Smallest exoplanet EVER discovered by NASA’s TESS mission is found just 35 light years away — with two Earth-like worlds also spotted
- Dubbed L 98-59b the little world is smaller than the Earth but bigger than Mars
- None of the three newly-found planets are in the habitable zone of their host star
- NASA’s Transiting Exoplanet Survey Satellite looks for dips in star brightness
- These temporary lulls can signify the passage of an exoplanet in front of the star
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.
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.
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 Futurism.
‘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 The Astronomical Journal.