There are likely to be billions, if not trillions, of planets in our galaxy. The vast number leads many to wonder if any of them are like our home planet. A new telescope could provide an answer. The Habitable Worlds Observatory, a NASA-backed telescope, aims to help researchers find Earth-like planets and potential signs of life. It’s set to launch in the 2030s.
Kevin France, a professor of astrophysics at the University of Colorado Boulder, is part of the project's team. He spoke on a recent episode of In The NoCo with KUNC’s Erin O’Toole to share more about the research. He says the technology will allow scientists to glimpse planetary systems previously hidden from view.
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Here’s a look at that conversation:
Erin O'Toole: How do researchers define a habitable world? What? What are the characteristics they need to have?
Kevin France: It's a very Earth-centric view that we have. So the first thing that we think we need to be in is the “Goldilocks zone,” the habitable zone, which essentially just means the planet is orbiting at some distance where water could stay liquid on a surface for some part of the year.
But that's a very simplified version of what might make a habitable planet after that. We think that, you know, it needs to have an atmosphere that's maybe similar to what we have here on Earth, and it needs to have the right type of star. You know, here on Earth, we live around a very kind of average middle-aged yellow star. So, you need to kind of find the right combination of star and planet to have a good chance.
O'Toole: Habitable Worlds Observatory is expected to launch sometime in the late 2030s. It's going to sit somewhere between the Earth and the Sun. Why place it there?
France: So there's a special place in space called a Lagrange point where the gravity from all of those major bodies more or less cancels out. So if we put a spacecraft there, it's not getting tugged too hard in any one direction. It can stay in a stable position there for a long period of time. We don't have to take a whole bunch of extra fuel to do thrusters to keep it in place. So it's a pretty good place to drop a spacecraft if you want it to work for 10 or 20 years.
O'Toole: What part of the work is being done in Boulder?
France: In Boulder, specifically, at the Laboratory for Atmospheric and Space Physics, we have a long history of building instruments for NASA missions. We build things for astronomy. We built stuff for the Hubble Space Telescope. We build things that go to the outer planets. And so right now we're working on the science of the Habitable Worlds Observatory.
O'Toole: How will this observatory differ from existing space telescopes like Hubble or James Webb in terms of what it can do and what it can detect?
France: You can sort of think about it as a super Hubble Space Telescope. It operates along the same wavelengths of the electromagnetic spectrum as Hubble, but it has about 10 times the collecting area, so it's going to be able to take sharper pictures and see farther into space. But probably most importantly, it has an instrument that we call a coronagraph, and the coronagraph is there to block out the bright light from the parent star, the host star, and so we can see the faint planetary system that's orbiting it. So we have to have this coronagraph to block out that bright light so we can actually see the faint Earth-like planets that are in that system.
O'Toole: So that coronagraph is kind of like when you're looking at the night sky, but there's a street light, and you have to kind of put your hand up to block that light?
France: That's exactly right. And you know the term actually comes from what happens when we have an eclipse, where the moon goes in front of the sun's disk, and we actually can see the corona of the sun. And so that's like nature's coronagraph, but we need to make an artificial coronagraph to go out and do this experiment for other stars.
O'Toole: As someone who has made a life's work out of astronomy, Kevin, what do you hope the observatory will find?
France: So I'm actually torn. Half of me wants to find Earth-like planets and the signs of life similar to what we have on Earth, and I want them to be all over the place. But the other part of me wants to find something that we completely did not expect.
One amazingly intriguing possibility is that we don't find any Earth-like planets out there, and it would make us question our place in the universe, because we know that there are tons of stars, and we know there are tons of planets. The possibility that we might be the only one where life has happened would be a really interesting outcome. The other opportunities are that maybe there are signs of life that are not exactly like it happens here on Earth. We have a carbon-based ecosystem here, right? It's very possible that things happen differently on other worlds, and I hope we have the opportunity to kind of figure that out.
O'Toole: Is there an element in this work of finding a Plan B planet? In case climate change or, you know, a looming asteroid strike or some other disaster makes Earth uninhabitable?
France: So we do plan on using the Habitable Worlds Observatory for what we call planetary defense, which is being able to identify asteroids that may impact Earth very, very early, so we might be able to do something about them.
So that's a little bit different than what you asked. You know, there is also the search for what about the nearest star systems if they have an Earth twin that we might be able to visit someday. So Habitable Worlds will tell us which of those nearby stars are the best candidates for that.
