NASA’s Transiting Exoplanet Survey Satellite (TESS) has taken its first wide-sky image and confirmed the sighting of its first exoplanet. The exoplanet hunt was officially launched in April 2018.
An exoplanet or extra solar planet is a planet outside the Sun’s solar system.
The “first light” image, as the first useful image is called, was taken on August 7 with all four of the telescope’s cameras and released on September 17. It shows a field of stars and two of the Milky Way’s satellite galaxies, the Large and Small Magellanic clouds. The telescope’s light detector was saturated by a few extremely bright stars, creating streaks of light across the whole image.
TESS spotted the new planet, named Pi Men c, crossing in front of its bright sun-like star 60 light-years from Earth and blocking a bit of the starlight. Data collected from July 25 to August 22 revealed that the planet is 2.14 times Earth’s radius and orbits its star every 6.27 days.
The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such. However, the first scientific detection of an exoplanet was in 1988 but it wasn’t confirmed to be an exoplanet until later in 2012. The researchers found previously unnoticed evidence of the planet in data from the HARPS spectrograph and the Anglo-Australian Planet Search, which have monitored the star, Pi Mensae, over the past 20 years. Those observations show the nature of the planet’s gravity that tug on the star which led the researchers to determine that the planet’s mass is about 4.8 times that of the Earth. Those telescopes had previously also revealed another planet which was the size of Jupiter, orbiting Pi Mensae every 5.7 years.
Pi Men c’s size and mass suggest it may have lots of water. It probably has a core made of iron and rock, surrounded by an ocean or atmosphere of lighter materials like water, methane, hydrogen and helium.