A Giant Globular Cluster in M31

1998-10-17

This cluster of stars, known as G1, is the brightest globular cluster in the whole Local Group of galaxies. Also called Mayall II, it orbits the center of the largest nearby galaxy: M31. G1 contains over 300,000 stars and is almost as old as the ...

Io Aurora

1998-10-16

Alluring aurora surrounding Io (eye-oh) appear as a ghostly glow while the volcanic moon orbits within Jupiter's dark shadow. Gas giant Jupiter is off to the right of this image, recorded in May by the robot Galileo spacecraft's solid state ...

A Great Day For SOHO

1998-10-15

The last 10 days have been great days for SOHO, the space-based SOlar and Heliospheric Observatory. Contact was completely lost with this international research spacecraft over 3 months ago but recovery teams have reacquired control of SOHO and, ...

The World's Largest Ozone Hole

1998-10-14

It's back, and it's bigger than ever. The ozone hole that has been a cause of concern in recent years has again reformed over Earth's South Pole. The seasonal recurrence of the ozone hole was expected, although the size of the hole has never ...

In the Center of the Dumbbell Nebula

1998-10-13

Here's part of the Dumbbell Nebula that you can't see through binoculars. To see this, we suggest a sophisticated spectrograph attached to a telescope with an 8-meter aperture. Pictured above is the central part of the Dumbbell Nebula, also ...

The Hubble Deep Field in Infrared

1998-10-12

Galaxies this faint have never been seen before. In 1996 the Hubble Space Telescope (HST) created one of the most famous pictures of modern astronomy, the Hubble Deep Field (HDF). Now HST has returned to a piece of the HDF for a long exposure by ...

Resolving Mira

1998-10-11

Most stars appear only as points of light. Early last year, Betelgeuse became the second star, after our Sun, to have it surface resolved. Later last year, Mira was added to the list. Mira A is a red giant star undergoing dramatic pulsations, ...

M27: Not A Comet

1998-10-09

While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely not comets. So what is it? Well, 20th century astronomers would ...

Far Side of the Moon

1998-10-08

Locked in synchronous rotation, the Moon always presents its well-known near side to Earth. But from lunar orbit, Apollo astronauts also grew to know the Moon's far side. This sharp picture from Apollo 16's mapping camera shows the eastern edge ...

Ocean Planet Pole To Pole

1998-10-07

The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument onboard the orbiting SeaStar spacecraft can map subtle differences in Earth's ocean color. These North (left) and South Pole projections are based on SeaWiFS measurements made between ...