If Earth has a twin there, NASA ought to find it.
This is what we take away from a report once a decade that sets out the priorities of astronomy for the coming decade. To find such exoplanets similar to those of Earth, NASA would have to build a large fantasy space telescope, says the report.
Every 10 years, the National Academies of Sciences, Engineering, and Medicine advise government agencies, such as NASA and the National Science Foundation, as to what research objectives astronomers should prioritize in the coming decade, Space.com reported. The Board released its most recent report on Thursday (November). 4) And highlighted three major research priorities: to better understand the nature of black holes and neutron stars; to investigate how galaxies form and evolve, and to identify "habitable earthlike worlds" and biochemical signatures of life in other planetary systems.
On this last point, Fiona Harrison, a Caltech astrophysicist who co-chaired the committee, told NPR, "The most amazing scientific opportunity ahead of us in the coming decades is the possibility that we can find life on another planet orbiting a star in our galactic neighborhood."
The committee recommended that to find such planets, NASA build a telescope that eclipses the Hubble Space Telescope and is equipped with infrared, optical, and ultraviolet sensors. The telescope would also carry a chronograph, a telescopic attachment designed to block out direct light from a star so that nearby objects can be seen, Axios reported; otherwise, faint exoplanets might be obscured by the light of a neighboring star that shines 10 billion times brighter than they do.
According to Axios, the construction of the telescope would cost around $11 billion and is expected (ideally) to be launched in the early 2040s.
With such a telescope, "you're not going to see continents on the surface of the planets … we'll see distinct little dots," Bruce Macintosh, an astrophysicist at Stanford and a member of the committee, told The Atlantic. Then, in analyzing the light reflected from the exoplanet, the scientists were able to determine the chemical composition of its atmosphere. Atmospheric evidence of oxygen, methane, and water could hint at the presence of life on the planet, although astronomers would need to rule out other explanations for these chemical signatures, such as volcanic activity.
"When we see the first hint of life out there in the universe and see the fingerprints of life in a distant world, humanity's place in the universe is fundamentally changed," John O'Meara, committee member and chief scientist at the W. M. Keck Observatory, told Axios.
A decade ago, such a mission would have been considered "a little bit pie in the sky," Jonathan Fortney, a planetary scientist at the University of California, Santa Cruz and one of the members of the committee, told The Atlantic. To date, however, scientists have identified more than 4,500 exoplanets, of which about 160 are rocky, such as Earth.
With the ability to discover and analyze the atmospheres of far-off worlds, "we have a route to being able to start to answer the question, 'Are we alone?'" Rachel Osten, an astronomer with the Space Telescope Science Institute who served on the committee, told NPR.