This exoplanet could be the most metallic planet in existence
Researchers from Italy's University of Turin and the Thüringer Landessternwarte, Germany, have made an exciting discovery: exoplanet GJ 367b is likely completely made of solid iron! This makes it the densest known planet having a short orbital period. First spotted in 2015 by NASA's TESS planet hunter, GJ 367b has a density 1.85 times that of Earth. Using the European Southern Observatory's HARPS spectrograph and TESS observations, scientists determined that over 90% of planet's mass comes from its iron core.
How it transformed from rocky planet to iron core
The origin story of GJ 367b remains a mystery, but it might have once been a rocky planet like Earth or Mars. Its two sibling planets, which orbit farther away, are both rocky, suggesting they all formed similarly. However, GJ 367b probably went through a unique series of events that caused it to lose its outer rocky layers, leaving it with almost all core. Possible explanations include collisions from being so close to its host star.
Radiation might have burned away outer material
Another possibility is that GJ 367b was exposed to intense radiation from being so close to its star, causing its outer material to burn away and leave just the iron core. The outer material might have turned into gas and then been lost to space. It is also possible that GJ 367b went through a combination of collisions and radiation exposure to become the metal planet we know today.
Unanswered questions and future investigations
The big question still remains: how did GJ 367b end up so close to its star? Also, it's unlikely that it formed there. Scientists think that gravitational interactions with other planets might have caused it to move inward from where it originally formed. Studying GJ 367b further could give valuable insights into how rocky planets and planets with short orbital periods form and evolve.
