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.

Mars Volcano Apollinaris Patera
13.05.1999

Dwarfed by Olympus Mons and the other immense shield volcanos on Mars, Apollinaris Patera rises only 3 miles or so into the thin martian atmosphere, but bright water-ice clouds can be still be seen hovering around its summit.

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.

The Aurora Tree
20.03.2017

Yes, but can your tree do this? Pictured is a visual coincidence between the dark branches of a nearby tree and bright glow of a distant aurora. The beauty of the aurora -- combined with...

A Rusty Sunset on Mars
4.08.1997

On Mars, sunsets can appear salmon pink. The unusual color is partly due to rust: oxidized iron from Martian dust circulating in the Martian atmosphere. Clouds appear in the morning and evening, but usually evaporate in the midday Sun.

Saturns Rings Seen Sideways
18.10.1998

Saturn's rings are actually very thin. This picture from the Hubble Space Telescope was taken on August 6, 1995 when the rings lined up sideways as seen from Earth. Saturn's largest moon Titan is seen on the left, and Titan's shadow can be seen on Saturn's cloud tops!

Pumpkin Moon
30.10.2004

Does this look familiar? Red and orange hues haunting the face of the Moon might remind you of the October 27th total lunar eclipse, but the picture is actually a montage of images from a similar lunar spectacle in May of 2003.

APOD: 2025 July 6 Б The Spiral North Pole of Mars
6.07.2025

Why is there a spiral around the North Pole of Mars? Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere. This fresh layer is deposited on a water-ice layer that exists year round.

The Worlds Largest Ozone Hole
14.10.1998

It's back, and it's bigger than ever. The ozone hole that has been a cause of concern in recent years has again reformed over Earth's South Pole. The seasonal recurrence of the ozone hole was expected, although the size of the hole has never been so large this early in the season.

Aurora and Orion
14.11.1995

Looking toward the south from low Earth orbit, the crew of the Space Shuttle Endeavor made this stunning time exposure of the Aurora Australis (southern lights) in April of 1994. The aurora are caused by high energy electrons from the Solar Wind which are funneled into the atmosphere by the Earth's magnetic field.