NASA’s Transiting Exoplanet Survey Satellite (TESS) has achieved a first: detecting a Jupiter-like world orbiting another star through gravitational microlensing. This technique, which leverages the warping of spacetime predicted by Einstein's general relativity, allowed the spacecraft to spot the hidden planet in archived data. The discovery marks a new capability for the exoplanet hunter.
The method works when a foreground star’s gravity bends and magnifies light from a background star, revealing an unseen planet. Unlike TESS’s primary transit method—which watches for dips in starlight as a planet crosses in front of its star—microlensing can find worlds that do not transit. The newfound planet shares characteristics with Jupiter, though precise mass and orbital details remain under analysis.
TESS collected the light curve data during its primary mission, but the microlensing signal was only recently identified by sifting through archived observations. No specific discovery date or mission phase was mentioned. The finding demonstrates the value of mining older datasets for overlooked events.
This breakthrough expands TESS’s scientific scope, proving it can detect planets via an entirely different phenomenon. The technique could uncover rogue planets or distant worlds in wide orbits that evade traditional methods, potentially doubling the variety of planets the satellite will find.
While powerful, gravitational microlensing events are rare and non-repeatable, limiting follow-up observations. Researchers caution that the planet's exact properties will require further study, possibly by ground-based telescopes, to confirm the initial findings.