APOD: 2004 August 27- The Sedna Scenario
27.08.2004

The discovery of Sedna (aka 2003 VB12), the most distant known object orbiting the Sun, presents a mystery. Pluto's orbit averages about 40 AU in radius, where an AU (Astronomical Unit) is the Earth-Sun distance.

M31 versus M33
26.09.2015

Separated by about 14 degrees (28 Full Moons) in planet Earth's sky, spiral galaxies M31 at left, and M33 are both large members of the Local Group, along with our own Milky Way galaxy.

Saturn at Night
12.09.2006

This is what Saturn looks like at night. In contrast to the human-made lights that cause the nighttime side of Earth to glow faintly, Saturn's faint nighttime glow is primarily caused by sunlight reflecting off of its own majestic rings.

Mars at Closest Approach 2016
9.08.2016

When does Mars appear the largest? This occurs when Earth sweeps past Mars in their respective orbits around the Sun, creating a momentary Sun-Earth-Mars alignment called opposition. The featured video shows the Mars opposition that occurred earlier this year. All of the images were taken from Earth with a small telescope.

Tycho and Clavius at Dawn
16.07.2022

South is up in this dramatic telescopic view of the lunar terminator and the Moon's rugged southern highlands. The lunar landscape was captured on July 7 with the moon at its first quarter phase.

AR 2192: Giant on the Sun
24.10.2014

As you (safely!) watched the progress of yesterday's partial solar eclipse, you probably also spotted a giant sunspot group. Captured in this sharp telescopic image from October 22nd the complex AR 2192 is beautiful to see, a sprawling solar active region comparable in size to the diameter of Jupiter.

Spirit Encounters Soft Ground on Mars
1.06.2009

Will Spirit be able to free itself from soft ground on Mars? The robotic Spirit rover currently rolling across Mars ran into unexpectedly soft ground last month while exploring the red planet. A worry...

M31 versus M33
26.09.2013

Separated by about 14 degrees (28 Full Moons) in planet Earth's sky, spiral galaxies M31 ,left, and M33 are both large members of the Local Group, along with our own Milky Way galaxy.

A Shadow on the Rings of Saturn
21.07.2004

This picture of Saturn could not have been taken from Earth. No Earth based picture could possibly view the night side of Saturn and the corresponding shadow cast across Saturn's rings. Since Earth is much closer to the Sun than Saturn, only the day side of the planet is visible from the Earth.

Sun Halo at Sixty three Degrees North
21.12.2022

Happy Solstice! Today is the December solstice, marking an astronomical beginning of summer in the southern hemisphere and winter in the north. On its yearly trek through planet Earth's skies, at this solstice the Sun reaches its southern most declination, 23.5 degrees south, at 21:48 UTC.