A planet near us with a day that lasts forever and an eternal night illuminated by exploding volcanoes

We know very little about exoplanets. Despite thousands confirmed by astronomers, little is known about their atmosphere, water or anything else that could make them habitable.

We just sometimes know how big they are and even how far they orbit their host.

The claim that a planet was found around a star with volcanoes illuminating its night sky is therefore a big one. So far, researchers have found no evidence of global tectonic activity on planets outside our solar system.

The groundbreaking work, which this week in The astrophysical journal letters, refers to an exoplanet called LHS 3844b, orbiting a red dwarf star – the most common type of star in the Milky Way – about 49 light-years away in the constellation Indus.

What we know about this volcanic planet

Here’s everything you need to know about LHS 3844b:

• It’s a ‘super-earth’, but just – it’s a radius 1.3 times larger than our planet and has 2.25 times its mass.
• A year on LHS 3844b only takes 11 hours – that’s how fast it takes to orbit its star.
• Day and night, LHS 3844b lasts forever. This is because LHS 3844b is tightly connected to its star and points to one side of it – just as the moon is on earth.
• It is a bare, rocky basalt planet that dims it – about the same as Mercury and the dark mares on the moon.
• It probably has no atmosphere, so it is not habitable – and in any case it is 770 ° C on the day side and -250 ° C on the night side.
• Its host is a red dwarf star that is about one-fifth of the Sun.
• Its discovery was announced in September 2018 using data from the Transiting Exoplanet Survey Satellite (TESS).

What’s so weird about LHS 3844b?

Its surface can mostly be covered with dark lava rock, according to observations in 2019 by NASA’s Spitzer Space Telescope. It also discovered that very little heat moves from the star-gazing planet to space at night. This indicates a lack of wind and weather – and therefore no atmosphere.

Now, scientists at the University of Bern and the National Center of Competence in Research NCCR PlanetS in Switzerland have found that the material flows within LHS 3844b from one hemisphere to another. It could be responsible for numerous volcanic eruptions on one side of the planet.

How tectonic activity works on LHS 3844b

“Observing signs of tectonic activity is very difficult because it is usually hidden under an atmosphere,” said Tobias Meier at the Center for Space and Habitability (CSH) at the University of Bern. “We thought that its severe temperature contrast could affect the flow of material into the planet.”

To test the theory, the team performed computer simulations with different strengths of materials and internal heat sources – such as heat from the planet’s core and the decay of radioactive elements.

“Based on what we are used to from the earth, you would expect the material to be lighter on the hot day and thus flow upwards, and vice versa,” said co-author Dan Bower at the University of Bern and the NCCR PlanetS said. However, some simulations have shown the opposite flow direction. “This initial counter-intuitive result is due to the change in viscosity with temperature – cold material is stiffer and therefore does not want to bend, break or subject inside,” Bower said. “Hot material is less tough, so even solid rock becomes more mobile when heated, and can easily flow to the inside of the planet.”

It seems clear that LHS 3844b works in a very different way to the earth, where plate tectonics bring material from the planet’s interior to the surface and atmosphere and then transport it back under the earth’s crust – thus making the earth habitable.

Volcanoes ignite at night on LHS 3844b

The strange material flow in LHS 3844b has bizarre consequences. “On whatever side of the planet the material flows upward, a large amount of volcanism would be expected on that side,” Bower said. “Similar deep-current currents on Earth drive volcanic activity in Hawaii and Iceland”

The conclusion is that LHS 3844b probably contains one hemisphere with volcanoes and one with almost none.

What comes next for LHS 3844b

These conclusions are drawn from computer simulations, and therefore more detailed observations of LHS 3844b are needed – such as a higher resolution map of the surface temperature that can reveal degassing from volcanoes.

How long will it take to get to LHS 3844b?

There’s no good news here / Although 49 light years firmly puts it in our cosmic backyard, LHS 3844b is way too far away to reach it.

If you travel at a light speed, it will take 49 years. Get on a notch with humanity’s fastest moving space probe, New Horizons – moving at 53,000 mph / 53,100 – and it’s going to take 987,026 years to reach LHS 3844b.

I wish you clear sky and wide eyes.