Astronomers have taken an exciting step forward in understanding planets beyond our solar system by studying not just their atmospheres, but their actual surfaces.
Using the powerful James Webb Space Telescope, researchers have examined the rocky exoplanet LHS 3844 b and uncovered clues about what its surface might be made of.
LHS 3844 b is a so-called “super-Earth,” meaning it is larger than our planet, about 30% bigger in size.
It orbits a small, cool star known as a red dwarf and completes one orbit in just 11 hours. Because it is so close to its star, the planet is tidally locked, which means the same side always faces the star.
This creates a permanent dayside that is extremely hot, reaching temperatures of around 1,000 Kelvin, or about 725 degrees Celsius.
What makes this planet especially interesting is that it appears to have no atmosphere at all.
According to lead researcher Laura Kreidberg, the data show a dark, hot, and barren surface. Without an atmosphere to trap heat or protect it, the planet is constantly exposed to intense radiation from its star.
To study this distant world, scientists used an instrument called MIRI on the James Webb Space Telescope. Instead of taking pictures directly, they measured infrared light coming from the planet.
By breaking this light into different wavelengths, they created what is known as a spectrum, which acts like a fingerprint for different materials. This allowed them to compare the planet’s surface with known rocks and minerals from Earth, the Moon, and Mars.
Their analysis showed that LHS 3844 b does not have a surface like Earth’s crust, which is rich in minerals such as granite.
On Earth, this kind of crust forms through long-term geological processes involving plate tectonics and water. The absence of similar materials on LHS 3844 b suggests that it likely does not have Earth-like tectonic activity and may contain very little water.
Instead, the planet’s surface appears to be much darker and more similar to basalt, a type of volcanic rock commonly found on the Moon and in Earth’s mantle. This points to two possible scenarios.
One is that the planet has a relatively fresh surface made of solid volcanic rock, possibly created by recent volcanic activity. The other is that the surface is covered by a layer of fine, dark dust, called regolith, which forms over time as rocks are broken down by radiation and meteorite impacts.
To figure out which scenario is more likely, scientists looked for signs of volcanic gases such as sulfur dioxide. If the planet were geologically active, these gases might be detected.
However, no such signals were found, making recent volcanic activity less likely. This leads researchers to favor the second scenario, where the planet’s surface is older and covered in dark, weathered dust, similar to what we see on Mercury or the Moon.
Even so, the mystery is not fully solved. The research team is now using additional observations from the James Webb Space Telescope to study how light reflects off the planet’s surface at different angles. This could help them distinguish between solid rock and dusty material more clearly.
This study marks an important step in exploring the geology of distant worlds. It shows that even planets dozens of light-years away can reveal their secrets, helping us better understand how planets form and evolve across the universe.
Source: KSR.
