On April 18th, 2018, a cloudless blue-sky day, our hearts pounded with anticipation during the last few seconds of the countdown for a Space-X Falcon 9 rocket, which was ready to fire and lift off from a launchpad at Cape Canaveral. Sitting inside the rocket’s nose cone was a small payload known as TESS - the Transiting Exoplanet Survey Satellite, a NASA mission led by scientists and engineers at the Massachusetts Institute of Technology. More than a decade of work had gone into the satellite, and now it was time to send it to space.
TESS is a planet-hunting telescope.
It will survey large swaths of sky looking for worlds orbiting bright stars not too far from Earth. The satellite is the brainchild of principal investigator George Ricker and his colleagues, who, more than a decade ago, tried to use guide cameras from the High- Energy Transit Explorer (HETE-2) to detect slight dips in brightness that occur when a planet moves in front of the face of its star and briefly blocks some of the star’s light.
The mini-eclipse that results is what we call a planetary transit, and of the 3,700 confirmed exoplanets detected to date, many have been discovered using this technique of looking for dips.
Whether such worlds even exist is a question people have wondered about for ages, but only for the past few decades have we had the tools to search for planets beyond our Solar System. The first discoveries came from ground-based telescopes, and then space-based satellites. But it was the Kepler Space Telescope - the first true planet hunter - that solidified the existence of worlds well beyond the Solar System. Prior to its 2009 launch, we knew of only a few hundred exoplanets. After Kepler, we knew of thousands.
TESS will follow in Kepler’s footsteps, scrutinizing upwards of 200,000 nearby stars for signs of planets - another step in the search for a habitable world beyond Earth.
This story was originally published on American Scientist. We are republishing a lightly edited version to SkyFeed in light of interest on the subject. Source: Seager, Sara. "What's Next for Finding Other Earth-like Worlds?" American Scientist. Sept-Oct. 2018. Web magazine.