The Comet and the Galaxy
14.03.1999

The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp passed nearly in front of the Andromeda Galaxy. Here the Great Comet of 1997 and the Great Galaxy in Andromeda were photographed together on 1997 March 24th. The problem was the brightness of the Moon.

The Comet and the Galaxy
13.08.2006

The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp passed nearly in front of the Andromeda Galaxy. Here the Great Comet of 1997 and the Great Galaxy in Andromeda were photographed together on 1997 March 24th. The problem was the brightness of the Moon.

A Moon Dressed Like Saturn
16.03.2020

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.

Noctilucent Clouds
15.06.2003

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above.

The Belt of Venus
9.12.2001

Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink.

Noctilucent Clouds
19.06.2005

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above.

The Milky Way over Utah
1.08.2006

If sometimes it appears that the entire Milky Way Galaxy is raining down on your head, do not despair. It happens twice a day. As the Sun rises in the East, wonders of the night sky become less bright than the sunlight scattered by our own Earth's atmosphere, and so fade from view.

A Moon Dressed Like Saturn
2.08.2022

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.

Magma Bubbles from Mt Etna
2.10.2005

Mt. Etna erupted spectacularly in 2001 June. Pictured above, the volcano was photographed expelling bubbles of hot magma, some of which measured over one meter across. One reason planetary geologists study Earth's Mt. Etna is because of its likely similarity to volcanoes on Mars. Mt.

Lunar Shadow Transit
11.03.2016

This snapshot from deep space captures planet Earth on March 9. The shadow of its large moon is falling on the planet's sunlit hemisphere. Tracking toward the east (left to right) across the ocean-covered world the moon shadow moved quickly in the direction of the planet's rotation.