Archive · 15 Dec 2025
NASA Discovers Thick Atmosphere on Rocky Exoplanet
NASA scientists have found that a planet called TOI-561 b, which is bigger than Earth but orbits its star very quickly, has a thick atmosphere.
This is surprising because planets like this were thought to be just solid rock.
The planet is very close to its star, so one side is always super hot, with melted rocks and maybe even a magma ocean.
Scientists used a special telescope to measure the temperature and found it was cooler than expected, suggesting a thick atmosphere with gases and clouds.
They think the planet might have more volatile elements than Earth, and gases flow between the surface and the atmosphere.
They are still studying the data to learn more about the planet's atmosphere.
NASA's James Webb Space Telescope discovered a thick atmosphere on the rocky exoplanet TOI-561 b, which is 1.4 times larger than Earth and orbits its star in less than 11 hours.
TOI-561 b is extremely close to its star, less than a million miles away, and is tidally locked, with one side permanently facing the star and extremely hot.
The planet's unusually low density suggests it has a small iron core and a less dense rocky crust than Earth, possibly due to its formation in a different chemical environment when the universe was young.
Scientists measured the planet's dayside temperature and found it to be cooler than expected, suggesting a dense atmosphere rich in volatile elements that helps cool the planet.
The thick atmosphere on TOI-561 b is surprising because such small, close-in planets are typically thought to be merely solid rock after billions of years of intense radiation.
- Who
- NASA scientists using the James Webb Space Telescope
- What
- Discovered a thick atmosphere on the rocky exoplanet TOI-561 b
- When
- During observations under Webb's General Observers Program 3860
- Where
- TOI-561 b, located in the thick disk region of the Milky Way galaxy
- Why
- To understand the composition and temperature of the planet's atmosphere
- Planet Name
- TOI-561 b
- Size
- 1.4 times larger than Earth
- Orbital Period
- Less than 11 hours
- Distance from Star
- Less than a million miles
- Dayside Temperature
- 3,200 degrees Fahrenheit
- Star Type
- Slightly smaller and less hot than the Sun
- Star Location
- Thick disk region of the Milky Way galaxy
- Observation Tool
- James Webb Space Telescope