Trees, Stars, Aurora
9.02.2012

Have you ever seen an aurora? Auroras are occurring again with increasing frequency. With the Sun being unusually dormant over the past four years, the amount of Sun-induced auroras has been unusually low. More recently, however, our Sun has become increasingly active and exhibiting a greater abundance of sunspots, flares, and coronal mass ejections.

Solar Flare in the Gamma ray Sky
15.03.2012

What shines in the gamma-ray sky? The answer is usually the most exotic and energetic of astrophysical environments, like active galaxies powered by supermassive black holes, or incredibly dense pulsars, the spinning remnants of exploded stars.

All Planets Panorama
24.02.2017

For 360 degrees, a view along the plane of the ecliptic is captured in this remarkable panorama, with seven planets in a starry sky. The mosaic was constructed using images taken during January 24-26, from Nacpan Beach, El Nido in Palawan, Philippines.

APOD: 2024 September 10 Б Horsehead and Orion Nebulas
9.09.2024

The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, they appear in opposite corners of the above stunning mosaic.

Centaurus A: The Galaxy Deep Inside
3.12.1998

Deep inside Centaurus A, the closest active galaxy to Earth, lies ... another galaxy! Cen A is a giant elliptical galaxy a mere 10 million light-years distant with a central jumble of stars, dust, and gas that probably hides a massive black hole.

A MACHO View of Galactic Dark Matter
1.02.1996

What is our Galaxy made of? Stellar motions indicate there is much more mass than just stars and gas. Photographs like the two shown above may be yielding a clue about the dark matter, however.

SpaceShipOne
27.06.2003

Slung below its equally innovative mothership dubbed White Knight, SpaceShipOne rides above planet Earth, photographed during a recent flight test. SpaceShipOne was designed and built by cutting-edge aeronautical engineer Burt Rutan and his company Scaled Composites to compete for the X Prize.

The Whale and the Hockey Stick
12.10.2007

NGC 4631 is a big beautiful spiral galaxy seen edge-on (top right) only 25 million light-years away towards the small northern constellation Canes Venatici. This galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others the popular moniker of The Whale Galaxy.

Huygens: Titan Descent Movie
21.01.2013

What would it look like to land on Saturn's moon Titan? The European Space Agency's Huygens probe set down on the Solar System's cloudiest moon in 2005, and a time-lapse video of its descent images was created.

Moonless Meteors and the Milky Way
12.08.2015

Have you watched the Perseid meteor shower? Though the annual shower's predicted peak was last night, meteor activity should continue tonight (August 13/14), best enjoyed by just looking up in clear, dark skies after midnight. Of course, this year's Perseid shower has the advantage of being active near the August 14 New Moon.