Total Eclipse of the Active Sun
20.06.2001

A total eclipse of the Sun is that special geocentric celestial event where the Moon passes exactly in front of the solar disk. During a fleeting few minutes of totality, fortunate earthdwellers located within...

X Rays from the Perseus Cluster Core
7.12.2005

The Perseus Cluster of thousands of galaxies, 250 million light-years distant, is one of the most massive objects in the Universe and the brightest galaxy cluster in the x-ray sky. At its core lies the giant cannibal galaxy Perseus A (NGC 1275), accreting matter as gas and galaxies fall into it.

Nix and Hydra
24.06.2006

Discovered in mid-2005, Pluto's small moons were provisionally designated S/2005 P1 and S/2005 P2. They have now been officially christened Nix and Hydra. Compared to Pluto and its large moon Charon...

Total Solar Eclipse Shadow from a Balloon
26.08.2018

Where were you during the Great American Eclipse of 2017? A year ago last week, over 100 million of people in North America went outside to see a partial eclipse of the Sun, while...

Cassini Approaches Saturn
18.04.2020

What would it look like to approach Saturn in a spaceship? One doesn't have to just imagine -- the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and hundreds of thousands more since entering orbit.

The Porpoise Galaxy from Hubble
9.05.2020

What's happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown, was likely a normal spiral galaxy -- spinning, creating stars -- and minding its own business.

Simulation: Formation of the First Stars
29.06.2021

How did the first stars form? To help find out, the SPHINX computer simulation of star formation in the very early universe was created, some results of which are shown in the featured video. Time since the Big Bang is shown in millions of years on the upper left.

Colors of the Moon
14.05.2022

What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different.

X-Ray Stars Of Orion
3.02.2000

The stars of Orion shine brightly in northern winter skies where the constellation harbors the closest large stellar nursery, the Great Nebula of Orion, a mere 1500 light-years away. In fact, the apparently bright...

Cassini Spacecraft Crosses Saturn's Ring Plane
14.02.2010

If this is Saturn, where are the rings? When Saturn's "appendages" disappeared in 1612, Galileo did not understand why. Later that century, it became understood that Saturn's unusual protrusions were rings and that when the Earth crosses the ring plane, the edge-on rings will appear to disappear.