Skip to main content
  1. Home
  2. Space
  3. News

A year lasts just 8 hours on tiny, hellish planet bombarded by radiation

By

Astronomers from the German Aerospace Center Institute of Planetary Research have discovered a terrifying planet: Smaller than Earth and so close to its star that it completes an orbit in just eight hours. Its host star, located relatively nearby at 31 light-years’ distance, is a red dwarf which is smaller and cooler than our sun, but even so, the planet is so close that its surface temperature could reach up to 2,700 degrees Fahrenheit. And the planet is bombarded with radiation that is over 500 times stronger than the radiation on Earth.

Artist im­pres­sion of Plan­et GJ 367
SPP 1992 (Patricia Klein)

The planet, called GJ 367 b, is smaller than most exoplanets discovered so far, which tend to be comparable in size to Jupiter. It has just half the mass of Earth but is slightly larger than Mars with a diameter of 5,500 miles. It was discovered using NASA’s Transiting Exoplanet Survey Satellite (TESS), a space-based planet-hunter that detects planets using the transit method, in which it observes the light from distant stars to look for dips in brightness caused by a planet moving between the star and Earth.

Recommended Videos

After its discovery using TESS, GJ 367 b was further investigated using the European Southern Observatory’s 3.6m Telescope, a ground-based telescope that uses a different method to more precisely determine its radius and mass.

Related

“From the precise determination of its radius and mass, GJ 367 b is classified as a rocky planet,” explained lead researcher Kristine Lam. “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’.”

However, despite its similarities to Earth, you wouldn’t want to move to GJ 367 b. Its surface temperature is so hot it could almost vaporize iron, and the researchers think that the planet may have lost its entire outer layer, called the outer mantle.

But studying the planet could help astronomers learn more about how planets and planetary systems form, which could help us understand more about the development of our own planet and solar system.

When it comes to planets orbiting this close to their stars, called ultra-short period (USP) planets, “We already know a few of these, but their origins are currently unknown,” said Lam. “By measuring the precise fundamental properties of the USP planet, we can get a glimpse of the system’s formation and evolution history.”

The research is published in the journal Science.

Editors' Recommendations

Topics
Georgina Torbet
Georgina Torbet
Space Writer
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
How the ‘hell planet’ covered in lava oceans got so close to its star
An artist’s impression of the planet Janssen (orange circle), which orbits its star so closely that its entire surface is a lava ocean that reaches temperatures of around 2,000 degrees Celsius.

Of the over 5,000 known planets outside our solar system, one of the most dramatic is 55 Cancri e. Affectionately known as the "hell planet," it orbits so close to its star that it reaches temperatures of 3,600 degrees Fahrenheit and its surface is thought to be to covered in an ocean of lava. Located 40 light-years away, the planet has been a source of fascination for its extreme conditions, and recently researchers shared a new theory for how it got so hot.

The planet orbits its star, 55 Cancri A, at a distance of 1.5 million miles which means a year there lasts less than a day here on Earth. “While the Earth completes one orbit around our sun in 365 days, the planet studied here orbits once every 17.5 hours, hugging its host star, 55 Cnc,” said study author Debra Fischer of Yale University in a statement.

Read more
Astronomers find remnants of planets around 10 billion-year-old stars
Artist’s impression of the old white dwarfs WDJ2147-4035 and WDJ1922+0233 surrounded by orbiting planetary debris, which will accrete onto the stars and pollute their atmospheres. WDJ2147-4035 is extremely red and dim, while WDJ1922+0233 is unusually blue.

Far away in the depths of the Milky Way lie two small, dim stars that are in the final stage of their life. At over 10 billion years old, white dwarfs WDJ2147-4035 and WDJ1922+0233 are among the oldest stars in our galaxy, and recently, astronomers discovered something special orbiting around them: the remains of planets, making this one of the oldest known rocky planetary systems.

Astronomers used data from GAIA, the Dark Energy Survey, and the X-Shooter instrument at the European Southern Observatory to peer at this system. They identified debris from orbiting planetesimals, which are globs of dust and rock which are created during planetary formation. The researchers used spectroscopy to look at the light coming from the two white dwarf stars and break it down into different wavelengths, which can show what materials the stars and the surrounding matter are made of.

Read more
Researchers discover planet in the habitable zone of an ultra-cool star
The telescopes of the SPECULOOS Southern Observatory gaze out into the stunning night sky over the Atacama Desert, Chile.

Even though we've discovered over 5,000 exoplanets, or planets outside of our solar system, most of these aren't very Earth-like. They're often much bigger than Earth, being more like gas giants Saturn and Jupiter than small and rocky, and relatively few are located in the habitable zone where liquid water could exist on their surface. That's why it's exciting when a planet comparable to Earth is discovered in its habitable zone -- as one such recently discovered planet is.

Researchers looked at a planet called LP 890-9b or TOI-4306b, previously discovered by NASA's Transiting Exoplanet Survey Satellite. Using a ground-based telescope called SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars), they studied the planet which is around 30% larger than Earth and orbits extremely close to its star, with a year lasting just 2.7 days.

Read more