The electron density peaks well after the activity of the moon’s distinctive south polar ice plume reaches its maximum, but the cause of the lag remains puzzling.
Planetary magnetospheres
Posted inResearch Spotlights
How Mars’s Magnetic Field Let Its Atmosphere Slip Away
A planet’s magnetic field usually protects its atmosphere from being blown away by its star. But new research suggests Mars’s weak magnetic field may have helped its atmosphere escape.
Posted inNews
Computers Tease Out Secrets of Jupiter’s Aurorae
Aurorae once classified by human eyes are now being sorted by machines. The change may help astronomers understand how the mysterious features are powered.
Posted inEditors' Highlights
A Close-in Look at Saturn’s Periodic Space Bubble
When it comes to Saturn’s space environment, summer wins over winter in controlling the periodic flows of electrically charged particles and magnetic fields.
Posted inEditors' Vox
Filling Earth’s Space Environment from the Sun or the Earth?
The editor of a new book describes how a unique combination of the monograph and video show that a four-decade old paradigm in solar-terrestrial physics is changing.
Posted inResearch Spotlights
Hubble Gazes at Europa's Aurora
Scientists get their best glimpse yet of the shimmering phenomena on one of Jupiter's most intriguing moons.