“Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying.” -Arthur Clarke
Some of NASA’s top scientists held a public panel at the headquarters in Washington, D.C. earlier this week (July 14). They discussed the possibility of extraterrestrial life and how NASA’s current and future technology used for studying exoplanets could aid in its detection; an announcement that could possibly come even within the next twenty years.
The first confirmed exoplanet was discovered in 1988. There have since been thousands of candidate exoplanets over the years with over 1800 confirmations, though there are likely billions across the Universe. Data from telescopes like NASA’s Kepler and ESO’s Very Large Telescope have allowed astronomers to discern information about a planet’s composition, atmosphere, potential habitability, and other characteristics as the planet transits the star.
"What we didn't know five years ago is that perhaps 10 to 20 percent of stars around us have Earth-size planets in the habitable zone," Space Telescope Science Institute director Matt Mountain stated. "It's within our grasp to pull off a discovery that will change the world forever. It is going to take a continuing partnership between NASA, science, technology, the U.S. and international space endeavors, as exemplified by the James Webb Space Telescope (JWST), to build the next bridge to humanity's future."
Life, as we know it, requires the presence of liquid water. While it is entirely possible that there are other lifeforms out there that don’t need water, it makes the most sense to search for what we know. In addition to a planet’s distance from its star, atmospheric conditions and planetary composition also impact the probability that liquid water could exist. Future missions will search for chemical indicators of life on exoplanets, including water and carbon dioxide.
"This technology we are using to explore exoplanets is real," said John Grunsfeld, Associate Administrator for NASA's Science Mission Directorate and an astronaut who was part of five Space Shuttle mission. "The James Webb Space Telescope and the next advances are happening now. These are not dreams— this is what we do at NASA."
The JWST is currently scheduled to launch in 2018 with an expected mission life of 5-10 years. It will orbit Earth from a distance four times farther than the average distance of the moon, exploring the earliest galaxies in the Universe and studying chemical signals from exoplanet candidates at near- and mid-infrared wavelengths. In addition to the current list of candidate exoplanets, thousands more will be added by Transiting Exoplanet Survey Satellite (TESS) which will be able to study stars 30-100 times brighter than those studied by Kepler. TESS is expected to launch in 2017 for its 2 year mission.
"Just imagine the moment when we find potential signatures of life,” Mountain said. “Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over— the possibility we're no longer alone in the universe."
Check out the full panel discussion here: