What are the two planets discovered that are very similar to Earth and where life could exist

Thanks to new, more powerful ground-based and space-based telescopes, in recent years space agencies and astronomers have been busy investigating the potentially habitable worlds of nearby stars. These planets, called exoplanets because they are outside our Solar System, have many times the same mass as Earth and a distance similar to what we have from their star.

Now, an international team of researchers, led by scientists from the Instituto de Astrofísica de Canarias (IAC), has made public the discovery of two planets with a mass similar to Earth in orbit around the star GJ 1002, a red dwarf not too far from Earth. Solar system. Both worlds are in the habitable zone of the star, that is, at the correct distance for liquid water to exist on their surfaces.

“Nature seems hell-bent on showing us that Earth-like planets are very common. With these two we already know 7 in planetary systems quite close to the Sun”, explained Alejandro Suárez Mascareño, from the IAC and first author of the study published in the journal Astronomy & Astrophysics.

The two new planets, GJ 1002b and GJ 1002c, are about 16 light-years away. Both have masses very similar to our own world; and the first, the innermost, takes 10 days to complete an orbit around its star; while the second one, a little further from it, needs a little more than 21 days. These worlds are in the habitable zone of the star, that is to say, at the correct distance so that liquid water can exist on their surfaces.

The proximity of the star to our Solar System implies that the two planets, especially GJ 1002c, are excellent candidates for characterizing their atmospheres based on their reflected light or thermal emission.

“The future ANDES spectrograph for the ESO ELT telescope in which the IAC participates could study the presence of oxygen in the atmosphere of GJ 1002c” points out Jonay I. González Hernández, IAC researcher and co-author of the article. In addition, both planets meet the necessary characteristics to be targets of the future LIFE mission, which is currently under study.

The discovery was made during a collaboration between the consortia of the two instruments ESPRESSO and CARMENES. GJ 1002 was observed by CARMENES between 2017 and 2019, and by ESPRESSO between 2019 and 2021. “Due to its low temperature, the visible light of GJ 1002 is too weak to measure its velocity variations with most spectrographs,” he specified. Ignasi Ribas, researcher at the Institute of Space Sciences (ICE-CSIC) and director of the Institut d’Estudis Espacials de Catalunya (IEEC).

CARMENES has a sensitivity over a wide range of near-infrared wavelengths that is superior to that of other spectrographs designed to detect variations in the speeds of stars, and this allowed it to study GJ 1002, from the observatory’s 3.5-m telescope. of Calar Alto.

The combination of ESPRESSO and the light-gathering power of the VLT 8m telescopes at ESO, allowed measurements to be made with a precision of only 30 cm/sec, which cannot be achieved with any other instrument in the world. The planets emit very weak light, so detecting them required 139 spectroscopic observations (deep space radiation measurements) taken between 2017 and 2021.

“Either of the two groups would have had a lot of difficulty if they had approached this work independently. Together we have been able to go much further than we would have done acting independently”, affirmed Suárez Mascareño.

In the future, the future ArmazoNes high Dispersion Spectrograph (ANDES) of ESO’s Extremely Large Telescope (ELT) in the Atacama Desert (Chile) could study the presence of oxygen in the atmosphere. Other IAC members who have collaborated on this publication are the researchers Rafael Rebolo López, Víctor Sánchez Béjar and Enric Pallé.

To date, more than 5,000 exoplanets have been observed which, thanks to the development of new telescopes and data processing algorithms, allow us to get ever closer to measuring the chemical signatures of life on these planets even though they are light years away. distance in space.