Four Faces of Mars
5.07.1999

As Mars rotates, most of its surface becomes visible. During Earth's recent pass between Mars and the Sun, the Hubble Space Telescope was able to capture the most detailed time-lapse pictures ever from the Earth. Dark and light sand and gravel create an unusual blotted appearance for the red planet.

Almost Three Tails for Comet Encke
20.02.2017

How can a comet have three tails? Normally, a comet has two tails: an ion tail of charged particles emitted by the comet and pushed out by the wind from...

APOD: 2023 April 30 Б Saturns Moon Helene in Color
30.04.2023

Although its colors may be subtle, Saturn's moon Helene is an enigma in any light. The moon was imaged in unprecedented detail in 2012 as the robotic Cassini spacecraft orbiting Saturn swooped to within a single Earth diameter of the diminutive moon.

HH 222: The Waterfall Nebula
24.10.2011

What created the Waterfall Nebula? No one knows. The structure seen in the region of NGC 1999 in the Great Orion Molecular Cloud complex is one of the more mysterious structures yet found on the sky. Designated HH-222, the elongated gaseous stream stretches about ten light years and emits an unusual array of colors.

APOD: 2005 December 28- Smooth Sections on Asteroid Itokawa
28.12.2005

What are parts of this asteroid's surface so smooth? No one is yet sure, but it may have to do with the dynamics of an asteroid that is a loose pile of rubble rather than a solid rock.

Space Station Silhouette on the Moon
2.04.2019

What's that unusual spot on the Moon? It's the International Space Station. Using precise timing, the Earth-orbiting space platform was photographed in front of a partially lit gibbous Moon last month. The featured image was taken from Palo Alto, California, USA with an exposure time of only 1/667 of a second.

El Nino Earth
12.11.1997

El Niño is a temporary global climate change resulting from unusually warm water in the central Pacific Ocean. El Niño can cause unusual or severe weather for some locations over the next few months.

A Berry Bowl of Martian Spherules
5.04.2004

How were these unusual Martian spherules created? Thousands of unusual gray spherules, made of iron and rock but dubbed blueberries, were found embedded in and surrounding rocks near the landing site of the robot Opportunity rover on Mars.

Omega Sunrise
21.09.2020

Capturing this sunrise required both luck and timing. First and foremost, precise timing was needed to capture a sailboat crossing right in front of a rising Sun. Additionally, by a lucky coincidence, the background Sun itself appears unusual -- it looks like the Greek letter Omega (н).

Rembrandt Impact Basin on Mercury
4.05.2009

Why do portions of this huge crater on Mercury have so much iron? The unusual Rembrandt impact basin was discovered recently in images taken during the robotic MESSENGER spacecraft's 2008 October flyby of the Solar System's innermost planet.