Auroras Over Both Earth Poles
Auroras in the north and south can be nearly mirror images of each other. Such mirroring had been suspected for centuries but dramatically confirmed only last month by detailed images from NASA's orbiting Polar spacecraft. Pictured above, a ...
A Gravity Map of Earth
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 ...
Is Mystery Object an Orphan Afterglow?
What is that unusual object? Astronomers can identify most objects that are imaged on the sky, but not all. Pictured above is one that currently defies classification. Attributes of the object include that it has unusual colors, appears to be ...
An Annotated Leonid
The 1998 Leonids Meteor Shower was one of the most photographed meteor events in history. Patient observers saw bright meteors streak across dark skies every few minutes, frequently leaving fading trails stretching across the sky. High above ...
Lunar Dust and Duct Tape
Why is the Moon dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, the long history of micrometeorite bombardment has blasted away at the rocky surface creating a layer of powdery lunar soil or regolith. ...
SOHO Comet 367: Sungrazer
The most prolific comet discovering instrument in history rides aboard the sun-staring SOHO spacecraft, 1.5 million kilometers sunward of planet Earth. Of course, most of these SOHO comets have been sungrazers - like the one illustrated in the ...
Under A Sunspot
At the Sun's surface, sunspots are known to be dark, planet-sized regions of intense magnetic fields. But what lies below? Using observations from the Michelson Doppler Imager (MDI) instrument aboard the space-based SOHO observatory, astronomers ...
A Sun Pillar in Red and Violet
Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada, two amateur photographers noticed an unusual red column of light rise mysteriously from a setting sun. During the next few minutes, they were able to capture the ...
In the Center of Spiral Galaxy M83
What's happening at the center of spiral galaxy M83? Just about everything, from the looks of it. M83, visible in the inset image on the upper left, is one of the closest spiral galaxies to our own Milky Way Galaxy and from a distance of 15 ...
Aurora Over Winnipeg
What's happening above that city? The city is Winnipeg, Canada, and the phenomenon is aurora. These past few months have been active ones for our Sun, producing several coronal mass ejections (CMEs) of particles that have swept past our Earth ...
