The Great Russian Meteor of 2013
18.02.2013

What in heaven's blazes is that? Thousands of people living near the Ural Mountains in Russia saw last Friday morning one of the more spectacular meteors of modern times streak across the sky. Forceful sound waves arrived at the ground minutes later, knocking people over and breaking windows for hundreds of kilometers.

The Orbiting Hubble Space Telescope
10.08.1995

The Hubble Space Telescope (HST) is the largest orbiting public optical telescope in history. Its 2.4 meter diameter reflecting mirror and its perch above Earth's atmosphere allow it to create exceptionally sharp images.

APOD: 2025 September 2 Б The Horsehead and Flame Nebulas
2.09.2025

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright emission nebula.

Aurora Over the Chugach Mountains
29.09.2003

Auroras can make spectacular sights. Photographed above, flowing green auroras help the Moon illuminate the serene Portage Lake and the snowy Chugach Mountains near Anchorage, Alaska, USA. Although auroras might first appear to be moonlit clouds, they only add light to the sky and do not block background stars from view.

Meeting in the Mesosphere
4.07.2020

A sensitive video camera on a summit of the Vosges mountains in France captured these surprising fireworks above a distant horizon on June 26. Generated over intense thunderstorms, this one about 260 kilometers away, the brief and mysterious flashes have come to be known as red sprites.

Flying over Planet Earth
27.09.2011

Have you ever dreamed of flying high above the Earth? Astronauts visiting the International Space Station do this every day, circling our restless planet twice every three hours. A dramatic example of their view was compiled in the above time-lapse video from images taken earlier this month.

Real Time Perseid
8.09.2018

Bright meteors and dark night skies made this year's Perseid meteor shower a great time for a weekend campout. And while packing away their equipment, skygazers at a campsite in the mountains...

Perseid Meteors over Turkey
1.08.2017

The Perseid Meteor Shower, usually the best meteor shower of the year, will peak late next week. A person watching a clear sky from a dark location might see a bright meteor every minute.

Aurora at Midnight
5.05.1998

What's happening behind those trees? Aurora. This picture was taken at midnight near Fairbanks, Alaska, and captures familiar trees, common clouds, and a glowing sky markedly different than a sunset. Particularly strange is the green auroral ring caused by ionized oxygen high in the Earth's atmosphere.

A Green Flash from the Sun
7.05.2000

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.