NASA is finally advancing a space telescope that could track down dangerous asteroids before they strike Earth

• A NASA space telescope could help track down 90% of asteroids big enough to crush New York.
• NASA is finally advancing the telescope, called NEO Surveyor, after years of passing it over.
• By passing a key review, the telescope has escaped what one expert called "NASA mission limbo hell."

NASA is finally moving forward with a space telescope that could spot asteroids heading dangerously close to Earth.

The Near-Earth Object Surveyor Mission - NEO Surveyor, for short - has passed a key review, and NASA announced Friday that it's moving it to the next stage of development. Now engineers can start building new parts for the telescope, thereby keeping the mission on track for a 2026 launch.

"I'm over the moon," Amy Mainzer, who leads the project, told Insider. "We are excited to do our part to help cross the asteroid-impact issue off the world's list of worries."

To protect the planet from an incoming asteroid, experts estimate they'd need five to 10 years' warning that a space rock was headed our way. Right now, an asteroid could easily approach Earth without anyone seeing it, since telescopes on the ground can only do limited surveillance.

"What you want to do is find them early, find them as early as possible - as in years, or even decades, before they pose a threat," Paul Chodas, the manager of NASA's Center for Near-Earth Object Studies, previously told Insider. "The dinosaurs didn't have a space program, and look what happened to them. We have a space program. And given enough time, we can do something about this threat."

NEO Surveyor would help NASA catalogue nearby asteroids and chart their paths through the solar system, so that someday - if necessary - humanity may have a shot at destroying or deflecting any space rocks on a collision path with Earth.

For years, work on this kind of infrared telescope had been caught in "NASA mission limbo hell," MIT astronomer Richard Binzel previously told Insider. Now the project is finally moving forward.

NASA needs a space telescope to defend Earth from city-crushing asteroids

Experts from around the world practiced for a hypothetical asteroid strike in April. It didn't go well.

At the Planetary Defense Conference, a group of 200 participants from about two dozen countries worked through a hypothetical scenario in which an asteroid was set to crash into Earth in six months. They determined that no existing technologies could stop the space rock, since the time frame was too short to launch a mission that could destroy or deflect an asteroid.

Without a space telescope like NEO Surveyor, it's very possible that an asteroid could sneak up on our planet like the one in the April simulation. It has already happened a few times.

In 2013, a house-sized asteroid screamed into the skies above Chelyabinsk, Russia and exploded. The blast sent out a shock wave that broke windows, damaged buildings, and injured more than 1,400 people. No one on Earth saw it coming. That same day, a larger asteroid came within 17,000 miles of the planet.

Jim Bridenstine, who served as the Trump administration's NASA Administrator, said in 2019 that the agency's modeling suggests an event like the Chelyabinsk meteor occurs about every 60 years.

But the Chelyabinsk rock was small - about 50 feet wide. In 2019, a 427-foot, "city-killer" space rock flew within 45,000 miles of Earth, and NASA had almost no warning about that either.

Then last August, an asteroid the size of a car passed closer to Earth than any known space rock had ever come without crashing. It missed our planet by about 1,830 miles. Astronomers didn't know the asteroid existed until about six hours after it whizzed by. Nobody saw it coming, because it was approaching from the direction of the sun.

Telescopes on the ground can only observe the sky at night, which means they miss almost everything that flies at us from the sun. NEO Surveyor, from its perch in Earth's orbit, would be able to spot such space rocks. Since it would use infrared light, it could also spot asteroids that are too dark for Earth-based telescopes.

Plans for this kind of space telescope have been in the works since 2005, when Congress mandated that NASA find and track 90% of all near-Earth objects 140 meters (460 feet) or larger in size. That's big enough to obliterate a city like New York.

The initial deadline was 2020. But NASA has only spotted about 40% of those objects so far. NEO Surveyor is designed to bring the agency up to its 90% goal within a decade of launch.

"Every day we wait is one day less that we have the information we need to make a response," said Binzel, who studies potentially hazardous asteroids. "What that means is, for now, we are relying on luck to keep us safe from major asteroid impacts. But luck is not a plan."

The NEO Surveyor team is forging ahead - maybe with a budget boost

Mainzer first submitted the idea for an asteroid-hunting space telescope in 2006. NASA declined to take it on as a mission, funding other projects instead. She submitted proposals in 2010 and 2015 as well, but the agency kept passing.

NEO Surveyor finally became an official NASA mission in 2019. Since then, the project has been in what NASA calls "Phase A" - a stage focusing on design and technology development. Now that they're moving on to Phase B, Mainzer and her team can start building prototypes and developing hardware and software.

They could soon get a major influx of cash, too. NASA's budget request for 2022 allots $197 million for planetary defense, including $143 million for NEO Surveyor - though Congress must still approve it.

That would be a significant increase from the $28 million the mission received in 2021. NASA Associate Administrator Thomas Zurbuchen estimated in 2019 that developing the telescope could cost about $500 to $600 million in total.

The budget request and Friday's Phase B approval are "double good news for citizens of planet Earth," Binzel said, though he added that now, "the ball in squarely in Congress' court."

"The clock is ticking," Mainzer said. "We really want to get off the ground as quickly as possible."

Aylin Woodward contributed reporting.