Astronomers discover Mars-sized exoplanet where a year is eight hours and the ground is molten iron

‘This brings research one step forward in the search for a “second Earth”,’ says expert

Adam Smith
Saturday 04 December 2021 19:21
Comments

Astronomers have found a distant exoplanet where the surface could be made of molten iron.

The planet, classified as GJ 367b, is located 31 light years away from the Earth and has a diameter of just over 9,000km, making it roughly the size of Mars.

"From the precise determination of its radius and mass, GJ 367b is classified as a rocky planet," Kristine Lam of the German Aerospace Centre said.

"It seems to have similarities to Mercury. This places it among the sub-Earth sized terrestrial planets and brings research one step forward in the search for a ‘second Earth’."

Its year lasts under eight hours, making it a part of the ‘ultra-short period’ (USP) group of planets, which orbit their star in less than one Earth day.

Since the planet is so close to the star its surface temperature could reach 1,500C – soaking up more than 500 times the radiation the Earth does.

"We already know a few of these [USP planets] but their origins are currently unknown," said Dr Lam. "By measuring the precise fundamental properties of the USP planet, we can get a glimpse of the system’s formation and evolution history."

Researchers were able to determine the radius and mass of the planet with a high degree of precision measuring its radial velocity – the wobble as it moves towards and away from the Earth – which also gave them more information about its inner structure.

"The high density indicates the planet is dominated by an iron core," said the German Aerospace Centre's Szilárd Csizmadia. "These properties are similar to those of Mercury, with its disproportionately large iron and nickel core that differentiates it from other terrestrial bodies in the Solar System."

GJ 367b is located around a red dwarf star approximately half the size of the sun. Their comparative cool temperature makes spotting planets around them easier to find, and they are some of the most common objects in our galaxy.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in