Washington DC, Gatra.com- If Earth has a twin somewhere out there, NASA has to find it. That’s the conclusion of a ten-year report that sets out astronomical priorities for the next decade. Live Science, 06/11.
To find exoplanets like Earth, NASA will have to build a new, large and sophisticated space telescope, the report says.
Every 10 years, the National Academies of Science, Engineering, and Medicine advise government agencies, such as NASA and the National Science Foundation, on what research goals astronomers should prioritize in the next decade, Space.com report.
The advisors released their latest report Thursday (November 4) and highlighted three main research priorities: to better understand the nature of black holes and neutron stars; to investigate how galaxies form and evolve; and to identify “inhabitable Earth-like worlds” and biochemical signs of life on other planetary systems.
On this last point, Fiona Harrison, the Caltech astrophysicist who chairs the committee, told NPR, “The most amazing scientific opportunity before us in the next few decades is the possibility that we may find life on other planets orbiting stars in a galactic environment.”
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The committee recommended that, to find such a planet, NASA should build a telescope that dwarfs the Hubble Space Telescope and is equipped with infrared, optical, and ultraviolet sensors. The telescope will also carry a coronagraph, a telescopic attachment designed to block direct light from the star so that nearby objects can be seen. Axios report; otherwise, dim exoplanets may be obscured by the light of neighboring stars that shine 10 billion times brighter than them.
The telescope will cost around US$11 billion to build and (ideally) launch in the early 2040s, Axios report.
With a telescope like that, “you wouldn’t see the continents on the planet’s surface … we would see different little dots,” Bruce Macintosh, an astrophysicist at Stanford and a member of the committee, told The Atlantic. Then, by analyzing the light reflected from the exoplanet, scientists can figure out the chemical composition of its atmosphere.
Evidence of an atmosphere of oxygen, methane, and water could hint at the existence of life on the planet, though astronomers need to rule out other explanations for these chemical signatures, such as volcanic activity.
“When we look at the first hints of life in the universe and see traces of life on distant worlds, humanity’s place in the universe changes fundamentally,” John O’Meara, committee member and chief scientist at the WM Keck Observatory told Axios.
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A decade ago, such a mission would have been considered “a little cake in the sky,” Jonathan Fortney, a planetary scientist at the University of California, Santa Cruz and one of the committee members, told The Atlantic. But to date, scientists have identified more than 4,500 exoplanets, about 160 of which are rocky, like Earth.
With the ability to find and analyze the atmospheres of distant worlds, “we have a route where we can begin to answer the question, ‘Are we alone?'” Rachel Osten, astronomer from Space Telescope Science Institute who served on the committee, said NPR.
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