neowise survived and made its way toward Earth. Now it's visible to the naked eye throughout the Northern Hemisphere.</p><p>The comet is expected to get closest to our planet on July 23, approaching within about 64 million miles, according to NASA. But this week, from now through Sunday, may provide the best opportunity to spot it in the sky.</p><p>Then it will rocket away again, toward the edges of the sun's reach. It won't return to the inner solar system for 6,768 years.</p><h2>How to spot Neowise</h2><p><div type="image" title="comet Neowise landscape mount mt shasta oregon copyright jesse smith sm" height="1331" width="2000" msid="76984669" hostid="261"></div></p><p>So far, many comet viewers have had to stay up all night or wake up before dawn to see Neowise rise above the horizon. But <a href="https://www.space.com/comet-neowise-visibility-july-2020.html" target="_blank" rel="noopener">according to Space.com</a>, the comet's "prime-time" viewing hours will come in the evenings this week, about 80 minutes after sunset.</p><p>To catch the ball of space ice and its split tails of white dust and blue ionized gas, look close to the horizon.</p><p>If you're an early riser, Neowise should also appear before sunrise, about 10 degrees above the northeast horizon — that's about the width of your clenched fist if you hold it at arm's length. It will drop over the next few days, to about 5 degrees by Saturday. After that, it will be too low to see in the mornings.</p><p><div type="image" title="comet neowise st marks tower malta" height="1532" width="2043" msid="76984675" hostid="261"></div></p><p>After sunset, however, the comet will be higher in the sky and easier to see as the week progresses. By Sunday, it will hang 20 degrees (two fists) above the horizon. Neowise rises in the northwest in the evenings.</p><p>You won't need a telescope or binoculars — Neowise is visible to the naked eye in dark skies. It's easiest to see if you're far from bright city lights.</p>

Comet Neowise is easily visible in the night sky this week. Here's when and where to look for it.

<ul class="summary-list"><li>Astronomers have spotted a newly-referenced comet that is heading towards Earth. </li><li>The comet is likely to be so bright it could outshine our stars. </li></ul><p>A recently-spotted comet is expected to shine brighter than the stars in the night sky as it passes our planet, according to astronomers.</p><p><a href="https://minorplanetcenter.net/mpec/K23/K23D77.html" target="_blank" rel="noopener">The comet, named C/2023 A3,</a> is hurtling toward the Earth at about 180,610 mph, per space.com. </p><p>If all goes well, the comet, which last passed by the Earth about 80,000 years ago, will start being visible with the naked eye around October 2024, <a href="https://minorplanetcenter.net/mpec/K23/K23D77.html" target="_blank" rel="noopener">according to data from the Minor Planet Center.</a></p><p>It could be as bright or brighter as our stars, and much more brilliant than the recent <a href="https://www.businessinsider.com/green-comet-ztf-what-look-like-see-photos-2023-1">ZTF green comet</a> that passed the Earth last month. </p><h2>Brighter than the Green Comet</h2><p>C/2023 A3 is expected to reach a brightness magnitude between -0.7 and -5, per space.com. That technical term means it will potentially be <a href="https://www.businessinsider.com/how-to-see-venus-during-daytime-2013-12">as bright as Venus</a> in our night skies.</p><p>By comparison, the <a href="https://www.businessinsider.com/what-is-the-green-comet-science-explains-its-glow-2023-1?r=US&amp;IR=T">recent Green Comet ZTF</a> had a brightness of around magnitude +4.6 (the lower the magnitude, the brighter), per space.com.</p><div type="image" title="Comet ZTF is shown against the night sky." height="1500" width="2000" msid="98478948" hostid="261" sizebytes="266958"></div><p>That means C/2023 A3 has the potential to be at least about 100 times brighter than ZTF, and six times brighter than <a href="https://www.businessinsider.com/comet-neowise-passing-close-to-earth-dazzling-photos-videos-2020-7">NEOWISE</a>, a comet that grazed the Earth in 2020, according to Ukrainian astronomy magazine The Universe. Space. Tech. </p><p>But of course, these are just predictions, and a lot could happen to the comet before then.</p><p>For one, the comet will have to survive the sun. The ball of gas, ice, and dust is now heading toward our star and it will have to survive its smoldering rays. The critical moment will be its perihelion — its closest approach to the sun — on September 24, 2024. </p><p>Still, scientists are hopeful, according to <a href="https://universemagazine.com/en/main-comet-of-2024-gets-the-name/" target="_blank" rel="noopener">the Universe. Space. Tech.</a>, because the comet is expected to be quite large and its perihelion is far from the sun, about 36 million miles away. </p><h2>NASA keeps a close eye out for objects that graze the Earth</h2><p>C/2023 A3 was spotted on February 22 by the NASA-funded asteroid early detection system Asteroid Terrestrial-impact Last Alert System (ATLAS).</p><p>The system, operated by the University of Hawaii, is made up of four telescopes placed in Hawaii, Chile, and South Africa. These automatically scan the sky to spot potential threats to Earth coming from the sky. </p><p>NASA keeps a close eye on near-Earth objects that could <a href="https://www.businessinsider.com/planet-killer-asteroid-could-threaten-earth-in-a-few-millennia-2022-10?r=US&amp;IR=T">hurt our planet,</a> but it doesn't always catch them this early.</p><p>For instance, NEOWISE was <a href="https://www.businessinsider.com/comet-neowise-surprise-appearance-earth-unprepared-for-asteroids-2020-7">spotted only three months before</a> it passed by the Earth in 2020. On that occasion, we were lucky and the comet only passed our planet, offering spectacular vistas to onlookers. </p><p>C/2023 A3, however, isn't expected to be a planetary threat. Astronomers think it will pass about 0.5 Astronomical Units, or 44 million miles, from our planet. </p>

A bright comet is heading towards Earth and could outshine the stars in the sky, say astronomers

<ul class="summary-list"><li><keyword id="41531" type="COMPANY" weightage="60" keywordseo="space">Space</keyword> agencies around the world took part in a <keyword id="6360409" type="UNKNOWN" weightage="60" keywordseo="Nasa">NASA</keyword> <keyword id="67741" type="TECHNOLOGY" weightage="60" keywordseo="Simulation">simulation</keyword> of an asteroid-impact scenario.</li><li>The participating experts learned about a fictitious <keyword id="6549794" type="UNKNOWN" weightage="60" keywordseo="asteroid">asteroid</keyword>'s trajectory and had to react.</li><li>In the exercise, they couldn't stop it from hitting Europe, showing how <a href="https://www.businessinsider.com/comet-neowise-surprise-appearance-earth-unprepared-for-asteroids-2020-7">unprepared we are for such a crisis</a>.</li></ul><p>Scientists around the world have been bamboozled this week by a fictitious asteroid heading toward Earth.</p><p>A group of experts from US and European space agencies attended a week-long exercise led by NASA in which they faced a hypothetical scenario: An asteroid 35 million miles away was approaching the planet and could hit within six months.</p><p>With each passing day of the exercise, the participants learned more about the asteroid's size, trajectory, and chance of impact. Then they had to cooperate and use their technological knowledge to see if anything could be done to stop the space rock.</p><p>The experts fell short. The group determined that none of Earth's existing technologies could stop the hypothetical asteroid from striking given the six-month timeframe of the simulation. In this alternate reality, the asteroid crashed into eastern Europe.</p><p>As far as we know, no asteroids currently pose a threat to Earth in this way. But an estimated two-thirds of asteroids 460 feet in size or bigger - large enough to wreak considerable havoc - <a href="https://www.nasa.gov/planetarydefense/faq/">remain undiscovered</a>. That's why NASA and other agencies are attempting to prepare for such a situation. </p><p>"These exercises ultimately help the planetary-defense community communicate with each other and with our governments to ensure we are all coordinated should a potential impact threat be identified in the future," Lindley Johnson, NASA's planetary defense officer, <a href="https://www.jpl.nasa.gov/news/nasa-to-participate-in-tabletop-exercise-simulating-asteroid-impact">said in a press release</a>. </p><h2>6 months is not enough time to prepare for an asteroid impact</h2><p>The fictitious asteroid in the simulation was called 2021PDC. In NASA's scenario, it was first "spotted" on April 19, at which time it was thought to have a 5% of hitting our planet on October 20, six months after its discovery date. </p><p>But Day 2 of the exercise fast-forwarded to May 2, when new impact-trajectory calculations showed that 2021PDC would almost certainly hit either Europe or northern Africa. The participants in the simulation considered various missions in which spacecraft could try to destroy the asteroid or deflect it off its path.</p><div type="image" title="hypothetical impact" height="915" width="1120" msid="82344056" hostid="261"></div><p>But they concluded that such missions wouldn't be able to get off the ground in the short amount of time before the asteroid's impact.</p><p>"If confronted with the 2021PDC hypothetical scenario in real life, we would not be able us to launch any spacecraft on such short notice with current capabilities," <a href="https://cneos.jpl.nasa.gov/pd/cs/pdc21/pdc21_day2_briefing2.pdf">the participants said</a>. </p><p>They also considered trying to blow up or disrupt the asteroid using a nuclear explosive device.</p><p>"Deploying a nuclear disruption mission could significantly reduce the risk of impact damage," they found.</p><p>Still, the simulation stipulated that 2021PDC could be anywhere from 114 feet to half a mile in size, so the chance that a nuke could make a dent was uncertain. </p><p>Day 3 of the exercise skipped ahead to June 30, and Earth's future looked grim: 2021PDC's impact trajectory showed it headed for eastern Europe. By Day 4, which fast-forwarded to a week before the asteroid impact, there was a 99% chance the asteroid would hit near the border between Germany, the Czech Republic, and Austria. The explosion would bring as much energy as a large nuclear bomb.</p><p>All that could be done was evacuate the affected regions ahead of time.</p><h2>Most asteroids fly under the radar, and many are spotted too late</h2><div type="image" title="dinosaur asteroid meteor" height="1017" width="1440" msid="82344057" hostid="261"></div><p>It's tempting to assume that in the real world, astronomers would spot an asteroid akin to 2021PDC with much more notice than six months. But the world's ability to surveil near-Earth objects (NEOs) is woefully incomplete.</p><p>Any space rock with an orbit that takes it within 125 million miles of the sun is considered an NEO. But Johnson said in July that NASA thinks "we've only found about a third of the population of asteroids that are out there that could represent an impact hazard to the Earth."</p><p>Of course, humanity hopes to avoid a surprise like the dinosaurs got 65 million years ago, when a 6-mile-wide asteroid crashed into the Earth. But in recent years, scientists have missed plenty of large, dangerous objects that came close.</p><div type="image" title="comet neowise japan" height="1406" width="2500" msid="82344060" hostid="261"></div><p>Comet Neowise, a 3-mile-wide chunk of space ice, <a href="https://www.businessinsider.com/comet-neowise-surprise-appearance-earth-unprepared-for-asteroids-2020-7">passed with 64 million miles of Earth</a> in July. Nobody knew that comet existed until a NASA space telescope discovered it approaching four months prior.</p><p>In 2013, a meteor about 65 feet in diameter entered the atmosphere traveling 40,000 mph. It exploded over Chelyabinsk, Russia, without warning, sending out a shock wave that broke windows and damaged buildings across the region. More than 1,400 people were injured.</p><div type="image" title="asteroid russia Chelyabinsk" height="3744" width="5616" msid="82344061" hostid="261"></div><p>And in 2019, a 427-foot-wide, "city-killer" asteroid <a href="https://www.businessinsider.com/asteroid-flies-close-to-earth-surprising-scientists-2019-7">flew within 45,000 miles of Earth</a>. NASA had almost no warning about it.</p><p>That's because currently, the only way scientists can track an NEO is by pointing one of Earth's limited number of powerful telescopes in the right direction at the right time. </p><p>To address that problem, NASA announced two years ago that it would launch a new space telescope dedicated to watching for hazardous asteroids. That telescope, named the Near-Earth Object Surveillance Mission, along with the European Space Agency's newly launched <a href="https://www.esa.int/Safety_Security/Planetary_Defence/New_ESA_telescope_in_South_America_to_search_for_asteroids" target="_blank" rel="noopener noreferrer">Test-Bed Telescope</a> and the <a href="https://www.esa.int/ESA_Multimedia/Images/2017/02/Flyeye_Observatory" target="_blank" rel="noopener noreferrer">Flyeye Telescope</a> that's being built in Italy, should eventually bolster the number of NEOs we can track.</p><h2>NASA is testing ways to stymie an asteroid</h2><div type="image" title="DART nasa asteroid mission spacecraft" height="1406" width="2500" msid="82344065" hostid="261"></div><p>NASA has investigated the options scientists would have if they were to find a dangerous asteroid on a collision course with Earth. These include detonating an explosive device near the space rock, as the exercise participants suggested, or firing lasers that could heat up and vaporize the asteroid enough to change its path.</p><p>Another possibility is sending a spacecraft up to slam into an oncoming asteroid, thereby knocking it off its trajectory. This is the strategy NASA is most serious about: Later this year, the agency is scheduled to launch a test of such a technology. The Double Asteroid Redirection Test (<keyword id="348209" type="PERSON" weightage="60" keywordseo="Dart">DART</keyword>) will send a spacecraft to the asteroid Dimorphos and purposefully hit it in the fall of 2022.</p><p>NASA hopes that collision will change Dimorphos's orbit. While that asteroid isn't a threat to Earth, the mission could prove that redirecting an asteroid is possible with enough lead time.</p>

In a NASA simulation of an asteroid impact, scientists concluded they couldn't stop a space rock from decimating Europe

<ul><li>The COSMA supercomputer was used to create 3D simulations of what would happen to a planet’s atmosphere due to giant impacts. <br /></li><li>Scientists at Durham University created 3D videos of what it would look like if an object were to come hurtling towards an Earth-like planet in the early universe. <br /></li><li>Using the results of the study, scientists estimate that the Earth got lucky with its impact that created the Moon.<br /></li></ul>A supercomputer can do many things, including creating 3D simulations of what it may look like when Earth faces a giant impact. Scientists used the COSMA supercomputer to show exactly what would happen to an Earth-like planet in the early universe if a giant object were to smash into its atmosphere.<br /><br />Planets aren’t created overnight. It takes billions of years of evolution to get the rocks and gas to come together to create what can be called a planetary body. If in the middle of that formation, something smashes into the planet before its whole — it can have wide-ranging consequences, like atmospheric loss. <br /><br />The 3D videos created by scientists at Durham University and the University of Glasgow propose two different scenarios. One, where the impact is head-on and another, with a grazing impact.<br /><br /><div type="Video" msid="77098808" hostid="261" title="Supercomputer 3D-video of head-on planetary collision" dataSource="BUSINESSINSIDER" thumbUrl="https://denmark.timesinternet.in/cmslite/api/app/images.jpg?msid=77098808"></div><em>Source: Durham University</em><br /><br />Grazing impacts, like the one that’s supposed to be the Moon’s origin story, lead to much less atmospheric loss as compared to a head-on collision, according to the study published in Astrophysical Journal.<br /><br /><div type="Video" msid="77098825" hostid="261" title="Supercomputer 3D-video of grazing planetary collision" dataSource="BUSINESSINSIDER" thumbUrl="https://denmark.timesinternet.in/cmslite/api/app/images.jpg?msid=77098825"></div><em>Source: Durham University</em><br /><br />A head-on collision is more dangerous since the impact can penetrate through to the mantle — the layer that sits just above the planet’s crust.<br /><br />  <div type="image" title="earth layers" msid="77098855" hostid="261" caption="&amp;lt;p&amp;gt;Layers of the Earth&amp;lt;/p&amp;gt;"></div><br />Using the results of this study, the study estimates that Earth got lucky with its collision that created the Moon. The impact only managed to wipe out between 10% to 50% of its atmosphere. <br /><br />"In spite of the remarkably diverse consequences that can come from different impact angles and speeds, we've found a simple way to predict how much atmosphere would be lost,” said the lead author of the study, Jacob Kegerries. <br /><br />Going forward, the scientists will continue to carry out more varied simulations to test the effect varying masses and compositions have on the results. <br /><br /><strong>SEE ALSO:<br /><a href="https://www.businessinsider.in/science/space/news/nasa-new-rules-to-protect-mars-and-moon-from-earth-germs/articleshow/76906055.cms">NASA issues new guidelines to protect the Moon and Mars from Earth's germs</a><br /><br /><a href="https://www.businessinsider.in/science/space/news/uae-mars-mission-hope-probe-on-its-way-to-red-planet-here-is-everything-you-need-to-know/articleshow/77064837.cms">The Hope Probe is on its way to Mars — everything you need to know about the UAE’s first jump into interplanetary space</a><br /><br /><a href="https://www.businessinsider.in/science/space/news/pictures-of-comet-neowise-in-swiss-alps-stonehenge-and-other-parts-of-the-world/slidelist/77034838.cms">IN PICS: Comet NEOWISE spotted blazing from the Stonehenge to the Swiss Alps, in skies all over the world</a><br /><br /></strong><br />

WATCH: Supercomputer generates 3D videos that show how Earth may have lost half of its atmosphere to create the Moon

<br /><ul><li>The first target of the mechanism to defend the Earth against asteroids now has an official name — Dimorphos. <br /></li><li>Didymos’ smaller binary companion will be the first celestial body to have “substantially changed as a result of human intervention. ”<br /></li><li>The National Aeronautics and Space Administration’s (NASA) Double Asteroid Impact Test (DART) will collide with Dimorphos at 6.6 kilometers per second to change its trajectory.</li></ul>In Earth’s endeavour to defend itself against asteroid impacts, the first target Asteroid Impact Deflection Assessment (AIDA) <keyword id="9636614" type="UNKNOWN" weightage="20" keywordseo="planetary-defence-mission">planetary defence mission</keyword> has been dubbed Dimorphos by the International Astronomical Union (<a href="https://www.iau.org/news/pressreleases/detail/iau2007/">IAU</a>).<br /><br /><div type="Article" hostid="261" msid="70956700" title="NASA and the European Space Agency are meeting to defend the Earth against asteroids" mstype="2" mssubtype="0"></div><br />In the past, it has held many titles from Didymoon to S/2003 (65803) — it’s provisional designation — but it did not have an official name. It was only when it was chosen as the ideal candidate to test Earth’s outer space defences did the question of a permanent designation come into play.<br /><br />The primary reason for the official designation was so that it will be easier to distinguish Dimorphos from its primary companion — Didymos. “As the target of the DART and Hera space missions, it will become the first celestial body in cosmic history whose form was substantially changed as a result of human intervention,” <a href="https://www.iau.org/news/pressreleases/detail/iau2007/">said the proposal</a> sent to IAU.<br /><br /><strong>Knocking an asteroid off its course<br /></strong>The two-part mission involves the National Aeronautics and Space Administration’s (NASA) Double Asteroid Impact Test (DART) to collide with Dimorphos followed by the European Space Agency’s (ESA) Hera satellite which will go in to assess the impact.<br /><br />DART is meant to knock the asteroid off its course to determine if the mechanism can work to change the route of an asteroid that might be headed directly for Earth. It will travel at a speed of 6.6 kilometers per second to break the space rock into smaller pieces with help from its onboard camera — DRACO — and autonomous navigation software.<br /><br />An Italian CubeSat, LICIACube, will be flying alongside DART to record the impact and send the data back to the on-ground team. It’s set to launch one year from now in July 2021 and will take another year to reach its target. <br /><br />ESA’s space probe will follow in 2024. The aim of analysing the asteroid after the impact is to figure out if the planetary defence mechanism can be made more efficient. <br /><br /><strong>Dimorphos will not hit Earth<br /></strong>The primary asteroid, Didymos, or its binary companion and target, Dimorphos, don’t pose any threat of actually hitting Earth. <br /><br /><div type="Article" hostid="261" msid="70893317" title="For an asteroid to wipe out humans, it has to be bigger than the one that killed the dinosaurs" mstype="2" mssubtype="0"></div><br />The reason it has been chosen as the first target is that it’s the most easily reachable asteroid system that is big enough. The primary body has a diameter of 780 meters and Dimorphos is around 160 meters in diameter — around the same size as the Great Pyramid in Egypt.<br /><br /><strong>SEE ALSO:<br /><a href="https://www.businessinsider.in/science/space/news/pictures-of-comet-neowise-in-swiss-alps-stonehenge-and-other-parts-of-the-world/slidelist/77034838.cms">IN PICS: Comet NEOWISE spotted blazing from the Stonehenge to the Swiss Alps, in skies all over the world</a><br /><br /><a href="https://www.businessinsider.in/science/space/news/nasa-gets-35-million-to-make-sure-asteroids-dont-destroy-earth/articleshow/72996562.cms">NASA gets $35 million to make sure asteroids don't destroy Earth</a><br /><br /></strong><a href="https://www.businessinsider.in/science/space/news/nasa-and-elon-musks-spacex-plan-to-send-up-four-more-astronauts-to-the-iss-in-september/articleshow/77122857.cms"><strong>NASA and Elon Musk's SpaceX plan to send up four more astronauts to the ISS in September</strong></a><br />

NASA and Europe’s first target to keep an asteroid from hitting Earth has officially been dubbed Dimorphos

<p></p><div class="KonaFilter image-container display-table"><div><div class="image on-image"></div><p></p></div></div><p>On January 4, NASA announced <a href="http://www.businessinsider.com/nasa-new-asteroid-missions-2017-1">two new space missions</a> to explore the solar system: Lucy, a probe that will visit swarms of ancient asteroids lurking near Jupiter, and Psyche, which will orbit the all-metal core of a dead planet.</p><p>These winners of the Discovery program, as it's known, will each get $450 million to build their robots, plus a rocket to launch them.</p><p>"This is what Discovery Program missions are all about - boldly going to places we've never been to enable groundbreaking <keyword id="41551" type="ENTERTAINMENT" weightage="100" keywordseo="science">science</keyword>," Thomas Zurbuchen, the associate administrator of NASA's Science Mission Directorate, said in <a href="https://www.nasa.gov/press-release/nasa-selects-two-missions-to-explore-the-early-solar-system">a Jan. 4 press release</a>.</p><p>But in a pile of rejected finalists, sitting alongside two conceptual <a href="http://www.businessinsider.com/venus-deadly-surface-conditions-2016-12">missions to Venus</a>, is a space telescope that might one day save countless lives on Earth from a killer asteroid: a threat Zurbuchen himself <a href="http://www.jpl.nasa.gov/news/news.php?feature=6669">has said</a> is "not a matter of if - but when."</p><p>It's called the <a href="http://neocam.ipac.caltech.edu">Near-Earth Objects Camera</a>, or NEOCam, and it promises to discover tens of thousands of rogue space rocks roughly 460 feet (140 meters) in diameter or bigger. That size is by design: Congress <a href="https://www.gpo.gov/fdsys/pkg/PLAW-109publ155/pdf/PLAW-109publ155.pdf">passed a law in 2005</a> charging NASA - as one of its seven explicitly stated goals - to find 90% of such near-Earth objects (NEOs) by 2020.</p><p>The reason is because asteroids and comets of this size are notoriously difficult to detect, yet can slug our planet or explode in our atmosphere with the energy of least 60 megatons' worth of TNT. That's more powerful than the largest <a href="http://www.businessinsider.com/trump-nuclear-weapons-expansion-risk-2017-1">nuclear weapon</a> ever detonated.</p><p>"You do that over a city, and it's a very, very bad day," <a href="https://www.psi.edu/about/staffpage/sykes">Mark Sykes</a>, director of the Planetary Science Institute and a scientist on the NEOCam team, told Business Insider. "It's important to look at your neighborhood, from a planetary defense standpoint."</p><p>While NASA did commit to partially fund NEOCam for a year, it's effectively the space agency's third pass on launching the telescope in a decade. (The mission was submitted in two previous rounds of Discovery.)</p><p>Meanwhile, NASA is running years behind its Congressional mandate to find NEOs, and Earth is mostly blind to threats that might one day level a city.</p><p>Just this past Monday, for instance, an asteroid possibly as large as a 10-story building <a href="http://www.businessinsider.com/asteroid-flyby-nearer-than-moon-2017-1">flew past Earth closer than the moon</a> at 9.8 miles per second (15.7 kilometers per second) - and yet astronomers only learned of its existence 2 days beforehand.</p><h2>We live on a moving target for killer space rocks</h2><p></p><div class="KonaFilter image-container display-table"><div><div class="image on-image"></div><p></p></div></div><p>Astronomers like to say Earth is drifting through a cosmic shooting gallery.</p><p>It's no wonder why.</p><p>Any space rock that zooms within 125 million miles (200 million kilometers) of Earth is considered an NEO, and - so far - humanity has located about <a href="http://neo.jpl.nasa.gov/stats/">15,500 such objects</a>. Relative to Earth, the average one is about <a href="http://www.jpl.nasa.gov/news/news.php?feature=6664">30 million miles</a> (50 million kilometers) away and moving <a href="https://spaceguardcentre.com/what-are-neos/near-earth-objects-impact-effects/">between</a> 27,000 mph (12 kilometers per second) and 45,000 mph (20 kilometers per second) - akin to flying the length of Manhattan once a second.</p><p>About 9% of these NEOs, or some <a href="http://neo.jpl.nasa.gov/neo/groups.html">1,759 space rocks</a>, are called "potentially hazardous" objects (PHOs), meaning they come within 4.6 million miles (7.48 million kilometers) of Earth.</p><p>Their sizes vary wildly, so a strike could mean anything from broken windows, like the <a href="http://www.businessinsider.com/no-one-saw-chelyabinsk-meteor-over-russia-coming-could-happen-again-2016-4">2013 asteroid-caused air burst over Chelyabinsk, Russia</a>, to global extinction, like the impact that helped <a href="http://www.businessinsider.com/dinosaur-extinction-may-have-been-affected-by-slow-egg-incubations-2016-12">wipe out the dinosaurs 65 million years ago</a>.</p><p>The animation below, <a href="http://www.businessinsider.com/asteroids-near-earth-animation-youtube-2016-3">by Scott Manley</a>, shows what the playing field looks like these days, and it is not comforting. Planets are teal (Earth is the third one from center), yellow and red show NEOs (red means they cross Earth's orbit), and green shows more distant, main-belt asteroids:</p><p>But these are just the ones we know about.</p><p>Roughly 72% of all NEOs that are 460 feet (140 meters) or larger have <em>not</em> been found, according to the "<a href="https://www.whitehouse.gov/sites/default/files/microsites/ostp/NSTC/national_neo_preparedness_strategy_final.pdf">National Near-Earth Object Preparedness Strategy</a>", a report published by the White House's National Science and Technology Council (NSTC) in December 2016. This amounts to about 25,000 nearby asteroids and roughly 2,300 hazardous ones.</p><p>That doesn't mean we shouldn't be worried about smaller space rocks, though; in fact, quite the opposite.</p><p>"An asteroid much smaller, just 45 meters [150 feet] across, exploded in 1908 over Tunguska with an explosive energy of several megatons and destroyed an area as large as New York City," <a href="http://stanford.edu/~rdb3/">Roger Blandford</a>, a physicist at Stanford University, wrote in <a href="http://spacenews.com/op-ed-policing-the-cosmic-neighborhood/">a September 2015 op-ed for Space News</a>. "Congress calls these smaller asteroids 'city killers,' and although they are 30 times more numerous, we have located less than 1% of them."</p><p>In raw numbers, "over 300,000 objects greater than 40 meters [130 feet] in size could be an impact hazard to the Earth and have not yet been detected," according to NSTC's report.</p><p>The chart below, recently created by NASA's Jet Propulsion Laboratory and Caltech, sums up the gaping holes (in green) of NEO survey efforts thus far:</p><p></p><div class="KonaFilter image-container display-table click-to-enlarge"><div><div class="image on-image"><a title_source="NASA/JPL-Caltech" title_caption="Fewer asteroids exist than previously thought, but smaller space rocks elude easy detection." class="zoomin" href="https://static-ssl.businessinsider.com/image-960/587564a8f10a9a283f8b5274-2400"><span class="sprites click-to-enlarge-icon" title="Click to enlarge"></span></div><p></p></div></div><p>If you're a space rock, you reflect sunlight. Telescopes that are looking in the right place at the right time can see you as a dot sneaking across the blackness of space, allowing scientists to calculate your mass, speed, orbit, and the odds that you'll smack into Earth.</p><p>If you're a small NEO, though, you aren't very bright. This means a telescope has to be very big and use very advanced hardware to find you - but big, bad telescopes are expensive and take a very long time to build and calibrate.</p><p>Take the Large Synoptic Survey Telescope (LSST), for example, which is one of Earth's best current hopes of finding killer asteroids. The project broke ground in 2015 and is expected to <a href="https://www.lsst.org/sites/default/files/ProjectOverviewKahnLSST2014.pdf">cost upwards of $465 million to build</a>. Based on its current <a href="https://www.lsst.org/about/timeline">construction schedule</a>, it won't be fully operational until late 2021, at the soonest, or able to fulfill the 90% detection goal set by Congress until the mid-2030s - more than a decade behind-schedule.</p><p>LSST, like all ground-based observatories, also comes with two major limitations.</p><p>The first: "You can't see asteroids near the sun. You're blinded by the sky," Sykes said. "Right now we have to wait until those pop out in front of us. To get those guys, you really need to be in space - where you're not blinded by the sky."</p><p>Sykes said the other snag is that ground-based telescopes mainly rely on visible light for detection.</p><p>"If [an asteroid] has a dark surface, it's going to be very hard to see," he said.</p><p></p><div class="KonaFilter image-container display-table float_right"><div><div class="image on-image"></div><p></p></div></div><p>NEOCam goes after these two problems by being in space, where no atmospheric gases get in the way, and by using an advanced, high-resolution infrared (IR) camera.</p><p>IR light is a longer wavelength of light that's invisible to our eyes, but if a source is strong enough - say, a roaring fire - we can feel it as warmth on our skin.</p><p>Sun-warmed asteroids emit infrared light, even when they're coasting through the void, or are too dark for ground-based telescopes to see. Which means NEOCam could spot them <a href="http://neocam.ipac.caltech.edu/page/whyinfrared">by their heat signatures</a>.</p><p>The approach works. The prime example is NASA's 8-year-old Wide-field Infrared Survey Explorer (WISE) telescope, which has found <a href="http://neo.jpl.nasa.gov/stats/wise/">at least 230 NEOs and 42 PHOs</a> from orbit.</p><p>However, it's a less powerful telescope, has a smaller field of view, an older camera that requires cryogenic cooling (NEOCam's does not), and wasn't designed solely to hunt asteroids. While scientists gave it a new mission to do so in 2013, <a href="http://neowise.ipac.caltech.edu/">renaming the project NEOWISE</a>, the telescope is scheduled to end operations in March 2017.</p><p>"[A] space-based observatory, working in concert with observations from ground-based telescopes, may be the best approach to detecting, tracking, and characterizing the NEO population," the NSTC's December 2016 report states. "This combination would more rapidly complete the survey of objects larger than 140 meters [460 feet] while greatly improving our understanding of the hazard from the 50-140 meter [160-460 feet] NEO population."</p><p>The NEOCam team proposed to launch in 2021 and find two-thirds of missing objects in the larger-than-460-feet (140 meters) category within 4 years - about a decade ahead of LSST's schedule.</p><p>This would help address the NSTC's concern on the issue:</p><p style="padding-left: 30px;">"Finding NEOs as early as possible is the first priority for planetary defense, in order to give adequate time to make decisions and implement courses of action. This fact must be stressed: the earlier a NEO threat is detected, the better the emergency response to the threat will be."</p><p>So if launching a capable replacement for NEOWISE is a priority, why didn't NASA pick it?</p><h2>The forces keeping NEOCam grounded</h2><p></p><div class="KonaFilter image-container display-table"><div><div class="image on-image"></div><p></p></div></div><p>Only NASA knows why it didn't pick NEOCam for launch, but it isn't telling anyone, not even Sykes and his colleagues - at least not yet.</p><p>The space agency first wants to debrief the NEOCam team on the snags it saw with of its <a href="https://discovery.nasa.gov">Discovery program</a> proposal, a meeting that a NASA representative said will happen as early as next week.</p><p>"The Discovery review process identified strengths and weaknesses for all 5 mission proposals. As with Lucy and Psyche, NEOCam will be asked to address any issues that were raised in the review," David Schurr, deputy director of NASA's planetary science program, told Business Insider in an emailed statement.</p><p>During NEOCam's debriefing, the space agency will "work and negotiate with the [...] team" on a funding level for the next year, <a href="https://science.nasa.gov/about-us/leadership/dr-jim-green">Jim Green</a>, director of NASA's planetary science division, told reporters during a Jan. 4 NASA teleconference.</p><p>"Whether it's a drip or a flood, we'll find out soon," Sykes said.</p><p>After that year of funding runs out, however, all bets are currently off: NASA will have to "<a href="https://twitter.com/jeff_foust/status/819226787305627648">look for money</a>" under a new presidential administration, according to Green, if it wants to keep the project alive. ("No flow, no go," Sykes said.)</p><p>The hangup with NEOCam is not likely any lack of engineering prowess - "the rumor is that there were no major weaknesses [with the proposal]," one source who asked not to be named told Business Insider - but rather a bureaucratic technicality: a case of trying to jam a square peg into a round hole.</p><p></p><div class="KonaFilter image-container display-table float_right"><div><div class="image on-image"></div><p></p></div></div>That's because the mandate of NASA's Discovery program is to pull off scientific "firsts" in the solar system.<p>An unprecedented mission to the metal core of a dead planet fits the bill, while a space-based asteroid detector is something humanity already tried with WISE (the NEO hunter launched in 2009).</p><p>But Sykes contends that NEOCam is a truly unique mission that could help NASA pull off its next planned era of crewed exploration - <a href="http://www.businessinsider.com/trump-nasa-mars-sample-return-mission-2016-12">to near-Earth asteroids</a> - by locating most of the remaining NEOs of interest.</p><p>"If we want to send people beyond low-Earth orbit, an asteroid costs much less than the surface of the moon or Mars," Sykes said. "We can identify targets that are quick-turnaround times of weeks or months, to minimize the radiation exposure [in deep space] to astronauts."</p><p>In addition, Sykes said, finding perhaps tens of thousands of new NEOs would lay more groundwork for efforts to <a href="http://www.businessinsider.com/the-value-of-asteroid-mining-2016-11">mine asteroids for precious metals</a>, gather fuel for deep-space exploration, and other novel (and scientific) human endeavors.</p><p>Former astronaut <a href="https://b612foundation.org/our-team/#ed-lu">Ed Lu</a>, who's also a co-founder of <a href="https://b612foundation.org">the B612 Foundation</a> - a group dedicated to launching its own NEO-detecting space telescope, called <a href="https://b612foundation.org/sentinel/">Sentinel</a> - has grown impatient with the delays.</p><p>To get an asteroid hunter off the ground, Lu said, NASA needs to try something new, and fast.</p><p>"[T]here should be an open competition based on a planetary defense rather than a science requirement, as with the Discovery mission," Lu told Business Insider in an email. "Detecting dangerous asteroids is a concern of national security, not just science."</p><p>Blandford, the Stanford physicist, hit this message home in <a href="http://spacenews.com/op-ed-policing-the-cosmic-neighborhood/">his Space News op-ed</a>.</p><p>"[P]lanetary defense is currently treated as a scientific issue, and forced to compete with other science missions," he wrote, "instead of being seen as a long-term imperative for the protection of humanity."</p><p><em>Kelly Dickerson and Paul Szoldra contributed to this post.</em></p><div><div style="position:relative;padding-bottom:59%"></div></div>    <div class="margin-top">        <h3>NOW WATCH: <a href="http://www.businessinsider.com/molten-salt-reactor-technology-power-world-millions-years-2016-12">This Cold War-era technology could safely power the world for millions of years</a></h3>        <div>            <div>        <div class="ooyala-video-player" data-video-autoplay="false" data-video-id="hoOXhiODE6mtYAnzOSgYhFwj_jwPpGtb" data-player-variable="ooyalapopvideo" id="ooyalaplayer_popvideo" style="width:1280px;height:720px"></div>        </div>        </div>            </div>

You Searched For "comet neowise spotted" and got 11 results

How to see Comet A3, which could be the best comet in a decade. Neanderthals walked the Earth last time it flew by.

Morgan McFall-Johnsen

Comet Neowise will burn bright over India for the next 20 days after two earlier comets fizzled out

Prabhjote Gill

IN PICS: Comet NEOWISE spotted blazing from the Stonehenge to the Swiss Alps, in skies all over the world

Prabhjote Gill

Comet Neowise is a dazzling sight, but it's also a reminder of how woefully unprepared we are for dangerous asteroids

Morgan McFall-Johnsen

Comet Neowise, a meteor, and a mysterious aurora-like phenomenon called STEVE all share the night sky in one incredible photo

Morgan McFall-Johnsen

Comet Neowise is easily visible in the night sky this week. Here's when and where to look for it.

Morgan McFall-Johnsen

A bright comet is heading towards Earth and could outshine the stars in the sky, say astronomers

Marianne Guenot

In a NASA simulation of an asteroid impact, scientists concluded they couldn't stop a space rock from decimating Europe

Aylin Woodward,Morgan McFall-…

WATCH: Supercomputer generates 3D videos that show how Earth may have lost half of its atmosphere to create the Moon

Prabhjote Gill

NASA and Europe’s first target to keep an asteroid from hitting Earth has officially been dubbed Dimorphos

Prabhjote Gill

This space mission could save Earth from killer asteroids - but NASA keeps hitting the snooze button

Dave Mosher

Popular Keywords

Buying Guides