Does life exist beyond our solar system?
That’s the question NASA hopes to answer with a satellite called TESS (Transiting Exoplanet Survey Satellite), which was launched last month from Cape Canaveral, Florida.
The actual mission for TESS will last about two years. In that time, the satellite will survey 26 different sectors, exploring what is thought to be thousands of exoplanets we’ve yet to discover. To do that, TESS will use four wide-field cameras. During its first year, the satellite will cover 13 sectors of the southern sky, and it will cover another 13 sectors of the northern sky during the second year of its mission. When all is said and done, TESS will have covered about 85% of the sky.
Specifically, the satellite will be looking for something called a “transit.” This phenomenon occurs whenever a planet crosses in front of its star, which causes a change in the star’s brightness from the perspective of an observer. To date, almost 2,900 exoplanets have been found using the transit method.
TESS isn’t the first satellite launched into space for this purpose. NASA’s Kepler spacecraft completed a similar mission, and it found over 2,600 exoplanets. The difference between the missions of the two satellites is the distance at which the exoplanets have/will be discovered. Kepler focuses on exoplanets that are 300-3,000 lightyears away from Earth. TESS is going to focus on exoplanets that are much closer—30 to 300 light years from Earth.
Once an exoplanet has been discovered, researchers will use spectroscopy to study the specifics of the planet. Spectroscopy measures the absorption and emission of light. This can then be used to determine a planet’s atmospheric conditions, mass and density. All of that information can then be used to determine the planets’ potential to sustain life.
“The targets TESS finds are going to be fantastic subjects for research for decades to come,” said Stephen Rinehart, TESS project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “It’s the beginning of a new era of exoplanet research.”