Comet Wild 2s Nucleus from Stardust
3.01.2004

What does a comet nucleus look like? Yesterday the robot spacecraft Stardust answered this question by returning the most detailed images yet of the center of a comet. The icy centers of comets are usually hidden from Earth-bound telescopes by opaque dust and gas that boils off during approach to the Sun.

Mercury on the Horizon
27.01.2008

Have you ever seen the planet Mercury? Because Mercury orbits so close to the Sun, it never wanders far from the Sun in Earth's sky. If trailing the Sun, Mercury will be visible low on the horizon for only a short while after sunset.

A Horizon Rainbow in Paris
27.03.2013

Why is this horizon so colorful? Because, opposite the Sun, it is raining. What is pictured above is actually just a common rainbow. It's uncommon appearance is caused by the Sun being unusually high in the sky during the rainbow's creation.

IC 1848: The Soul Nebula
15.04.2013

Stars are forming in the Soul of the Queen of Aethopia. More specifically, a large star forming region called the Soul Nebula can be found in the direction of the constellation Cassiopeia, who Greek mythology credits as the vain wife of a King who long ago ruled lands surrounding the upper Nile river.

A Supercell Thunderstorm Over Texas
18.06.2013

Is that a cloud or an alien spaceship? It's an unusual and sometimes dangerous type of thunderstorm cloud called a supercell. Supercells may spawn damaging tornados, hail, downbursts of air, or drenching rain. Or they may just look impressive.

Cap Cloud over the Sierra Nevadas
26.11.2013

One might say this was a bell weather day for the Sierra Nevada mountains. In January, just as the Sun was setting above the district of AlbayzМn in Grenada, Spain, a huge cloud appeared as a bell capping the Veleta peak.

The Pleiades Deep and Dusty
25.02.2014

The well known Pleiades star cluster is slowly destroying part of a passing cloud of gas and dust. The Pleiades is the brightest open cluster of stars on Earth's sky and can be seen from almost any northerly location with the unaided eye.

The Extraordinary Spiral in LL Pegasi
11.12.2016

What created the strange spiral structure on the left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

Supernumerary Rainbows over New Jersey
2.10.2018

Yes, but can your rainbow do this? After the remnants of Hurricane Florence passed over Jersey Shore, New Jersey, USA last month, the Sun came out in one direction but something quite unusual appeared in the opposite direction: a hall of rainbows.

Animation: Spiral Disk around a Black Hole
20.08.2019

What would it look like to orbit a black hole? Many black holes are surrounded by swirling pools of gas known as accretion disks. These disks can be extremely hot, and much of the orbiting gas will eventually fall through the black hole's event horizon -- where it will never been seen again.