The Milky Way Over Mauna Kea
27.01.2009

Have you ever seen the band of our Milky Way Galaxy? In a clear sky from a dark location at the right time, a faint band of light becomes visible across the sky. Soon after your eyes become dark adapted, you might spot the band for the first time. It may then become obvious.

A Dust Devil on Mars
3.09.2002

Does the surface of Mars change? When inspecting yearly images of the Martian surface taken by the robot spacecraft Mars Global Surveyor currently orbiting Mars, sometimes new dark trails are visible. Although originally...

Galaxy Cluster A2199
22.01.1997

It's bigger than a bread box. In fact, it's much bigger than all bread boxes put together. Abell 2199 is huge. In fact, it is a close, large cluster of galaxies, containing several thousands of galaxies centered around a central dominant galaxy.

The Sagittarius Dwarf Tidal Stream
30.09.2003

Is our Milky Way Galaxy out to lunch? Recent wide field images and analyses now indicate that our home galaxy is actually still in the process of devouring its closest satellite neighbor. This unfortunate...

Penumbral Eclipse Rising
18.02.2017

As seen from Cocoa Beach Pier, Florida, planet Earth, the Moon rose at sunset on February 10 while gliding through Earth's faint outer shadow. In progress was the first eclipse of 2017, a penumbral lunar eclipse followed in this digital stack of seaside exposures.

Milky Way Falls
12.01.2019

It can be the driest place on planet Earth, but water still flows in Chile's Atacama desert, high in the mountains. After discovering this small creek with running water, the photographer returned...

The Hydra Cluster of Galaxies
16.04.2001

The Hydra Cluster of Galaxies contains well over 100 bright galaxies - but perhaps fewer galaxies than might be expected from its mass. Clusters of galaxies are the largest gravitationally bound objects in the universe.

The Sagittarius Dwarf Tidal Stream
29.05.2005

Is our Milky Way Galaxy out to lunch? Recent wide field images and analyses now indicate that our home galaxy is actually still in the process of devouring one of its closer satellite neighbors.

APOD: 2020 August 24 Б Crescent Moon HDR
24.08.2020

How come the crescent Moon doesn't look like this? For one reason, because your eyes can't simultaneously discern bright and dark regions like this. Called earthshine or the da Vinci glow...

APOD: 2025 October 14 Б An Unusual Globule in IC 1396
14.10.2025

Is there a monster in IC 1396? Known to some as the Elephant's Trunk Nebula, parts of gas and dust clouds of this star formation region may appear to take on foreboding forms, some nearly human. The only real monster here, however, is a bright young star too far from Earth to hurt us.