Another Earth might exist right next door - and this dinky DIY telescope may be the first to see it
The first telescope to photograph a "pale blue dot" of another Earth in a distant solar system may not be funded by NASA, the European Space Agency, or some other government agency.
It might come from Kickstarter.
Dubbed Project Blue, the effort isn't run by hucksters out to peddle unrealistic technologies. A consortium of professional scientists and engineers, some of whom work at NASA, is running the show as a nonprofit called Mission Centaur.
"We're looking for a place that could support life," Supriya Chakrabart, an optical and space scientist at University of Massachusetts Lowell who's part of Project Blue, told Business Insider.
They say the money will go toward further design and research of the project.
The group ultimately expects the mission to cost between $25 and $50 million to get into orbit around Earth within the next 4 to 6 years. That pricetag includes sharing a ride on a rocket like SpaceX's Falcon 9, and it's nothing compared to the billions NASA has spent on space observatories.
Once in orbit, an epic 2-year stare-down would begin.
Chakrabart said he's confident that crowdfunding the first stage of Project Blue will work out, buying time to attract a big following - and bigger funders later on.
"After ghosts and dinosaurs, space comes a close third, in terms of people's interest," he said.
Shooting in the dark
Project Blue's target is Alpha Centauri, a system that contains two of the closest stars to our own solar system at just 4.4 light-years away.
One of the stars, called Alpha Centauri A, is even sun-like.
However, nobody actually knows if a blue marble like Earth - a world with liquid-water oceans, a cozy atmosphere, and other conditions necessary for life - might lurk in the double-star system. Not even Hubble, the planet-hunting Kepler space telescope, or other advanced observatories could tell an astronomer.
So it's a bit of a gamble to make even a small telescope that's purpose-built to stare down one star system.
But Chakrabart and the other Mission Centaur scientists think it's a good bet. They cite the most recent planet-hunting data from Kepler, which pegs the odds of a rocky planet orbiting a star's "habitable zone," or close enough to create liquid water, near 85%.
"Roughly one out of every two stars has a potentially habitable planet," said Ruslan Belikov, an astrophysicist at NASA Ames Research Center, in "The Search for Earth Proxima" - a short documentary about the project. "The number of potentially habitable planets in our galaxy alone is greater than the number of people alive on Earth."
According to Lee Billings at Scientific American, Belikov and another scientist in 2014 pitched NASA a telescope similar to Project Blue, "but the agency passed over the speculative, narrowly focused project."
That's not too much of a surprise, since NASA likes its space telescopes more like Swiss Army knives and able to view multiple targets with ease. The equipment and techniques also weren't quite there at the time - hurdles that Mission Centaur no longer foresees.
"The technology required to do this is only very recent. It hasn't been ready until now," Brett Marty, the filmmaker behind the aforementioned documentary and the executive director of Mission Centaur.
How to photograph an 'Earth Proxima'
At roughly the size of a modest washing machine, Project Blue would be pretty dinky space telescope if built - certainly compared to the school bus-size Hubble space telescope.
But it doesn't need to be large. It's only focused on one part of the sky and needs minimal electronics (whereas Hubble needs large gyroscopes and multiple cameras to move and take aim at different objects in space).
Project Blue's ultimate task is resolving any very dim objects next to ones 1 billion to 10 billion times brighter.
"Imagine there's a marble next to a lighthouse in Cape Cod," Chakrabart said. "Ok, now try to image that marble from San Francisco. That is what we're dealing with."
He said that "three key technologies matured enough that we can tell people with a straight face that we're now actually ready to go and do this thing."
One is a miniaturized version of a coronagraph, a complex instrument that can blocks each star's blinding light and can reveal planets hiding in the glare.
"It's kind of like playing tennis and the sun is in your eyes," Marty said. "When you put your hand up to block it, you can see the ball coming. Here we're suppressing both stars at once" and catching the balls. Keeping the precision while shrinking what's normally a very large instrument wasn't easy, they said.
The next challenge was that "it's near impossible to make a perfect mirror," or at least a large one, Chakrabart said.
The solution? A "deformable" mirror, which is a computer chip-like array of about 1,000 ultra-tiny (and very perfect) mirrors that can be programmed to move with microscopic precision thousands of times a second, helping cancel out any optical imperfections in the telescope.
The third and final technical hurdle to making Project Blue possible was image stabilization.
"A crisp image is what is needed because the planet would be so close to the star," Chakrabart said. "We have built such a system and proven it works to the level Hubble can point."
Marty said it's similar to the gyros in consumer cameras that stabilize an image - though far more exacting. "This is really the reason we're able to do this mission at such a low cost," he said.
To prove the stabilizers worked well enough to keep Project Blue gazing endlessly at Alpha Centauri, Chakrabart's team launched experimental prototypes toward the edge of space, some 60 miles up. For the few minutes they floated in the thin air before falling back to Earth, they perfectly stabilized the experimental rig.
If all goes according to plan, Project Blue will take hundreds or even thousands of pictures of the star system in three colors (including blue), merge the giant pile of images, and lift out a pale blue dot out from the noise of pixels.
"We have to take care of every single possible event that could contribute to this noise," Chakrabart said. "This is why we've decided we need at least 2 years of measurement to convince ourselves we're seeing a true, Earth-like planet."
What if it works?
It's important to note this isn't the closest star system we heard a lot about earlier this year, a red dwarf star called Proxima Centauri.
Although a dogged team of astronomers strongly believe there's a rocky, Earth-size planet called Proxima b circling that star in its habitable zone, Chakrabart and Marty said it's not a great target for their ragtag operation.
At about 4 million miles away from its star, Marty said, "there's a lot of radiation. It's also a tricky target and hard to resolve, and it might not be anything like our planet."
An observatory like the behemoth James Webb Space Telescope might be the first to study that world, though it wouldn't be a "pale blue dot" photo - more like a fuzzy heat signature that could indicate "this is an incinerated hell hole" or "a useful atmosphere and potentially water lurk here."
Project Blue, of course, actually intends to return images of a habitable planets, like this:
If it works, Russian billionaire Yuri Milner and his Breakthrough Starshot project - an effort to laser-propel tiny spacecraft to the Alpha Centauri or Proxima Centauri systems - will have an intriguing new target.
But even if that pie-in-the-sky idea falls down and all we're left with is an image of a pale blue dot, it would be Earth-shattering.
"Finding an Earth Proxima would be a transformative event in the history of mankind," said Bill Diamond, president and CEO of th SETI Institute, in Marty's documentary. "I would love to think that is something that helps bring us together. It's a very unifying thing."
And in divisive times like these, unity is something the human race could use a lot more of.