Astronomy Picture of the Day

2004-04-02 Jimmy Westlake

Doing their part in the ongoing dance of the planets, Mercury and Venus both reached their greatest elongation or maximum apparent distance from the Sun only a few days ago, on March 29th. Eager to record their celestial accomplishment, ...

2004-04-01

Today, April 1st, astrophysicists have announced a surprising discovery - April Fools Day is more intense on Mars! Though the discovery is contrary to accepted theories of April Fools Day, researchers note that there are several likely causes for ...

2004-03-31 Heidi Schweiker

Lying just at the limit of human perception is a picturesque starfield containing one of the larger open clusters on the northern sky. Spanning an angle larger than the Moon, M39's relatively few stars lie only about 800 light years distant ...

2004-03-30

One of the most spectacular solar sights is a prominence. A solar prominence is a cloud of solar gas held above the Sun's surface by the Sun's magnetic field. Last month, NASA's Sun-orbiting SOHO spacecraft imaged an impressively large ...

2004-03-29

Using oxygen from the air itself, a NASA experimental jet propelled itself past Mach 7 in the atmosphere above the Pacific Ocean this weekend. The small automated X-43A Hyper-X craft was dropped from a huge converted B-52 bomber and then ...

2004-03-28 Brian Lula

Seemingly adrift in a cosmic sea of stars and gas, this delicate, floating apparition is cataloged as NGC 7635 -- The Bubble Nebula. In this wide-angle view, the Bubble nebula lies at the center of a larger complex of shocked glowing gas about ...

2004-03-24

What are those unusual looking dimples? Looking back toward Eagle crater, its landing place on Mars, the robot rover Opportunity has spotted some unusual depressions in the Martian soil. The dimples, visible above on the image left, each ...

2004-03-23

The hot surface of Venus shows clear signs of ancient lava flows. Evidence of this was bolstered by the robot spacecraft Magellan, which orbited Venus in the early 1990s. Using imaging radar, Magellan was able to peer beneath the thick ...

2004-03-22 S. Sposetti

Last week, a small asteroid approached unusually close to the Earth. Asteroid 2004 FH posed no danger, but became bright enough to see with binoculars. Passing only 7 Earth radii away, this asteroid pass was the closest yet that was previously ...

2004-03-21 Polar Image

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just ...