A Filament Across the Sun
20.08.2012

Is that a cloud hovering over the Sun? Yes, but it is quite different than a cloud hovering over the Earth. The long light feature on the left of the above color-inverted image is actually a solar filament and is composed of mostly charged hydrogen gas held aloft by the Sun's looping magnetic field.

Flowing Auroras Over Norway
9.06.2013

Have you ever seen an aurora? Auroras are occurring again with increasing frequency. With the Sun peaking at its eleven year maximum in aurora-triggering activity, it is exhibiting a greater abundance of sunspots, flares, and coronal mass ejections.

A Mercury Transit Sequence
4.05.2016

This coming Monday, Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2006. Because the plane of Mercury's orbit is not exactly coincident with the plane of Earth's orbit, Mercury usually appears to pass over or under the Sun.

Aurora Over Edmonton
4.11.2003

Northern and southern locales saw many a beautiful aurora over the last week, as particles from several large solar flares impacted the Earth. Many reported unusually red auroras, although colors across the spectrum were also seen. Power grids and orbiting satellites braced for the onslaught, but little lasting damage was reported.

Large Eruptive Prominence Imaged by SDO
10.05.2010

Sometimes part of the Sun can just explode into space. These explosions might occur as powerful solar flares, coronal mass ejections, or comparatively tame eruptive solar prominences. Pictured above is one of the largest solar prominence eruptions yet observed, one associated with a subsequent coronal mass ejection.

A Twisted Solar Eruptive Prominence
23.02.2003

A huge eruptive prominence is seen moving out from our Sun in this condensed half-hour time-lapse sequence. Ten Earths could easily fit in the "claw" of this seemingly solar monster. This large prominence, though, is significant not only for its size, but its shape.

A Powerful Solar Flare
29.10.2003

Yesterday, our Sun produced one of the most powerful solar flares in recorded history. Seen across the electromagnetic spectrum, the Sun briefly became over 100 times brighter in X-rays than normal. Over the next few days, as energetic particles emitted from these regions strike the Earth, satellite communications might be affected and auroras might develop.

Lunar Transit from STEREO
3.03.2007

A million miles from planet Earth, last weekend the STEREO B spacecraft found itself in the shadow of the Moon. So, looking toward the Sun, extreme ultraviolet cameras onboard STEREO B were able to record a stunning movie of a lunar transit (aka solar eclipse), as the Moon tracked across the solar disk.

Atlantis and Hubble Side by Side
16.05.2009

On Wednesday, May 13, two, tiny, fast moving spots crossed an otherwise featureless solar disk. Not sunspots though, the dark blemishes were silhouettes of the shuttle orbiter Atlantis and the Hubble Space Telescope side by side.

Aurora Over Clouds
2.04.2001

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.