APOD: 2025 September 22 Б Equinox at Saturn
22.09.2025

On Saturn, the rings tell you the season. On Earth, today marks an equinox, the time when the Earth's equator tilts directly toward the Sun. Since Saturn's grand rings orbit along...

Triton: Neptune's Largest Moon
10.10.1996

Today marks the 150^th anniversary of the discovery of Triton. On October 10 1846, William Lassell was observing the newly discovered planet Neptune. He was attempting to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune had a satellite as well.

Looking Into an Io Volcano
27.03.2002

What would it look like to peer into one of the volcanoes currently active on Jupiter's moon Io? The caldera of Tupan Patera, named after a Brazilian thunder god, reveals itself...

Aurora and Orion
26.01.1997

Looking toward the south from low Earth orbit, the crew of the Space Shuttle Endeavor made this stunning time exposure of the Aurora Australis or southern lights in April of 1994. Aurora are visible at high northern latitudes as well, with the northern lights known as Aurora Borealis.

Retrograde Mars
11.05.2008

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

Saturns Moons Dione and Titan from Cassini
20.04.2010

What would it be like to see a sky with many moons? Such is the sky above Saturn. When appearing close to each other, moons will show a similar phase. A view with...

Space Shuttle Rising
25.05.2011

What's that rising from the clouds? The space shuttle. If you looked out the window of an airplane at just the right place and time last week, you could have seen something very unusual -- the space shuttle Endeavour launching to orbit.

In the Center of Saturns North Polar Vortex
4.12.2012

What's happening at the north pole of Saturn? A vortex of strange and complex swirling clouds. The center of this vortex was imaged in unprecedented detail last week by the robotic Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual hexagonal cloud system that surrounds the north pole of Saturn.

Equinox Earth
28.09.2013

From a geostationary orbit 36,000 kilometers above the equator, Russian meteorological satellite Elektro-L takes high-resolution images our fair planet every 30 minutes. But only twice a year, during an Equinox, can it capture an image like this one, showing an entire hemisphere bathed in sunlight.

Reflections on Planet Earth
2.01.2014

Catching sight of your reflection in a store window or shiny hubcap can be entertaining and occasionally even inspire a thoughtful moment. So consider this reflective view from 300 kilometers above planet Earth.