Astronomy Picture of the Day

2002-09-20

How does a city-sized neutron star power the vast Crab Nebula? The expulsion of wisps of hot gas at high speeds appears to be at least part of the answer. Yesterday time-lapse movies taken from both the Chandra X-ray Observatory and the Hubble ...

2002-09-19

A day is just under 11 minutes long on 1998 KY26, a 30 meter wide, fast-spinning, water-rich asteroid. This computer simulated view of its lumpy surface has a resolution of about 3 meters and is based on radar and optical observations (click on ...

2002-09-18 AAO

Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of stars, dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun. Next huge filaments of dark ...

2002-09-17 Umar Mohideen

This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is ...

2002-09-15

An unusual triangle of light will be particularly bright near the eastern horizon before sunrise during the next two months for observers in Earth's northern hemisphere. Once considered a false dawn, this triangle of light is actually Zodiacal ...

2002-09-14

This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray ...

2002-09-13 Russell Croman

Anchored in the vast lava flows of the Moon's Oceanus Procellarum lies the Aristarchus Plateau. Recorded from a backyard observatory on planet Earth, this sharp, amazingly colorful view nicely captures the geologically diverse area, including the ...

2002-09-12

In 1572, Danish astronomer Tycho Brahe recorded the sudden appearance of a bright new star in the constellation Cassiopeia. The new star faded from view over a period of months and is believed to have been a supernova, one of the last stellar ...

2002-09-11

Occasionally, a planet in our Solar System will pass in front of a bright star. Since stars and planets take up so little space on the sky, such events are quite rare. Two months ago, however, Pluto and its large moon Charon passed in front of ...

2002-09-10 Lyndon Anderson

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 ...