GRACE Maps the Gravity of Earth
23.07.2003

Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface, slight distance changes between a pair of identically orbiting satellites named GRACE have been used to create the best ever map of Earth's gravitational field.

Earths Shrinking Antarctic Ice Sheet
8.03.2006

Is the continent at the end of the Earth slowly melting? For millions of years, Antarctica, the frozen continent at the southern end of planet Earth, has been encased in a gigantic sheet of ice. Recently, the orbiting robotic GRACE satellite has been taking sensitive measurements of the gravity for the entire Earth, including Antarctica.

The Potsdam Gravity Potato
14.12.2014

Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface, sensitive measurments by the orbiting satellites GRACE and CHAMP were used to create a map of Earth's gravitational field.

A Gravity Map of Earth
13.11.2001

Is gravity the same over the surface of the Earth? No -- it turns out that in some places you will feel slightly heavier than others. The above relief map shows in exaggerated highs and lows where the gravitational field of Earth is relatively strong and weak.

Aurora in Red and Yellow
10.04.2000

The past week brought some spectacular aurora to northern skies. These aurorae were caused by a large interplanetary shock wave that exploded from the Sun on April 4. When the shock wave reached the Earth on April 6, the resulting aurora could be seen in clear skies as far south as North Carolina.

Planets and Fire by Moonlight
9.07.2008

On July 5th, wandering planets, bright stars, and a young crescent Moon graced western skies after sunset. Arrayed along the solar system's ecliptic plane, the three celestial beacons forming this skyscape's eye-catching line-up with the Moon are Saturn (upper left), then Mars, and finally Regulus, alpha star of the constellation Leo.

Comet Country
27.03.1997

Moonlight illuminates the landscape and lends a painterly quality to this beautiful photograph of the Absaroka mountain range, located along the Montana-Wyoming border near the USA's Yellowstone National Park. In the foreground lies the North Fork of the Shoshone River.

Comet Over Krakow
13.01.2007

Bright Comet McNaught (C/2006 P1) graced the twilight this week, seen by many and often described with superlatives. Watching the skies over Krakow, Poland, Andrzej Sawow recorded this view on Wednesday - with an ordinary handheld digital camera. He notes that "... astronomy is really for everyone who loves to look at the night sky.

Aurora Over Iowa
18.12.2006

Last Thursday evening, stars were not the only lights in Iowa skies. Spectacular northern lights also shone from the heavens, extending across the midwestern USA and other locations not often graced with auroral displays.

Venus Beyond the Storm
10.09.2002

A thunderstorm, lightning, a bright star and a bright planet all graced an evening sky for a short while near Bismarck, North Dakota, USA two weeks ago. Thick thunderclouds from a passing storm are the origin of a strong cloud to ground lightning strike.