Southwest Mercury
13.02.2000

The planet Mercury resembles a moon. Mercury's old surface is heavily cratered like many moons. Mercury is larger than most moons but smaller than Jupiter's moon Ganymede and Saturn's moon Titan. Mercury is much denser and more massive than any moon, though, because it is made mostly of iron.

APOD: 2026 June 19 Б Starry Night II
19.06.2026

Does this scene look familiar? It is a modern recreation of the famous painting Starry Night by Vincent van Gogh. Both the image and the painting depict a tall tree on the left...

Zodiacal Light before Dawn
11.09.2014

You might not guess it, but sunrise was still hours away when this nightscape was taken, a view along the eastern horizon from a remote location in Chile's Atacama desert. Stretching high into...

APOD: 2025 October 13 Б Lemmon Tree
13.10.2025

The tree is not in danger. That's because the comet pictured just above it, Comet C/2025 A6 (Lemmon), is far in the distance, well away from the Earth. Comet Lemmon now continues...

Aurora Slathers Up the Sky
4.01.2020

Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral displays.

Aurora Slathers Up the Sky
14.01.2021

Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral displays.

Venus Transits the Midnight Sun
20.06.2012

Today's solstice, the astronomical beginning of summer in the north, is at 23:09 UT when the Sun reaches the northernmost declination in its yearly trek through planet Earth's sky. While most...

From the Northern to the Southern Cross
27.01.2014

There is a road that connects the Northern to the Southern Cross but you have to be at the right place and time to see it. The road, as pictured above, is actually...

Sky Delights Over Sweden
15.04.2008

This night was a sky enthusiast's delight. While relaxing in Sweden last week, many a cosmic wonder was captured with a single snapshot. They are described here from near to far. In the foreground are nearby trees and more distant snow covered mountains.

Primordial Contact Binary 2014 MU69
22.05.2019

Primordial contact binary 2014 MU69, also known as Ultima Thule, really is very red. In fact, it's the reddest outer solar system object ever visited by a spacecraft from Earth. Its reddish hue is believed to be due to organic materials on its surface.