Volcanic Terrain on Mercury
27.05.2009

Why are many large craters on Mercury relatively smooth inside? Recent images from the robotic MESSENGER spacecraft that flew by Mercury last October show previously uncharted regions of Mercury that have large craters with an internal smoothness similar to the maria on Earth's own Moon.

Saturns Hexagon Comes to Light
22.01.2012

Believe it or not, this is the North Pole of Saturn. It is unclear how an unusual hexagonal cloud system that surrounds Saturn's north pole was created, keeps its shape, or how long it will last.

A Hole in Mars
18.07.2012

What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right.

Earthset from the Lunar Reconnaissance Orbiter
4.01.2016

On the Moon, the Earth never rises -- or sets. If you were to sit on the surface of the Moon, you would see the Earth just hang in the sky. This is because the Moon always keeps the same side toward the Earth.

The Eagle and The Swan
24.08.2017

The Eagle Nebula and the Swan Nebula span this broad starscape, a telescopic view toward the Sagittarius spiral arm and the center of our Milky Way galaxy. The Eagle, also known as M16, is at top and M17, the Swan, at bottom of the frame showing the cosmic clouds as brighter regions of active star-formation.

From the Pleiades to the Eridanus Loop
23.03.2020

If you stare at an interesting patch of sky long enough, will it look different? In the case of Pleiades and Hyades star clusters -- and surrounding regions -- the answer is: yes, pretty different. Long...

Over the Top
19.06.2014

The central bulge of our Milky Way Galaxy rises above a sea of clouds in this ethereal scene. An echo of the Milky Way's dark dust lanes, the volcanic peak in foreground silhouette is on France's Réunion Island in the southern Indian Ocean.

Shells in the Egg Nebula
26.06.1999

The Egg Nebula is taking a beating. Like a baby chick pecking its way out of an egg, the star in the center of the Egg Nebula is casting away shells of gas and dust as it slowly transforms itself into a white dwarf star.

Massive Stars in Open Cluster Pismis 24
19.12.2006

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder.

Beautiful Spiral NGC 7331
22.10.2008

A favorite target for astronomers, big, beautiful spiral galaxy NGC 7331 is one of the brighter galaxies not found in Charles Messier's famous 18th century catalog. About 50 million light-years distant...