According to new research from geologists, the Earth's core rotates just a little bit faster - about 1 degree per year - than the crust of the planet. The scientists took advantage of historical records for "earthquake twins" near the South Sandwich Islands. These are quakes that occurred in virtually the same spot with the same magnitude, but were years apart. As the seismic waves passed through the Earth, they were bent as they passed through the Earth's iron core. The shape of this bending has changed over time, indicating the core's faster rotation.

Larry took this close picture of comet Hale-Bopp from Germantown Hills, Illinois. This image was taken with a Nikon 35mm camera and a 200mm lense riding piggyback on the guided telescope.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Joseph Caruana took this picture of M104. Joseph used a Meade DSI PRO to take this image.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Shevill Mathers took this beautiful picture of an aurora beam on the 24th, August from Tasmania, Australia.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Michael Good took this picture of M57 Ring Nebula with Galaxy IC1296 from Roanoke, Virginia. Michael used a Meade 10" LX200 classic.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

Wait, don't throw that garbage bag away. It might come in handy if you wanted to build a spaceship. At least, that's what NASA scientists working on new spacecraft materials are proposing. They've invented a new polyethylene-based material called RXF1 that's even stronger and lighter than aluminum. A plastic material like this is actually surprisingly protective against solar flares and cosmic rays since it doesn't produce "secondary radiation", like aluminum.

Amateur astronomers are helping unravel mysteries about about a strange binary star system. Even though space and ground-based observatories will be observing the cataclysmic variable star AE Aqr, astronomers are calling on amateurs to make additional observations as well. AE Aqr consists of a red dwarf feeding material to a white dwarf companion star. Instead of striking the white dwarf, this material is flung out of the system by the star's intense magnetic field. Amateurs are being asked to observe this object every night until September 3.

In the constellation of Pisces, 100 million light-years from Earth, two galaxies are smashing together in a dramatic demonstration of our far future: when the Milky Way collides with the Andromeda Galaxy. This image of NGC 520 was taken with the Gemini North Telescope on the evening of July 13-14, 2005. It's possible to see dark dust lanes and a long trail of stars thrown out by the cosmic collision.

Cassini captured this image of Titan's bright side during its recent flyby on August 21, 2005. The photograph was taken when Cassini was 213,000 kilometers (132,000 miles) from Titan. This picture is a natural image, which shows the thick smoggy atmosphere that normally blocks views of the moon's surface.

Scientists always function on the cutting edge of their field. New discoveries, new processes, and new events highlight a challenging and sometimes rewarding career. However, scientists share this edge with others. For example, authors of science fiction novels regularly create new worlds, new physics and new societies that allow us to contemplate our own existence and guide our scientific studies. Robert Markley in his book Dying Planet captures nuances of both these fields in reviewing how research and literature about the planet Mars have been busily advancing our wonder, questioning and knowledge.

Rick Stankiewicz took this picture of the Moon and Mercury on the 22th, March 2004 from his backyard near Keene, Ontario, Canada. This image was taken with a Nikon Coolpix 995.

Do you have photos you'd like to share? Post them to the Universe Today astrophotography forum or email them to me directly, and I might feature one in Universe Today.

NASA scientists think they've developed a strong case that liquid water created the strange gullies discovered on Mars a few years ago. These gullies might indicate underground sites of water, and could be a good place to search for life. Although Mars' environment is too cold, dry and low pressure to support liquid water, it could last a little while as it escaped from an underground reservoir. The lack of debris fields at the ends of these gullies suggests the water froze or evaporated before it reached the bottom.

Around 251 million years ago, something happened to the Earth's climate that wiped out 90-95% of marine life and 70% of terrestrial life. Scientists at the National Center for Atmospheric Research (NCAR) have developed a computer model that demonstrates that rapid increases in carbon dioxide belched out of volcanoes did the trick. Temperatures were 10 to 30 degrees Celsius (18 to 54 degrees Fahrenheit) higher than they are today, which broke a cycle that pulled carbon dioxide out of the atmosphere.

On the night of August 4, 2005, legendary amateur astronomer Reverend Robert Evans discovered a supernova just north of galaxy NGC 1559. In the days that followed, astronomers classified it as a Type 1A supernova, the kind created when a white dwarf constantly pulls material from a larger stellar partner; eventually it can't hold any more and explodes as a supernova. These kinds of supernovae explode with a set amount of energy, so astronomers can use them to measure distance to galaxies.

Climate scientists are predicting that the Arctic Ocean could be completely free of ice during the summer within 100 years thanks to rising ocean temperatures. Several feedback mechanisms will also accelerate these changes. For example, the white ice reflects radiation from the Sun, and contributes to lower temperatures. As the ice melts, the region becomes darker and the melting should speed up.

Greetings, fellow SkyWatchers! I'd like to thank all of you who took the time to write to me about this year's Mars apparition and this week we'll look at both the "fact" and the "fiction". Now it's time to start our explorations as we check in on the planets, visit the "Lagoon", have a look at the M25, journey to the "Small Sagittarius Star Cloud", and track down the "Trifid". So, get your telescopes and binoculars ready, because...

Here's what's up!

As it passed through the ring plane, Cassini took this amazing photograph of Saturn's moon Pandora, hovering just above the rings. Saturn's F ring is thinly visible just above the main rings which are the dark line across the picture. You can also see some variation in the height of Saturn's cloud tops in this photograph, which look like ripples in an ocean. Pandora is only 84 km (52 miles across).

Researchers from the University of Michigan are predicting that when asteroid 99942 Apophis (2004 MN4) swings past the Earth in 2029, it will get so close that astronomers should learn a tremendous amount about how the Earth's gravity can shift asteroid orbits. The researchers are hoping that a space agency will put instruments on the surface of the asteroid to measure seismic data, similar to the way seismologists use earthquakes to probe the Earth's interior.

This is part 2 of an edited transcript of a presentation given by Pamela Conrad, a NASA astrobiologist who has been traveling to the ends of the Earth to study the extremes of life. In this second part, Conrad continues her explanation of how studying cold deserts here on Earth can aid the search for life in our Solar System. Part 1 is available here.

A researcher from the University of Toronto has found unexpectedly young material in meteorites, challenging theories about early events in the formation of the Solar System. A paper published in Nature reports that key minerals called chondrules have been found in meteorites that formed much later than the initial nebula that collapsed to form our Solar System. Instead, these chodrules were probably created when two newly forming planets smashed together.