Although the magnitude 8.7 Nias-Simeulue earthquake of March 28, 2005, was technically an aftershock, the temblor nevertheless killed more than 2,000 people in an area that had been devastated just three months earlier by the December 2004, magnitude 9.1 earthquake. Now, data returned from instruments in the field provide constraints on the behavior of dangerous faults in subduction zones, fueling a new understanding of basic mechanics controlling slip on faults, and in turn, improved estimates of regional seismic risk.

To paraphrase a certain young lady from literature, the tenth planet Xena is getting curiouser and curiouser. Data released today by the Space Telescope Science Institute reveals that Xena is about 5 percent larger than Pluto, which means that it must be the most reflective planet in the solar system.

Next time you're brushing your teeth in the morning, give a thought to biofilms, the complex communities of bacteria that form the slippery scum you're scouring off your teeth, along with the slime on river rocks, the gunk in clogged drains, and filmy coatings on just about any surface, anywhere, that's exposed to water.

A mere three months after the giant Sumatra-Andaman earthquake and tsunami of December 2004, tragedy struck again when another great earthquake shook the area just to the south, killing over 2,000 Indonesians. Although technically an aftershock of the 2004 event, the 8.7-magnitude Nias-Simeulue earthquake just over a year ago was itself one of the most powerful earthquakes ever recorded. Only six others have had greater magnitudes.

The Sumatra-Andaman earthquake of December 26, 2004, was one of the worst natural disasters in recent memory, mostly on account of the devastating tsunami that followed it. A group of geologists and geophysicists, including scientists at the California Institute of Technology, has delineated the full dimensions of the fault rupture that caused the earthquake.

In 2005, after seven years scanning half the sky for planets in our solar system beyond Pluto and discovering dozens of large new objects, Michael E. Brown and his colleagues finally found 2003 UB313, aka "Xena," the first object larger than Pluto, and the first that might be called a new planet.

In a new study that provides a novel way of looking at our solar system's past, a group of planetary scientists and geochemists announce that they have found evidence on Earth of an asteroid breakup or collision that occurred 8.2 million years ago.

The beautiful valleys of the southern Coast Mountains of British Columbia exist for us to enjoy today because of glacial action in the past. Geologists know, for example, that a giant glacier carved a deep groove in the mountain range to form the present-day Klinaklini Valley. But how fast the cutting actually took place, and when, has hitherto been conjecture.

One of the most powerful computer clusters in the academic world has been created at the California Institute of Technology in order to unlock the mysteries of earthquakes.

The deep-sea corals of the North Atlantic are now recognized as "archives" of Earth's climatic past. Not only are they sensitive to changes in the mineral content of the water during their 100-year lifetimes, but they can also be dated very accurately.