An Intermediate Polar Binary System
10.11.2003

How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk.

Spicules: Jets on the Sun
2.08.2004

Imagine a pipe as wide as a state and as long as half the Earth. Now imagine that this pipe is filled with hot gas moving 50,000 kilometers per hour. Further imagine that this pipe is not made of metal but a transparent magnetic field.

An Intermediate Polar Binary System
21.05.2006

How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk.

An Etruscan Vase Moon Rising
23.02.2009

What's happened to the Moon? Nothing, although from some locations, February's full moon, which occurred about two weeks ago, appeared strangely distorted as it rose. Visible in particular was a curiously inverted...

Flowing Barchan Sand Dunes on Mars
22.04.2012

When does Mars act like a liquid? Although liquids freeze and evaporate quickly into the thin atmosphere of Mars, persistent winds may make large sand dunes appear to flow and even drip like a liquid.

Clouds of the Carina Nebula
16.05.2016

What forms lurk in the mists of the Carina Nebula? The dark ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere.

Clouds of the Carina Nebula
2.05.2021

What forms lurk in the mists of the Carina Nebula? The dark ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere.

The Edge of Space
24.07.2021

Where does space begin? For purposes of spaceflight some would say at the Karman line, currently defined as an altitude of 100 kilometers (60 miles). Others might place a line 80 kilometers (50 miles) above Earth's mean sea level.

Perseids and MAGIC
11.08.2022

On August 11, 2021 a multi-mirror, 17 meter-diameter MAGIC telescope reflected this starry night sky from the Roque de los Muchachos European Northern Observatory on the Canary Island of La Palma. MAGIC stands for Major Atmospheric Gamma Imaging Cherenkov.

APOD: 2024 October 13 Б Aurora Timelapse Over Italian Alps
13.10.2024

Did you see last night's aurora? This question was relevant around much of the world a few days ago because a powerful auroral storm became visible unusually far from the Earth's poles.