ANTOFAGASTA, Chile — A rocky waterworld just 35 light years from Earth may have all the ingredients which make it possible for aliens to live there, a new study reveals.
Researchers with the European Space Observatory (ESO) say this exoplanet is just the right distance from a cool and bright star, so water is capable of flowing on the surface. Astronomers spotted this world in the southern constellation Volans. It lies in the “Goldilocks” — or habitable — zone of its solar system, where scientists believe life can survive.
“We have hints of the presence of a terrestrial planet in the habitable zone of this system,” says lead author Dr. Olivier Demangeon from the University of Porto in Portugal in a media release.
A second unconfirmed planet lies further from the star, called L 98-59, and it too may support life as we know it.
“The planet in the habitable zone may have an atmosphere that could protect and support life,” adds co-author Professor Maria Osorio from the Centre for Astrobiology in Madrid.
A solar system very similar to our own
Three inner planets in the system have been spotted previously by scientists, but two are mainly dry and barren worlds. The third planet is also an ocean world with up to 30 percent water however, it appears to be too warm for organisms to exist.
The discovery is an important step in the quest to find extraterrestrial life in the universe. The findings come from an analysis of data collected by the European Space Observatory’s Very Large Telescope (VLT) in Chile. It found the exoplanets of this system resemble Earth, Venus, Mercury, and Mars.
The detection of life will depend on the ability of the team to study each planet’s atmosphere. Current telescopes are not large enough to accomplish this. The European Space Agency’s ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) will be doing so by the end of the decade.
The L 98-59 system is expected to be among the first in its sights. It has rocky planets like Earth and Venus that are close enough to the star to be warm. Scientists believe the three inner planets also have water in their atmospheres. The fourth — and possible fifth — planets, however, have it on their surfaces.
How did scientists find these planets?
The study in the journal Astronomy & Astrophysics represents a technical breakthrough in space exploration. Study authors established that the innermost planet has just half the mass of Venus, the lightest ever measured using the radial velocity technique. It calculates the wobble of a star caused by the tiny gravitational tug of orbiting planets.
Astronomers spotted the first three of L 98-59’s planets in 2019 using NASA’s TESS (Transiting Exoplanet Survey Satellite). The device 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 ESPRESSO (Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations) instrument on the VLT enabled detection of the other planets as well as determining their sizes.
“If we want to know what a planet is made of, the minimum we need is its mass and its radius,” says Dr. Demangeon.
New space probes may help find life in L 98-59
The team plans to further study the system with the forthcoming James Webb Space Telescope (JWST). ESO’s Extremely Large Telescope (ELT), under construction in the Chilean Atacama Desert and set to start observations in 2027, will also be ideal for this research.
“The HIRES instrument on the ELT may have the power to study the atmospheres of some of the planets in the L 98-59 system, thus complementing the JWST from the ground,” Prof. Osorio explains.
Astronomers have discovered almost 5,000 exoplanets so far. Estimates show that the Milky Way may contain as many as 100,000 million exoplanets alone.
“This system announces what is to come,” Dr. Demangeon concludes. “We, as a society, have been chasing terrestrial planets since the birth of astronomy and now we are finally getting closer and closer to the detection of a terrestrial planet in the habitable zone of its star, of which we could study the atmosphere.”
South West News Service writer Mark Waghorn contributed to this report.