The newly-discovered world — dubbed L 98-59b — is smaller than the Earth but still bigger than Mars and orbits around a cool, bright star only 35 light years from us.
Alongside this record-breaking discovery, TESS has also spotted two other worlds in the system that are slightly larger than Earth.
Unfortunately, all three worlds orbit too close to their star to have liquid water on their surfaces — making finding alien life there unlikely.
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NASA’s exoplanet-hunting TESS space telescope has found its tiniest planet to date. The newly-discovered world — dubbed L 98-59b — is smaller than the Earth but still bigger than Mars and orbits around a cool, bright star only 35 light years from us (artist’s impression)
However, researchers think that the three planets might have atmospheres that are similar to that found on Venus, although further studies will need to confirm this.
The three planets are the latest coup for NASA’s Transiting Exoplanet Survey Satellite (TESS), a space telescope that lies in a high-Earth orbit.
TESS works by studying light from distant stars and looking for the regular dips in apparent brightness caused by an exoplanet ‘transiting’ in front of the star.
‘The discovery is a great engineering and scientific accomplishment for TESS,’ NASA astrophysicist Veselin Kostov of the Goddard Space Flight Center told
‘For atmospheric studies of small planets, you need short orbits around bright stars, but such planets are difficult to detect.’
The other two worlds that TESS has discovered in this star system — which researchers have dubbed L 98-59c and L 98-59d — are around 1.4 and 1.6 times the size of the Earth, respectively.
According to NASA, none of the three worlds are found within their star’s habitable zone — meaning that life-supporting liquid water will not exist on their surfaces.
However, the planets do all lie within the so-called ‘Venus zone’, the region around a star in which a planet with an Earth-like atmosphere would be pushed into a runaway greenhouse situation that would result in a Venus-like atmosphere developing.
Studies to determine if the planets have atmospheres and, if so, what they are made of will be required to see if this has indeed been the case.
Alongside this record-breaking discovery, TESS has also spotted two other worlds in the system that are slightly larger than Earth (pictured, in an artist’s impression)
The three planets are the latest coup for NASA’s Transiting Exoplanet Survey Satellite, a space telescope (pictured in this artist’s impression) that lies in a high-Earth orbit
In addition, there is the potential for TESS to detect further planets in the same system when it conducts its next four planned observations of the star.
‘This system has the potential for fascinating future studies,’ Dr Kostov said.
The full findings of the study were published in
WHAT IS THE TESS SPACECRAFT?
NASA’s new ‘planet hunter,’ set to be Kepler’s successor, is equipped with four cameras that will allow it to view 85 per cent of the entire sky, as it searches exoplanets orbiting stars less than 300 light-years away.
By studying objects much brighter than the Kepler targets, it’s hoped TESS could uncover new clues on the possibility of life elsewhere in the universe.
Its four wide-field cameras will view the sky in 26 segments, each of which it will observe one by one.
In its first year of operation, it will map the 13 sectors that make up the southern sky.
Then, the following year, it will scour the northern sectors.
‘We learned from Kepler that there are more planets than stars in our sky, and now TESS will open our eyes to the variety of planets around some of the closest stars,’ said Paul Hertz, Astrophysics Division director at NASA’s Headquarters.
‘TESS will cast a wider net than ever before for enigmatic worlds whose properties can be probed by NASA’s upcoming James Webb Space Telescope and other missions.’
Tess is 5 feet (1.5 meters) wide and is shorter than most adults.
The observatory is 4 feet across (1.2 meters), not counting the solar wings, which are folded for launch, and weighs just 800 pounds (362 kilograms).
NASA says it’s somewhere between the size of a refrigerator and a stacked washer and dryer.
Tess will aim for a unique elongated orbit that passes within 45,000 miles of Earth on one end and as far away as the orbit of the moon on the other end.
It will take Tess two weeks to circle Earth.