APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Persistent Saturnian Auroras
Explanation: Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraft monitored Saturn's South Pole simultaneously as Cassini closed in on the gas giant in January 2004. Hubble snapped images in ultraviolet light , while Cassini recorded radio emissions and monitored the solar wind . Like on Earth, Saturn's auroras make total or partial rings around magnetic pole s. Unlike on Earth, however, Saturn's auroras persist for days, as opposed to only minutes on Earth . Although surely created by charged particles entering the atmosphere, Saturn's auroras also appear to be more closely modulated by the solar wind than either Earth's or Jupiter's auroras . The above sequence shows three Hubble images of Saturn each taken two days apart.
| Date | June 22, 2014 |
|---|---|
| Credit | Image Credit: J. Clarke ( Boston U. ) & Z. Levay ( STScI ), ESA , NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



