With the observational power of the James Webb Space Telescope, the world resembling a science fiction film on the “hellish planet” Astrolábos has been unveiled.
Astrolábos, also known as WASP-43b, was discovered in 2011 and is an “exoplanet” classified as a “hot Jupiter,” being the closest orbiting gas giant discovered at that time.
However, what truly happens on this mysterious world remained a puzzle until the “all-seeing eye” of James Webb began peering into deep space from mid-2022, delving into the atmospheres of exoplanets.
The exoplanet Astrolábos orbits very close to its parent star – (Graphic: PHYS).
Hot Jupiters are a type of planet that is similar in size and mass to Jupiter but orbits very closely to its parent star.
Astrolábos is a perfect opposite version of Jupiter, with the same size but heated to extreme temperatures due to its orbit around the parent star taking only 19.2 days.
Astronomer Laura Kreidberg from the Max Planck Institute for Astronomy (MPIA – Germany) and her colleagues have thoroughly analyzed James Webb’s data on this planet, confirming that it is a tidally locked planet with its parent star.
Tidal locking is a phenomenon where two celestial bodies are so close that their gravitational interaction causes the smaller body to always show one face toward the larger body.
A close example is the Moon, which always shows only one face to Earth.
For an exoplanet, this results in one half always being in daylight and the other half always in darkness.
The temperature difference between the day and night hemispheres is extremely high: On Astrolábos, the average temperature on the day side is 1,250 degrees Celsius, while the night side reaches 600 degrees Celsius.
However, 600 degrees Celsius is still excessively hot. The night side has clouds—not barren like the day side, which is too hot for cloud formation—but the clouds there are made of… rock.
Of course, these are not rocks floating in the air, but rocks that have evaporated due to the extremely high temperatures, forming vapor clouds that cannot exist under any conditions on Earth.
The temperature gradient between the two sides, referred to as “temperature slope,” also generates winds reaching speeds of up to 9,000 km/h, sweeping away many elements in the fragile atmosphere of the night side, resulting in a lack of methane.
Scientists have also detected signs of water in the atmosphere of this planet. Water is often an indicator of potential life. However, for this excessively hot planet, the chances for life are almost nonexistent.
