Creature Aurora Over Norway
6.11.2013

It was Halloween and the sky looked like a creature. Exactly which creature, the astrophotographer was unsure (but possibly you can suggest one). Exactly what caused the eerie apparition was sure: one of the best auroral displays in recent memory. This spectacular aurora had an unusually high degree of detail.

A Rocket Booster Falls Back to Earth
1.08.2016

What's that crossing the sky? Although it looked a bit like a large meteor, it was actually the booster of a Chinese rocket returning to Earth after its launch two days earlier.

Northern Lights and Noctilucent Clouds
20.06.2018

Skies after the near-solstice sunset on June 17 are reflected in this calm lake. The tranquil twilight scene was captured near Bashaw, Alberta, Canada, northern planet Earth. Usually spotted at high latitudes in summer months, night shining or noctilucent clouds hang just above the horizon, transfusing light into a darker sky.

NGC 6934 from Gemini North
30.06.1999

What's going on near the center of globular cluster NGC 6934? The blur caused by the Earth's atmosphere has prevented astronomers from discerning individual stars in this unusual environment. Telescopes in space can help, but the new Gemini North telescope took the above picture from the ground.

A Small Double Ozone Hole in 2002
22.10.2002

As expected, the ozone hole near Earth's South Pole is back again this year. This time, however, it's smaller than the past two years, and has an unusual double lobe structure. Ozone is important because it shields us from damaging ultraviolet sunlight.

Planets Over Easter Island
24.05.2004

It isn't every day that planets line up behind a stone giant. For one thing, it helps to have a good planet line-up, such as occurred in the sky just last month. For another, it helps to be on Easter Island, where over 800 large stone statues exist.

Nearer To Asteroid Eros
7.03.2000

As the robot spacecraft NEAR lowers itself toward asteroid 433 Eros, more surface details are becoming visible. Last week's maneuvers brought NEAR to within 204 kilometers of the floating mountain's surface. With...

Ash and Lightning Above an Icelandic Volcano
19.04.2010

Why did the recent volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well populated areas.

Mammatus Clouds Over Olympic Valley
19.02.2011

What's happened to these clouds? Normal cloud bottoms are flat because moist warm air that rises and cools will condense into water droplets at a very specific temperature, which usually corresponds to a very specific height. After water droplets form that air becomes an opaque cloud.

Ash and Lightning above an Icelandic Volcano
20.04.2014

Why did a picturesque 2010 volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well-populated areas.