APOD: 2023 November 26 Б A Dust Jet from the Surface of Comet 67P
25.11.2023

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. In 2016, though, ESA's Rosetta spacecraft not only imaged a jet emerging from Comet 67P/Churyumov-Gerasimenko, but flew right through it.

APOD: 2025 July 27 Б Lightning over the Volcano of Water
26.07.2025

Have you ever watched a lightning storm in awe? You're not alone. Details of what causes lightning are still being researched, but it is known that inside some clouds, internal updrafts cause collisions between ice and snow that slowly separate charges between cloud tops and bottoms.

Comet LINEAR: Fade To Black
13.09.2000

Only last month the stage was set for Comet LINEAR (C/1999S4 LINEAR) to become the first "naked-eye" comet of Y2K. It didn't fill that role, of course, but it did turn in a very dramatic performance.

APOD: 2024 February 13 Б A January Wolf Moon
12.02.2024

Did you see the full moon last month? During every month, on average, a full moon occurs in the skies over planet Earth. This is because the Moon takes a month to complete another...

A Nearby Supernova in Spiral Galaxy M100
6.03.2006

One of the nearer supernovas of recent years was discovered last month in the bright nearby galaxy M100. The supernova, dubbed SN 2006X, is still near its maximum brightness and visible with a telescope...

Pwyll: Icy Crater of Europa
13.04.2002

The impact crater Pwyll (a name from Celtic Mythology) is thought to represent one of the youngest features on the surface of Jupiter's moon Europa. A combination of color and high resolution black...

Running Red Rings Around Jupiter
4.02.1997

Jupiter has rings, too. Unlike Saturn's bright rings which are composed of chunks of ice, Jupiter's rings are darker and appear to consist of fine particles of rock. The six pictures above...

Juno Spots a Complex Storm on Jupiter
27.11.2017

Some storms on Jupiter are quite complex. The swirling storm was captured late last month by the NASA's robotic Juno spacecraft currently orbiting the Solar System's largest planet. The featured image spans about 30,000 kilometers, making this storm system just about as wide as planet Earth.

APOD: 2024 December 16 Б A Kilometer High Cliff on Comet Churyumov Gerasimenko
15.12.2024

This kilometer high cliff occurs on the surface of a comet. It was discovered on the dark nucleus of Comet Churyumov - Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA, which orbited the comet from 2014 to 2016. The ragged cliff, as featured here, was imaged by Rosetta early in its mission.

Potentially Habitable Moons
19.09.2014

For astrobiologists, these may be the four most tantalizing moons in our Solar System. Shown at the same scale, their exploration by interplanetary spacecraft has launched the idea that moons, not just planets, could have environments supporting life.