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.

A Leonid Meteor Explodes
17.11.1999

Tonight, a lucky few may see a meteor explode. Over the next 36 hours the Earth will pass unusually close to debris expelled from Comet Tempel-Tuttle, causing many sand-sized particles from this comet to enter and burn up in the Earth's atmosphere.

Aurora Over Clouds
10.09.2003

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.

A Green Flash from the Sun
10.11.2002

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.

The Space Shuttle Docked with Mir
20.10.2002

Before there was the International Space Station, the reigning orbiting spaceport was Russia's Mir. Pictured above in 1995, the United States Space Shuttle Atlantis docked with the segmented Mir. During shuttle mission STS-71, astronauts answered questions from school students over amateur radio and performed science experiments aboard Spacelab.

Shadow Cone of a Total Solar Eclipse
6.01.2003

Sometimes, during a total eclipse of the Sun, a strange shadow of darkness can be seen stretching off into the distance. Called a shadow cone, they are visible because the Earth's atmosphere is not completely transparent, scattering sunlight and hence appearing blue during the day.

A Blue Moon Halo over Antarctica
11.08.2015

Have you ever seen a halo around the Moon? Such 22 degree rings around the Moon -- caused by ice crystals falling in the Earth's atmosphere -- are somewhat rare. OK, but have you ever seen a blue moon?

Astro 1 In Orbit
4.05.1996

In December of 1990, the Space Shuttle Columbia carried an array of astronomical telescopes high above the Earth's obscuring atmosphere to observe the Universe at ultraviolet and x-ray wavelengths. The telescopes, known...

APOD: 2025 July 23 Б Fireball over Cape San Blas
23.07.2025

Have you ever seen a fireball? In astronomy, a fireball is a very bright meteor -- one at least as bright as Venus and possibly brighter than even a full Moon. Fireballs are rare -- if you see one you are likely to remember it for your whole life.

A Jewel on the Flower Moon
18.05.2022

Cloudy skies plagued some sky watchers on Sunday as May's Full Flower Moon slipped through Earth's shadow in a total lunar eclipse. In skies above Chile's Atacama desert this telephoto snapshot still captured an awesome spectacle though.