A Martian Lake Bed
10.12.1997

Look closely. In this Mars Global Surveyor image of the Martian surface just south of Schiaparelli crater, dark lines appear to criss-cross light colored depressions. One tantalizing possibility is simply that the feature near...

NGC 2440: Cocoon of a New White Dwarf
7.05.2006

Like a butterfly, a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest of all!

Strangers on Mars
21.07.2006

This view from the winter station of Mars Exploration Rover Spirit, looks across the rock strewn landscape of Gusev Crater. The dark boulders and distant hills are characteristic of the region...

APOD: 2024 September 11 Б A Night Sky over the Tatra Mountains
10.09.2024

A natural border between Slovakia and Poland is the Tatra Mountains. A prominent destination for astrophotographers, the Tatras are the highest mountain range in the Carpathians. In the featured image taken...

Looking Back Across Mars
25.05.2010

It's been a long trip for the Martian rover Opportunity. Last week Opportunity surpassed Viking 1 as the longest running mission on Mars, now extending well over six years. Pictured above, Opportunity's tire tracks cross a nearly featureless Martian desert, emanating from a distant horizon.

APOD: 2023 December 24 Б NGC 2440: Cocoon of a New White Dwarf
23.12.2023

What's that in the center? Like a butterfly, a white dwarf star begins its life by casting off a cocoon of gas that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest cocoon of all.

APOD: 2025 September 28 Б Leopard Spots on Martian Rocks
27.09.2025

What is creating these unusual spots? Light-colored spots on Martian rocks, each surrounded by a dark border, were discovered last year by NASA's Perseverance Rover currently exploring Mars. Dubbed leopard spots because...

If You Could Stand on Mars
6.02.1996

If you could stand on Mars - what would you see? Viking 1 robot landers answered this question in 1976 with pictures like the one shown above. The dark rocks, red soil, and green-tinged sky grace this rendition of a normal Martian afternoon. At the bottom corners of the picture are portions of Viking spacecraft.

A Daytime Fireball in 1944
15.11.2000

While stationed in central Africa in December 1944, Norman Appleton witnessed a meteor so bright he remembered it his entire life. Right before his eyes a tremendous smoking fireball streaked across the daytime sky. Years later, as an accomplished member of the Guild of Aviation Artists, he recorded his memories in the above painting.

Moonset, Planet Earth
28.10.2000

During the Astro-1 astronomy mission of December, 1990, Space Shuttle astronauts photographed this stunning view of the full moon rising above the Earth's limb. In the foreground, towering clouds of condensing water vapor mark the extent of the troposphere, the lowest layer of the planet's life-sustaining atmosphere.