Our Rotating Earth
1.07.2020

Has your world ever turned upside-down? It would happen every day if you stay fixed to the stars. Most time-lapse videos of the night sky show the stars and sky moving above a steady Earth.

Io: The Prometheus Plume
22.05.2011

What's happening on Jupiter's moon Io? Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite image from the robotic Galileo spacecraft that orbited Jupiter from 1995 to 2003.

Lingering Lunar Eclipse
26.07.2000

As the Moon passed almost directly through the center of Earth's shadow on July 16th, sky gazers in the Pacific hemisphere were graced by a lingering lunar eclipse. The total phase lasted 1 hour and 47 minutes, the longest since 1859. A longer total lunar eclipse won't occur until the year 3000.

Saturn at Equinox
30.09.2009

How would Saturn look if its ring plane pointed right at the Sun? Before last month, nobody knew. Every 15 years, as seen from Earth, Saturn's rings point toward the Earth and appear to disappear.

Northern Mercury
1.12.2012

Innermost planet Mercury would probably not be a good location for an interplanetary winter olympics. But new results based on data from the Mercury orbiting MESSENGER spacecraft indicate that it does have substantial water ice in permanently shadowed regions within craters near its north pole.

APOD: 2025 September 11 Б The Umbra of Earth
11.09.2025

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse.

Lunar Eclipse over a Skyscraper
22.11.2021

Why is the Moon on top of this building? Planning. It took the astrophotographer careful planning -- including figuring out exactly where to place the camera and exactly when to take the shot -- to create this striking superposition.

Lunar Eclipses
25.04.2013

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section and is most easily seen during a lunar eclipse. But the complete cross section is larger than the Moon's angular size in the stages of an eclipse.

A Persistent Electrical Storm on Saturn
5.05.2008

How do large storms evolve on Saturn? On Earth, a hurricane can persist for weeks, while the Great Red Spot on Jupiter has been in existence for over 150 years. On Saturn, a storm system has now set a new endurance record, now being discernable for greater than three months.

Eclipse Moon Trail
13.10.2000

Tonight, Friday the 13th, October's big, bright, beautiful full Moon will be in the sky, rising as the sun sets. A time exposure of this evening's full Moon would show a brilliant circular arc or Moon trail tracing its celestial path.