Check NASA’s exoplanet catalogue and you’ll see that just shy of 5,000 exoplanets have been discovered and confirmed so far. Expect that figure to grow massively in the next few years as data from NASA’s exoplanet-spotting spacecraft reveals a staggering haul of alien worlds, according to a new study.
A paper published on the pre-print service arXiv reveals that NASA’s $287 million Transiting Exoplanet Survey Satellite (TESS) has discovered about 5,000 planets and planet candidates in its first three and a half years of observations.
An exoplanet is a planet orbiting another star, so beyond our Solar System.
Launched in mid-2018 by a SpaceX Falcon 9 rocket, the TESS spacecraft quickly completed its first mission; to identify exoplanets orbiting bright stars in the northern sky within 300 light years of Earth using its wide-field telescope.
In mid-2020 it began its first extended mission—to observe exoplanets around the ecliptic plane of the Solar System—and in September this year it will begin a second extended mission to doo the same for the southern sky.
What more it it going to find? Quite a lot, according to the paper’s authors, who used simulations of detectable planets to calculate that TESS will gradually reveal many thousands more exoplanets—and not just from observations it’s yet to make.
The paper estimates that from data already collected and observations it’s scheduled to make we can expect astronomers to eventually identify about:
- 4,719 exoplanets from its “prime mission” (2018-2020)
- 3,707 exoplanets from its first extended mission (2022-2024)
- 4,093 exoplanets from its second extended mission (2022-2024)
That’s a staggering total of 12,519 exoplanets!
By the end of its second extended mission TESS will be in its seventh year, by which time it will have observed almost the entire sky.
The authors calculate that by the end of its three missions its haul of exoplanets will reveal that G-type stars—stars like our Sun—are the most common exoplanet hosts. And while most of the exoplanets it finds will be giant planets, as the mission wears on it will find more and more smaller and smaller planets “including dozens similar to Earth’s size,” reads the paper.
TESS will also find hot Neptunes, giant planets around red dwarf stars and planets that take more than 500 days to orbit their stars, according to the authors.
Exactly those types of exoplanets were missing from the data provided by NASA’s $600 million Kepler Space Telescope, a keystone mission for exoplanet science that launched in 2009 and observed almost 200,000 stars in a tiny patch of sky between 2009 and 2018.
Kepler looked for planets transiting across their hosts stars, identifying a staggering 2,392 exoplanets before suffering a technical defect. However, Kepler did something incredible—it showed us all that every star in the night sky, on average, has at least one planet.
TESS now looks set to further revolutionize how we think about exoplanets—and life—in the galaxy beyond the Solar System.
Wishing you clear skies and wide eyes.