Lake Effect Snow on Earth
30.11.2004

What are those strange clouds stretching out from these lakes? The clouds are caused by cold air moving over a warm water and result in bands of lake-effect snow. The rising bands of moistened, warmed air that drop lake-effect snow alternate with clear bands of falling cold air.

NGC 6872: A Stretched Spiral
25.05.1999

What makes NGC 6872 so long? Measuring over 700,000 light years across from top to bottom, NGC 6872 is one of the largest barred spiral galaxies known. The galaxy's elongated shape might have something to do with its continuing collision with the smaller galaxy IC 4970, visible just above center.

Sunspot 875 Flares
2.05.2006

An unusually active sunspot region is now crossing the Sun. The region, numbered 875, is larger than the Earth and has produced several solar flares over the past week. It should take a few more days for Sunspot 875 to finish crossing the solar disk.

An Iridescent Cloud Over Colorado
25.11.2007

Why would a cloud appear to be different colors? A relatively rare phenomenon known as iridescent clouds can show unusual colors vividly or a whole spectrum of colors simultaneously. These clouds are formed of small water droplets of nearly uniform size.

Bonestell Panorama from Mars
20.01.2009

If you could stand on Mars -- what could you see? One memorable vista might be the above 360-degree panoramic image taken by the robotic Spirit rover over the last year. The above image involved over 200 exposures and was released as part of Spirit's five year anniversary of landing on the red planet.

Milky Way and Stone Tree
29.04.2013

What's that next to the Milky Way? An unusual natural rock formation known as Roque Cinchado or Stone Tree found on the Spanish Canary Island of Tenerife. A famous icon, Roque Cinchado is likely a dense plug of cooled volcanic magma that remains after softer surrounding rock eroded away.

Galaxy Cove Vista
7.05.2013

To see a vista like this takes patience, hiking, and a camera. Patience was needed in searching out just the right place and waiting for just the right time. A short hike was needed to reach this rugged perch above a secluded cove in Julia Pfeiffer Burns State Park in California, USA.

A Fire Rainbow over West Virginia
30.08.2021

What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon.

A Star Cluster in Motion
30.07.2002

Star clusters are a swarm of complex motions. The stars that compose globular clusters and many open clusters all orbit the cluster center, occasionally interacting, gravitationally, with a close-passing star. The orbits of stars around the cluster are typically not as circular as the orbits of planets in our solar system.

GRO J1655 40: Evidence for a Spinning Black Hole
1.06.2003

In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes.