Researchers at the University of Colorado Boulder Laboratory for Atmospheric and Space Physics are helping to lead planning efforts for NASA's next major space telescope -- and its purpose will be to explore whether life exists beyond Earth.
NASA's Habitable Worlds Observatory, planned to launch in the late 2030s, will be the first space telescope specifically designed to search for Earth-like planets and analyze them for evidence of life or evidence that they can support life.
"I think answering the question of are we alone in the universe is one of the oldest philosophical questions that humankind has," CU Boulder professor Kevin France said. "And I think we're really lucky to be at a place where we might have the technical capabilities to answer this question in our lifetime."
France was one of 15 people chosen this summer to be on the Habitable Worlds Observatory's Community Science & Instrument Team, a group leading the science planning during the telescope's early development and planning phase.
"One of the things the mission is going to be designed to do is to survey ... nearby sun-like stars to search for signs of Earth-like planets," France said. "And then, not just find the planets, but also investigate their atmospheres to search for signs of life."
Since the 1990s, when people first started discovering other planets outside our solar system, humanity has discovered almost 6,000 extrasolar planets, France said. Now there are questions about whether an "Earth 2.0'' exists, he said, including if it can be found, how common planets like it are and if they can support life like on Earth.
The new telescope will investigate whether any planets have water, oxygen or methane that would indicate signs of life. The target lists for the exact planets and stars the telescope will look at are still being defined, France said, but the most promising systems will probably lie within about 75 light-years from Earth.
"That is a huge number if you convert it to meters or miles, but on the scale of the Milky Way galaxy, it's really in our galactic backyard," France said.
One key feature the telescope will have is a starlight suppression system that will allow scientists to block out the bright glare from the parent sun so they can observe the planet.
"This is really going to drive how stable the telescope needs to be, what size the telescope needs to be, how the instruments that perform the starlight suppression work," France said. "That's one big area."
The Habitable Worlds Observatory will probably be roughly the same size as the James Webb Space Telescope, or a little larger, France said. The James Webb telescope's primary mirror is about 21.3 feet in diameter. The primary mirror of the new telescope will likely be about 21 feet to 26 feet in diameter, France said. Mirrors are a key function of telescopes, used to collect and focus light.
The Habitable Worlds Observatory will also carry a set of instruments to provide a platform for scientists to conduct potentially transformational astrophysics that could help answer questions about how galaxies evolved and where Earth's solar system came from.
Brian Fleming, a CU Boulder LASP research professor, was a co-chair of an ultraviolet science and technology working group that guided NASA on implementing ultraviolet technology for the Habitable Worlds Observatory.
"(Habitable Worlds) is also going to be able to do so much more for astrophysics. We're going to be able to really delve into how galaxies evolve and interact with our surroundings, which is really important ...," Fleming said. "How did the area around the solar system form and evolve? It's all tied to this big cosmic cycle about how energy and material flow into and out of galaxies and through them. It's a whole process of feedback from different sources that are exploding and forming and winds that are blowing, and we really have a hard time with our current capabilities following that cycle."
New, more sensitive ultraviolet instruments on the telescope will allow it to see and observe more of space at one time by expanding the wavelengths of light it can observe.
"For decades we've used and loved Hubble, but it's the only thing that's been capable of doing any of the science that we do in ultraviolet, which is the study of really some of the most energetic and also common objects in the universe," Fleming said. "... With Habitable Worlds, we'll be taking a real leap forward."
The ultraviolet instruments are what will make Habitable Worlds able to study nearby galaxies, gases, clouds and stars. At his lab at CU Boulder's LASP, their team designed an ultraviolet instrument, the Large Ultraviolet Optical Infrared Surveyor, that NASA's project office wants to study for potential Habitable Worlds applications. While Fleming said he and his team would like to be involved with developing instruments for the new telescope, NASA is still developing the concept of the observatory, and no decisions on that have been made.
"We, like many members of the (space) community, are involved in helping that formulation along," Fleming said. "(We are) helping NASA (and) advising NASA when we can about what the observatory needs to do and what it can do based on what we do in our labs."
Fleming is hopeful that CU Boulder and LASP will remain involved as the Habitable Worlds Observatory project continues.
"We were the institution that led one of the major ultraviolet instruments on Hubble, so we kind of have a heritage as an institution in this kind of instrument development on the last big observatory," Fleming said. "We're continuing that now ... and it's something that we'd like to continue to do on Habitable Worlds."