Kepler-22b is an exoplanet discovered by NASA's Kepler mission in 2009 and confirmed in 2011.

Kepler-22b is an exoplanet discovered by NASA's Kepler mission in 2009 and confirmed in 2011. It's located about 600 light-years away in the constellation Cygnus. Kepler-22b is notable because it orbits within its star's **habitable zone**, the region around a star where conditions might allow liquid water to exist—crucial for the possibility of life.

Here’s how Kepler-22b "works" in terms of its characteristics:

1. **Orbit and Star**:
- Kepler-22b orbits a star similar to our Sun, known as Kepler-22. The planet completes an orbit in about 290 days, which is slightly shorter than Earth's year (365 days).

2. **Habitable Zone**:
- Its distance from its star puts it within the star's habitable zone, where temperatures could potentially allow for liquid water if other conditions are right. This is important because water is considered a key ingredient for life as we know it.

3. **Size**:
- Kepler-22b is about 2.4 times the radius of Earth, making it a **super-Earth**—a planet larger than Earth but smaller than gas giants like Neptune. Its mass and composition remain uncertain, but it could be rocky, gaseous, or have a thick atmosphere.

4. **Atmosphere**:
- Not much is known about the atmosphere of Kepler-22b. If it has a thick atmosphere, it could trap heat and affect the surface temperature, possibly making it hotter than expected. Future missions may gather more data on its atmosphere.

In short, Kepler-22b is intriguing because it orbits in the "Goldilocks zone" around its star, raising the possibility that it might have the right conditions for water and potentially life, though much more data is needed to confirm this.