Sunspots: Magnetic Depressions

1998-03-22

Our Sun has spots! These spots appear dark in photographs like the one above, but in fact sunspots are quite bright - they are just dark compared to the rest of the Sun. Sunspots are about the size of the Earth and frequently occur in groups, as ...

The Gamma Ray Sky

1998-03-21

What if you could "see" gamma rays? If you could, the sky would seem to be filled with a shimmering high-energy glow from the most exotic and mysterious objects in the Universe. In the early 1990s NASA's orbiting Compton Observatory, produced ...

Mars: Ridges Near The South Pole

1998-03-20

No, it's not breakfast ... but looking down from an orbiting spacecraft, the odd intersecting ridges covering this area of Mars do present a waffle-like appearance. The cause of the ridge pattern is unknown but it suggests that more complex ...

Mars: A Canyon's Edge

1998-03-19

High resolution Mars Global Surveyor images were combined with Viking Orbiter color data to produce this stunning, detailed view of a Martian canyon's edge. The area pictured is about 6 miles wide and represents a tiny part of the northern edge ...

Interstellar Dust-Bunnies of NGC 891

1998-03-18

What is going on in NGC 891? This galaxy appeared previously to be very similar to our own Milky Way Galaxy: a spiral galaxy seen nearly edge-on. However, recent high-resolution images of NGC 891's dust show unusual filamentary patterns ...

Clouds Over Tharsis on Mars

1998-03-17

When and where do clouds form on Mars? The Mars Global Surveyor spacecraft currently orbiting Mars is finding out. Photographs released last week showed clouds forming above Tharsis, a huge bulge on Mars about 4000 kilometers across and 7 ...

Asteroids in the Distance

1998-03-16

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak ...

Unusual M82: The Cigar Galaxy

1998-03-15 CfA

Something strange happened to this galaxy, but what? M82 is a nearby galaxy in the group of galaxies dominated by itself, M81, and NGC 3077. M82 is thought by some to be limping away from a close encounter with M81. This galactic collision ...

A Spiral Galaxy Gallery

1998-03-14

A progression of beautiful spiral galaxies is illustrated above with three photographs from NASA's Ultraviolet Imaging Telescope (UIT). Flying above the Earth's obscuring layer of atmosphere on the Space Shuttle Columbia during the Astro-1 ...

Asteroids

1998-03-13

No asteroid or comet is known to be on a collision course with Earth. The asteroid designated 1997 XF11 had been predicted to come uncomfortably close, but new estimates place its passing beyond the orbit of the Moon. This earth-approaching ...