Space telescope mission · Launched March 2025
SPHEREx
NASA's infrared space telescope, mapping the entire sky in 102 colors.
Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer
See it in 3D
102 colors of light you can't see
Drag across the bars or use the slider. False colors: blue is the shortest wavelength SPHEREx sees, red the longest. Labels mark where water, carbon dioxide and carbon monoxide ices absorb light. Band edges are approximate.
What it is for
How did the universe begin?
Right after the Big Bang, space expanded extremely fast. SPHEREx maps the 3D positions of hundreds of millions of galaxies and looks for traces of that expansion, called inflation, in how they are spread out.
How do galaxies form and grow?
Many galaxies are too faint to see one by one. SPHEREx measures their combined glow instead, to piece together how galaxies have formed and grown over cosmic history.
Where is the water in our galaxy?
In cold clouds where stars are born, water, carbon dioxide and carbon monoxide freeze onto dust grains. SPHEREx looks for the light these ices absorb, tracking the raw ingredients for planets and life.
By the numbers
Its neighbors
- PUNCH
- Four small satellites that work as one instrument to study the Sun's corona. They shared SPHEREx's rocket ride in March 2025.
- James Webb Space Telescope
- SPHEREx finds targets worth a closer look, and Webb provides the detailed follow-up.
- Roman Space Telescope
- Another NASA observatory that can follow up SPHEREx discoveries in more detail.
- WISE
- An earlier infrared telescope that mapped the whole sky, but in far fewer colors.
Timeline
- February 2019
- NASA selects SPHEREx as a Medium-Class Explorer mission.
- March 11, 2025
- Launch on a SpaceX Falcon 9 from California.
- May 2025
- The sky survey begins.
- December 2025
- The first all-sky map is complete.
- Every six months
- Another full scan, until four are done.