https://www.nasa.gov/feature/goddard/2017/spanning-disciplines-in-the-search-for-life-beyond-earth
The search for life beyond Earth is riding a surge of creativity and innovation. Following a gold rush of exoplanet discovery over
the past two decades, it is time to tackle the next step: determining which of the known exoplanets are proper candidates for life.
Scientists from NASA and two universities presented new results dedicated to this task in fields spanning astrophysics, Earth science,
heliophysics and planetary science — demonstrating how a cross-disciplinary approach is essential to finding life on other worlds — at
the fall meeting of the American Geophysical Union on Dec. 13, 2017, in New Orleans, Louisiana.
“The potentially habitable real estate in the universe has greatly expanded,” said Giada Arney, an astrobiologist at NASA’s Goddard Space
Flight Center in Greenbelt, Maryland. “We now know of thousands of exoplanets, but what we know about them is limited because we can’t
yet see them directly.”
Currently, scientists mostly rely on indirect methods to identify and study exoplanets; such methods can tell them whether a planet is
Earth-like or how close it is to its parent star. But this isn’t yet enough to say whether a planet is truly habitable, or suitable for
life — for this, scientists must ultimately be able to observe exoplanets directly.
Direct-imaging instrument and mission designs are underway, but in the meantime, Arney explained, scientists are making progress with tools
already at their disposal. They are building computational models to simulate what habitable planets might look like and how they would
interact with their parent stars. To validate their models, they are looking to planets within our own solar system, as analogs for
the exoplanets we may one day discover. This, of course, includes Earth itself — the planet we know best, and the only one we know
of yet that is habitable.