Mercury Spotting
27.05.2012

Can you spot the planet? The diminutive disk of Mercury, the solar system's innermost planet, spent about five hours crossing in front of the enormous solar disk in 2003, as viewed from the general vicinity of planet Earth.

Coronal Hole
7.02.2002

This ominous, dark shape sprawling across the face of the active Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space.

Dark Sun Sizzling
10.07.2006

Is this our Sun? Yes. Even on a normal day, our Sun is sizzling ball of seething hot gas. Unpredictably, regions of strong and tangled magnetic fields arise, causing sunspots and bright active regions. The Sun's surface bubbles as hot hydrogen gas streams along looping magnetic fields.

Stereo Sun
7.04.2001

This week's stereo offering features the now famous Active Region 9393, the largest sunspot group in the last 10 years. Viewed with red/blue glasses, the stereo pair of images merges into one 3D representation of the Sun with AR9393 above and right of center.

A Spiral Galaxy Gallery
9.04.1996

A progression of beautiful spiral galaxies is illustrated above with three photographs from NASA's Ultraviolet Imaging Telescope (UIT). Flying above the Earth's obscuring layer of atmosphere on the Space Shuttle Columbia during...

Mercury Spotting
6.06.2004

Can you spot the planet? The diminutive disk of Mercury, the solar system's innermost planet, spent about five hours crossing in front of the enormous solar disk on 2003 May 7, as viewed from the general vicinity of planet Earth.

Global Aurora at Mars
6.10.2017

A strong solar event last month triggered intense global aurora at Mars. Before (left) and during (right) the solar storm, these projections show the sudden increase in ultraviolet emission from martian aurora, more than 25 times brighter than auroral emission previously detected by the orbiting MAVEN spacecraft.

Coronal Holes on the Sun
18.03.2003

The ominous, dark shapes haunting the left side of the Sun are coronal holes -- low density regions extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively from...

Mercury Spotting
8.05.2003

Can you spot the planet? The diminutive disk of Mercury, the solar system's innermost planet, spent about five hours crossing in front of the enormous solar disk yesterday (Wednesday, May 7th), as viewed from the general vicinity of planet Earth.

Ghosts in Cassiopeia
31.10.2025

Halloween is an astronomy holiday and spooky shapes always seem to lurk in planet Earth's night skies. In fact, near the center of this telescopic view toward the constellation Cassiopeia these swept-back interstellar clouds IC 59 (left) and IC 63 look ghostly on a cosmic scale.