It has been named K2-229 b and is the size of Earth, but its mass is comparable to that of Mercury. Like him, it is a ‘large metal ball’ with enormous density , and it has a very thin composition of rock on its surface.
The HARPS spectrograph of the European Southern Observatory has located this new planet, an analog of Mercury, which is part of a planetary system 340 light years away that orbits a star very similar to the Sun.
Your observations will help to better understand how Mercury formed.
Mercury is something of a large gigantic metal sphere , ‘varnished’ with rock , and scientists speculate that it is actually the core of what was once a larger planet, since it has only a thin layer of rock. , compared to its large metal core. This gives it a huge mass.
A planet of the same composition as Mercury attracts attention, and excites the curiosity of scientists about its formation. Unlike other known planets, such as Venus, Mars or the Earth itself, which have a mass composed of approximately 30% metallic nucleus and 70% silicate mantle, K2-229 b is essentially made up of a metallic nucleus, same as Mercury.
Various scenarios have been proposed to explain this extraordinary composition. One of them is that an impact could have ripped the outer layers of this planet , leaving its core practically bare. The same could happen to Mercury, although these hypotheses are still highly debated by scientists.
In addition to helping catalog other Mercury-like planets, the finding of K2-229 b will help detail the field observations of our closest neighbor to the Sun (with MESSENGER and BepiColombo8) in the general context of the formation and evolution of terrestrial planets. solar and extrasolar.
Reference: ‘An Earth-sized exoplanet with a Mercury-like composition’. A. Santerne, B. Brugger, A. Vigan. Nature Astronomy (2018). Doi: 10.1038 / s41550-018-0420-5
