The Suns Heliosphere and Heliopause
24.06.2002

Where does the Sun's influence end? Nobody is sure. Out past the orbits of Neptune and Pluto extends a region named the heliosphere where the Sun's magnetic field and particles from the Solar Wind continue to dominate.

Spicules: Jets on the Sun
2.08.2004

Imagine a pipe as wide as a state and as long as half the Earth. Now imagine that this pipe is filled with hot gas moving 50,000 kilometers per hour. Further imagine that this pipe is not made of metal but a transparent magnetic field.

A Partial Eclipse of an Active Sun
2.11.2022

Watch for three things in this unusual eclipse video. First, watch for a big dark circle to approach from the right to block out more and more of the Sun. This dark circle is the Moon, and the video was made primarily to capture this partial solar eclipse last week.

APOD: 2024 October 13 Б Aurora Timelapse Over Italian Alps
13.10.2024

Did you see last night's aurora? This question was relevant around much of the world a few days ago because a powerful auroral storm became visible unusually far from the Earth's poles.

Planetary Nebula Mz3: The Ant Nebula
5.02.2001

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?

Planetary Nebula Mz3: The Ant Nebula
1.05.2005

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?

Comet Encke s Tail Ripped off
3.10.2007

Swinging inside the orbit of Mercury, on April 20th periodic comet Encke encountered a blast from the Sun in the form of a Coronal Mass Ejection (CME). When CMEs, enormous clouds of energetic particles ejected from the Sun, slam into Earth's magnetosphere, they often trigger auroral displays.

Spicules: Jets on the Sun
2.11.2010

Imagine a pipe as wide as a state and as long as the Earth. Now imagine that this pipe is filled with hot gas moving 50,000 kilometers per hour. Further imagine that this pipe is not made of metal but a transparent magnetic field.

Orion over Green Bank
23.02.2022

What will the huge Green Bank Telescope discover tonight? Pictured, the Robert C. Byrd Green Bank Telescope (GBT) on the lower right is the largest fully-pointable single-dish radio telescope in the world. With...

Filaprom on the Western Limb
24.06.2022

A solar filament is an enormous stream of incandescent plasma suspended above the active surface of the Sun by looping magnetic fields. Seen against the solar disk it looks dark only because it's a little cooler, and so slightly dimmer, than the solar photosphere.