Scientists believe that if NASA really wants to seriously search for life beyond Earth, the Agency will require new large space telescope, one that will be able to directly photograph planets outside our Solar system. Such technologies currently do not exist — only their raw version. But astronomers say that this is our best chance to find another Land where you can live biological organisms.
This concept of the mission was the top recommendation in the new report, compiled by members of the National academies of Sciences, engineering and medicine. The Academy was tasked by Congress to develop the best strategy for the study and research of exoplanets — worlds beyond our Solar system. And after gathering information from experts in this field, the National Academy presented seven recommendations, among which at the top of the list — a new telescope.
What astronomers plan to do with the space?
Of course, nobody will force execution of the query, given the harsh reality faced by NASA when trying to build their new large space Observatory, the space telescope James Webb or JWST. It was originally planned that it will cost $ 1 billion and launched in 2007. But last June it became known that the project had been spent to 9.66 billion dollars, and the telescope will be launched in the best case scenario in 2021. A new telescope should be built to search for alien life, will also include new technologies that have not even been tested in space. It can be even more complicated and expensive than even JWST.
However, in this report, the authors did not think about the possible financial constraints. “We specifically did not take into account cost, schedule, or any such things,” said Scott Gaudi, Professor of astronomy at the Ohio state University, who participated in creating the report, as well as working on the concept of the mission space telescope HabEx. “It’s just a consensus that feels ekzoplanetoy community, and the most important things you need to do to answer the research problem”.
The goal is relatively simple. The first agenda of the report sets out what we need to understand how the planets formed. When stars are born, they are usually formed in a swirling disc of gas and dust, and then in the same disk be a separate planet. How do these discs change from a simple gas in a full-fledged planet?
The second goal attracts everyone on this planet: is there another planet in the type of Land on which life can be? And here we need a new telescope. Direct images of planets could tell a lot about how they look and what’s in their atmospheres. The gas that surrounds the planet, may contain important clues about what is underneath the surface. For example, gases associated with life, like oxygen and methane would be a strong signal for the presence of biological organisms on a distant planet. “We could conduct a census of the atmospheric composition of a large sample of earth-like planets,” says Laura Kreidberg, ekzoplaneta astronomer of Harvard University.
How to see an exoplanet?
In our days astronomers find extrasolar planets by using clever methods, but not directly. The easiest way to see remote worlds and watch as they pass in front of its parent star, i.e. transit. These transitions slightly darken the light of the star, causing a slight dimming in brightness that can be measured from the Ground. The spacecraft NASA’s TESS that are orbiting the Earth, looking for planets in this way, the telescope and the future James Webb will also be. Another method is to observe how the planet’s gravity affects the parent star. Despite its small size, planets may cause a slight rocking motion of the stars, thereby giving their presence.
However, a direct image of extrasolar planets is a monumental task, especially the size of the Earth. These planets are very close to their parent stars and drowns out the starlight. A separate earth-like planet is 10 billion times fainter than the star which is in orbit. Therefore, to directly to shoot them, scientists need to equip future space telescopes with special instruments that block or reduce the light of the stars.
Fortunately, astronomers are working on it. One of the concepts that are considered to use, the coronagraph optical tool that can be attached to the telescope to suppress the starlight with mirrors, so it will be easier to see the planets that hide close by. Telescopes on Earth and in space was fitted with coronagraphy to study the Sun, but in space, similar high-contrast instruments to block the light of distant stars to be fully tested. NASA currently plans to demonstrate this technology for the first time on one of the future space telescope — WFIRST. This step also recommended by the National academies.
In addition to the coronagraph, there is another interesting option. Astronomers wanted to try something known as “star shadow”. This is a large flower structure that flies in front of the telescope, blocking the light from the stars, “casting a shadow”. “Not a single ray of starlight does not fall into the telescope, only light on the planet,” says Gaudi.
The only problem is that this technology is quite complex. The flower will have to swim 100,000 km from the telescope in space and its position must be precisely controlled to normally block the light of distant stars. And as a coronagraph, the stellar shadow (or started) is still very crude technology. In addition, a proposed telescope with which astronomers want to observe extrasolar planets, will be large and heavy. For example, the concept LUVOIR mirror will be more than even JWST.
Any projects of telescopes with the possibility of direct observation of planets would cost billions of dollars, and such costs will not be easy to accept even the Congress, given the delays in implementation and extension of the JWST budget. But astronomers are optimistic about the future, believing that once the project is yet to be implemented. This is an ambitious but achievable goal, especially in comparison with already achieved — to take the same landing men on the moon.
Gaudi also understands the difficulties that stand in the way of this project. But this report merely reflects what he hopes to achieve ekzoplanetoy community.
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The search for alien life will require a new space telescope
Ilya Hel