NASA's planet-hunting satellite will remain in action for at least another two years, so hopefully, this first image is really just the first of many.
Although the discovery has yet to be reviewed by other scientists to validate it, the preliminary analysis suggests that Pi Mensae c, the newly found exoplanet, is around four times as massive as Earth and contains a substantial portion of lighter materials - such as water, methane, hydrogen, and helium - in addition to a rocky/iron core. TESS will observe the transit phases of exoplanets, which happens when an orbiting planet passes in front of its star, reducing its luminosity and allowing better observation.
As for the prospects of life? A year on this exoplanet (one full orbit around its star) lasts just 6.27 days. From a satellite's perspective, this results in a decrease in the star's brightness. "Such stars enable precise measurements of that planet's mass and radius", the authors write in their paper.
TESS acquired the images using all four cameras during a 30-min period on August 7, 2018.
That's the dip TESS is looking for. Astronomers published a paper about the new discovery in the database of preprints arXiv.org.
"This swath of the sky's southern hemisphere includes more than a dozen stars we know have transiting planets based on previous studies from ground observatories", said George Ricker, TESS principal investigator.
As for the other planet, it is described as a bit larger than Earth with an orbit around its star that takes a mere 11 hours.
Meanwhile, TESS is busy sweeping the skies for more exciting discoveries. Together, the cameras let TESS scan a narrow strip of the sky stretching from the polar region to the equator.
TESS' current mission is set for a length of two years, during which it will cover 85 percent of the sky. I mentioned the survey is expected to find 20,000 exoplanets, but a decent chunk of them will be closer to Earth-sized.
Somewhere among these grains of celestial sugar and powder puffs of cloudy light there is a planet, perhaps many planets, perhaps even Earth 2.0, as astronomers sometimes call the object of their dreams - a terrestrial look-alike to our own world, a "Goldilocks" place not too hot nor too cold, where Darwin's dice might have come up sevens. NASA stated that TESS, the "first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances". Slap the two data points together we learn what the density of the exoplanet is.