A new massive space telescope to find the next Earth

 American astronomers are demanding the development of a new suite of grandiose space telescopes that can look into the atmospheres of the planets beyond our Solar System, listen to the black holes that sound as they form in the Universe, and look back in time when galaxies first appeared. It's all part of an ambitious long-term strategy to create the next generation of tools to study the farthest reaches of space, with the hope of launching these spacecraft in the 2030s and 2040s.

Astronomers set out their vision for the future in a report known as the Decadal Survey on Astronomy and Astrophysics, published today by the National Academies of Science. Compiled every ten years, the survey is essentially a wish list detailing the missions with the highest priority that astronomers would like NASA to build in the next decade. Decades of past studies have led to the formation of some of NASA's most ambitious missions, such as the Hubble Space Telescope, which is currently orbiting the Earth, and the James Webb Space Telescope, or JWST, which is to be launched into deep space before the end of the year.

Usually, in their report, astronomers will provide a list of missions that they would most like to see before, ranked in order of priority. This year, the recommendations are a bit different. Like previous surveys, the new poll recommends building a large "flagship" space telescope - a giant that can see infrared, optical, and ultraviolet light in planets' atmospheres that are 10 billion times weaker than orbiting stars looking for signs. of life. But the report also recommends the development of two smaller telescopes - one that sees X-rays and one that see far-infrared - almost simultaneously while investing in various ground-based telescopes and space missions already in effect.

In this way, in a few decades, astronomers will have a whole fleet of new space telescopes, providing the most comprehensive picture ever of the distant Universe. Many in the scientific community are delighted with this idea. "The Decadal team has risen to the challenge," said Heidi Hammel, vice president of science at the Association of Universities for Research in Astronomy, a consortium of academic institutions that operate powerful telescopes. The Verge in an email. "They introduced the incredible science and made bold choices, both for ground and space installations. I'm so happy now. "

The biggest goal set in the Decadal Survey - and the priority of its iconic space telescope - is to find and catalog the worlds beyond our Solar System. These distant planets, known as exoplanets, were discovered only in the early 1990s. Since then, astronomers have cataloged thousands more, completely transforming our understanding of the cosmos. Now that we know that exoplanets are common, scientists are looking for one - or more - that could be home to extraterrestrial life.

 The problem is that studying exoplanets is incredibly difficult. These worlds are extremely distant, usually orbiting very bright stars that overwhelm them in the light and wash them away. This prevents astronomers from seeing the exoplanets directly. Instead, scientists must deduce their presence, either by staring at a distant star and waiting for it to fade a little - a sign that a tiny world is passing in front of it, blocking its light - or by measuring how far they sway stars due to the gravitational pull of a nearby planet.

But just knowing that there is an exoplanet is not enough to answer the ultimate question: are we alone? So astronomers are desperate to look into the atmospheres of these distant worlds to see if they might resemble ours. The culmination of the discovery of an exoplanet would be finding an exoplanet with the suitable gases in its atmosphere, parked in the habitable area of ​​a Sun-like star - a place where it is neither too hot nor too cold, allowing water to accumulate on the planet's surface. But we will never find out if we get stuck watching the stars darken and shake.

With a vast space telescope featuring a 20-foot (6-meter) antenna that can see in bright light types, astronomers believe they will finally be able to see an abundance of direct exoplanets, including those that are too faint to see now. In this way, we could find the twin of the Earth and maybe even confirm the existence of life on it. "We focus on the scientific achievements we want to see happen," said Keivan Stassun, a professor of physics and astronomy at Vanderbilt and one of the committee members who wrote the new Decade Study. "We want to discover the Earth. We want to discover habitable worlds. This is a specific scientific priority. "

To design this new giant telescope, engineers will probably rely on two proposed observer ideas that have already been outlined in detail. Before completing the ten-year study, four scientists came up with four different proposals for space telescopes, providing a framework for what future flagship missions might look like. Two of the four teams, LUVOIR and HabEx, have proposed telescopes that could search for habitable worlds. HabEx has called for a bold plan to build a stellar shadow that will fly in front of the telescope and block the light from distant stars, making their exoplanets easier to see. LUVOIR has ordered a monster space telescope that looks a bit like NASA's future JWST spacecraft, which has been completely modernized. HabEx's proposed budget was between 8 and 10,

The decade-long survey does not specifically recommend the construction of either HabEx or LUVOIR. However, the report notes that HABEx was not ambitious enough in its scope and that LUVOIR was a little upset about the budget. Instead, the report simply sets out what the astronomical community wants these telescopes to do, which should help inform their final design. The researchers who worked on these projects are quite happy with the decision.

"It's amazing," says Scott Gaudi, a professor of astronomy at Ohio State University and co-chair of the HabEx co-community. "It's the best possible outcome I could have hoped for, not just for myself, but for all the people who worked on these great mission concepts."

The search for habitable worlds is not the only goal of the astronomical community for the next ten years. He also wants to know more about the densest objects in our Universe, such as black holes and neutron stars, and the cataclysmic events that give them to. Astronomers also want to look inside distant galaxies as they form to learn more about how they evolve and give birth to millions of new stars.

There is much to be done, which is why the ten-year survey requires more than a new spaceship. The authors say that adding an X-ray telescope and a far-infrared telescope will be the best way to accomplish these tasks. To get everything they want, the report's authors propose that mission planners immediately begin developing the large exoplanet-hunting telescope, outlining precisely the technologies they will need to start building the spacecraft. If this process goes well in the next five years, it will be time to design the X-ray and far-infrared telescope. All these vehicles can then be developed and built at about the same time.

It seems like a bold plan, significantly, since space telescopes usually exceed the budget. NASA's next large space telescope, the JWST, was initially scheduled to launch in 2007 and cost less than $ 1 billion. It is now scheduled to be launched in December, and its total budget has been raised to $ 9.7 billion. Another space observatory that NASA is currently working on, the Nancy Grace Roman Space Telescope (formerly called WFIRST), has also struggled with rising costs, so much so that the Trump administration has tried to cancel the project. Both telescopes were considered missions with the highest priority in previous decades of studies.

The committee that wrote the ten-year report claims that it makes these recommendations with those lessons learned. First, he argues that many of the technologies needed for JWST to work simply did not exist when the telescope was designed. "Making that invention and technological maturation and testing and engineering - it took a long time," says Stassun. "And when things last a long time, they're expensive." He hopes that astronomers will not be so amazed by the technologies they will have to create, starting with the big telescope projects.

Stassun also says the phased development approach will allow mission planners to check in from time to time to see how things are going. If one mission gets out of control, then it can be interrupted or changed while the others remain in development. In this way, there is no mission to absorb all the energy - and money - in the room, as JWST did. Most of NASA's astrophysics budget has been dedicated to JWST in its most important years of development, making it more difficult for small projects to obtain significant funding.

It could be a challenging sale to Congress, which ultimately determines NASA's budget and has been critical of JWST's ballooning costs. But scientists are optimistic. NASA's science budget has grown in recent decades, and Gaudi believes that humans will be inspired by what these future telescopes could tell us. "I came to Congress, and the American people said, 'Look, this is fantastic science that can answer the huge questions that will inspire future generations,'" Gaudi said. "And it requires a modest increase in the budget for the development of astrophysics. I think we can do that. "

"NASA is looking forward to reviewing the recommendations in detail and appreciates the steering committee and panels for their dedicated work in providing this report," the space agency said in a statement after the report was released. "The survey will inform a new compelling chapter in astrophysics."

The decade-long survey calls for more than just building telescopes. The authors want to ensure that the people who work on these projects are protected. The report calls for a diversity and inclusion strategy for these missions, one that would make harassment and discrimination a form of misconduct - a move that could end his career. And they also want the mission teams to be more aware of how their work affects indigenous communities and the environment. For example, the authors suggest that astronomers adopt long-distance distance conferences to reduce their carbon emissions from the flight.

There is still a long way to turn these dreams into reality. But for now, astronomers are excited about what looks like a bright future. "We are on the threshold of a new golden age of discovery, both on earth and in space: could we find evidence for life on another planet?" says Hammel. "This report - true to its name - shows solid ways to answer this question, and we can be the generation that answers it." @via theverge .