A Flower Shaped Rock on Mars
9.03.2022

It is one of the more unusual rocks yet found on Mars. Smaller than a penny, the rock has several appendages that make it look, to some, like a flower. Although it would...

The Sun Spews X-rays
4.10.1995

Our Sun is really very hot. The Sun's outer atmosphere is so hot that it emits much light in the X-ray band, which was unexpected. X-rays are usually emitted from objects having a temperature in the millions of degrees, not the mere thousands of degrees of the Sun's surface.

Jagged Shadows May Indicate Saturn Ring Particles
15.04.2009

What's causing unusual jagged shadows on Saturn's rings? No one is yet sure. As Saturn nears equinox, its rings increasingly show only their thin edge to the Earth and Sun. As a result, Saturn's moons now commonly cast long shadows onto the rings.

Unknown Dark Material on Mercury
6.07.2009

What is that strange material on Mercury? When flying by Mercury last October, the robotic MESSENGER spacecraft imaged much of the solar system's innermost planet in unprecedented detail. As common in science, new data bring new mysteries.

Mono Lake: Home to the Strange Microbe GFAJ 1
6.12.2010

How strange could alien life be? An indication that the fundamental elements that compose most terrestrial life forms might differ out in the universe was found in unusual Mono Lake in California, USA. Bacteria...

Collapse in Hebes Chasma on Mars
28.05.2017

What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went.

Spiraling Supermassive Black Holes
3.12.2018

Do black holes glow when they collide? When merging, co-orbiting black holes are sure to emit a burst of unusual gravitational radiation, but will they emit light, well before that, if they are surrounded by gas? To help find out, astrophysicists created a sophisticated computer simulation.

APOD: 2023 November 6 Б Red Aurora over Italy
6.11.2023

What was that red glow on the horizon last night? Aurora. Our unusually active Sun produced a surface explosion a few days ago that sent out a burst of electrons, protons, and more massive charged nuclei.

APOD: 2026 January 19 Б CTB 1: The Medulla Nebula
19.01.2026

What powers this unusual nebula? CTB 1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion.

APOD: 2025 September 9 Б Up from the Earth: Gigantic Jet Lightning
9.09.2025

What's that rising up from the Earth? When circling the Earth on the International Space Station early in July, astronaut Nicole Ayers saw an unusual type of lightning rising up from the Earth: a gigantic jet. The powerful jet appears near the center of the featured image in red, white, and blue.