A purple glow arcs across the night sky. Just another aurora, or is it? First described in 2018, this is a STEVE — Strong Thermal Emission Velocity Enhancement. (Yes, the Keep reading
Tag: solar wind
A Comet’s Two Tails
The bright tail of a comet doesn’t actually stream out behind it. Instead, the tail points away from the sun, showing off all the ice, dust, and gas blown off Keep reading
Eerie Aurora
This surreal image comes from an aurora on Halloween 2013. Photographer Ole C. Salomonsen captured it in Norway during one of the best auroral displays that year. The shimmering green Keep reading
Martian Auroras
Auroras happen when energetic particles — usually from the solar wind — interact with the atmosphere. Here on Earth, they’re most often found near the poles, where our strong global Keep reading
A Comet’s Tail
A comet‘s tail changes from day-to-day depending on how much material the comet is losing and how strong the solar wind it’s facing is. This image sequence shows Comet 12P/Pons-Brooks Keep reading
The Unusual Auroras of Mars
Earth, Saturn, and Jupiter have auroras at their poles, generated by the interaction of their global magnetic fields with the solar wind. Mars has no global magnetic field, only remnants Keep reading
Escaping the Sun
One enduring mystery of the solar wind — a stream of high-energy particles expelled from the sun — is how the particles get accelerated in the first place. The sun Keep reading
A Comet’s Tail Swept Away
On Christmas Day 2021, Comet Leonard put on a show in our skies. Though the comet was a pale streak to the naked eye, photographer Gerald Rhemann caught a striking Keep reading
Brilliant Auroras
Glowing auroras billow across Canada in this satellite image from a recent geomagnetic storm. As our sun enters a more active part of its solar cycle, we can expect more Keep reading
Space Hurricanes
Researchers have observed their first “space hurricane” – a 1,000-km-wide vortex of plasma – in Earth’s upper atmosphere. Like conventional hurricanes, this storm featured precipitation (of electrons rather than rain), Keep reading