US scientists describe their research plan for life in the universe – Quartz

The discovery of many potentially habitable planets beyond the solar system and a growing understanding of the diversity of life on Earth offer NASA an opportunity to advance the field of astrobiology, according to a new report from the National Academy of Sciences.

A group of experts bringing together researchers, chaired by Barbara Sherwood Lollar of the University of Toronto, drafted the report at the request of the US Congress. He had asked in a 2017 law the development of a "strategy for astrobiology" in order to give priority to "the search for the origin of life". , evolution, distribution and future in the universe. "

The 196-page report does not offer easy access to extraterrestrial technologies, but the steady pace of scientific advances it documents suggests an increasingly sophisticated understanding of what we know – and do not know – about biology on our planet and beyond.

Indeed, the newly acquired knowledge is the beginning of a wave: only the Viking mission of the 1970s rigorously sought the traces of life on other planets and the first new mission of NASA to do so, the Europa lander , has been conceived. In the last four years alone, scientists have used data collected by space probes on Mars to discover traces of surface water, nutrients and organic molecules, and methane in the atmosphere, which vary with seasons.

This does not mean that life now exists on Mars, but it does contribute to the understanding of astrobiology as a discipline that examines physical and chemical processes over time to determine if the conditions of life have existed. or could be in the future.

Much of the work on astrobiology is centered on the Earth; This is the only place where we know that life exists. It is therefore our guinea pig that detects life at a distance. The Galileo spacecraft found signs of life on our planet in 1990.

The report pointed out that recent discoveries of life on Earth without the energy of the sun, at the bottom of the ocean or the ground, should inform what we are looking for on other worlds. Scientists are deepening their understanding of habitability beyond a binary behavior and on a spectrum, which may seem trivial, but previous research relied on blunt instruments and crude assumptions about extraterrestrial life, starting with the idea that it would appear on the surface.

Nevertheless, a key problem is that scientists still do not understand exactly how life has occurred on Earth, making it difficult to know what to look for in other worlds. Missions like Hayabusa 2 in Japan and NASA's OSIRIS-REx plan to return samples of carbon-rich asteroids to Earth over the next five years to better understand the early solar system and the development of our own planet.

The most important development highlighted by scientists is by far the advance of the Kepler probe in the identification of planets beyond the solar system. The number of identified exoplanets has doubled since 2015, "enough to justify new steps towards the discovery of life on exoplanets". This implies – unsurprisingly here – to follow up NASA's James Webb space telescope project, which will learn important features on distant planets spotted by NASA's latest observatory, TESS.

Technology also plays a role. There are prosaic problems to be solved, such as the difficulty of creating exercises that penetrate well under low gravity to penetrate the surface of distant planets or tools to identify weak biosignatures in extreme conditions without generating false positives. But there are promising developments, such as smaller, more powerful satellites and data science techniques that can be used to explore the huge amounts of data collected by NASA observatories. The report, like most space-related companies, makes the most of the potential of public-private partnerships to expand data collection.

Some thinkers who rely on the Fermi paradox believe that the probability of life beyond the Earth is extremely low. But this report reminds us that the assumptions we make about life beyond our own world are changing rapidly – and that investigating them empirically can also reveal truths about ourselves.