Carruthers Geocorona Observatory
Carruthers Geocorona Observatory — a small NASA satellite at the Sun–Earth L1 point (launched 24 September 2025, in its halo orbit since 8 January 2026) that images the geocorona: the faint ultraviolet glow of the exosphere, the outermost layer of Earth's atmosphere. It is named after George Carruthers, whose telescope, set up on the Moon during Apollo 16 in 1972, took the first image of the exosphere.
Key facts
Mission & specifications
Mission
- Operator
- NASA
- Launched
- September 24, 2025
- Status
- Active
Trajectory
- Speed rel. Earth
- 77.8 m/s
- Computed from the cached state vector, relative to Earth
- Distance from the Sun
- 0.987 AU
- Computed from the cached position
- Distance from Earth
- 4,221,234 km
- Computed from cached positions
- Distance from Venus
- 0.271 AU
- Computed from cached positions
Mission
The Carruthers Geocorona Observatory is a small NASA satellite built to study the exosphere, the outermost layer of Earth's atmosphere, where hydrogen atoms thin out into space and scatter sunlight as a faint ultraviolet glow: the geocorona. It was launched on 24 September 2025 on the same Falcon 9 as IMAP and SWFO-L1, took its first-light images of the geocorona on 17 November 2025 from near L1, and reached its halo orbit around the Sun–Earth L1 point on 8 January 2026. Its two-year science mission began on 1 March 2026. From L1 its two ultraviolet cameras, a wide-field and a narrow-field imager, see the whole geocorona around Earth, to map its shape, size and density and follow how it responds to space weather. It is named after the physicist and inventor George Carruthers. The first image of Earth's exosphere came from his telescope, set up on the Moon during Apollo 16 in 1972.
- 2025Carruthers launches on a SpaceX Falcon 9 rocketLaunch
With NASA's IMAP and NOAA's SWFO-L1.
- 2025First lightMilestone
Its first images of the geocorona, taken from near L1.
- 2026In its halo orbitArrival
Around the Sun–Earth L1 point, after its third and last manoeuvre.
- 2026Science beginsMilestone
A two-year survey of Earth's exosphere.
Images
Images from open archives · credit shown per image