October 26th, 2011
01:38 PM ET

All That Remains

"Infrared images from NASA's Spitzer Space Telescope and the Wide-field Infrared Survey Explorer, or WISE, were combined in this image of RCW 86, the dusty remains of the oldest documented example of an exploding star, or supernova. It shows light from both the remnant itself and unrelated background light from our Milky Way galaxy. The colors in the image allow astronomers to distinguish between the remnant and galactic background, and determine exactly which structures belong to the remnant.

Dust associated with the blast wave of the supernova appears red in this image, while dust in the background appears yellow and green. Stars in the field of view appear blue. By determining the temperature of the dust in the red circular shell of the supernova remnant, which marks the extent to which the blast wave from the supernova has traveled since the explosion, astronomers were able to determine the density of the material there, and conclude that RCW 86 must have exploded into a large, wind-blown cavity."

Source: NASA

Filed under: Light up the screen
Dinosaurs migrated long distances, says new study
These dinosaur tooth fossils have horizontal marks where enamel was removed for analysis by Colorado College researchers.
October 26th, 2011
01:00 PM ET

Dinosaurs migrated long distances, says new study

Like many birds and mammals today, ancient plant-eating dinosaurs migrated hundreds of miles each year as seasons changed, according to a study published online Wednesday by the journal Nature.

Scientists have long suspected that camarasaurus - a 50-foot-long, 20-ton dinosaur that lived 145 million years ago during the late Jurassic Period - migrated.

But what really surprised scientists was how far these big lizards walked: a six-month, 186-mile trek from lowlands to the mountains and then back again.

"That's a lot of  walking to do over the course of a year," said the study's lead scientist, Henry Fricke of Colorado College.

The research touches on key questions among dinosaur experts: How did these giant beasts behave, and why were they so big?

Fossilized teeth and chemicals called oxygen isotopes may have unlocked a few clues.

Fricke and his team spent four years analyzing oxygen isotopes in fossilized camarasaurus teeth found in Wyoming and Utah.

Here's a basic idea of how it worked. Water across the ancient landscape contained specific ratios of two isotopes: oxygen 18, which has eight protons and 10 neutrons in its nucleus, and oxygen 16, which has eight protons and eight neutron in its nucleus.  Researchers were able to track locations where the dinosaurs drank their water by examining the isotopes built up in the fossilized tooth enamel, like a "tiny tape recorder of what animals were drinking," Fricke said. From this data, scientists tracked the dinosaurs from lowlands in what is now Wyoming and Utah to mountainous regions to the west.

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Filed under: Dinosaurs • Discoveries • News • On Earth
October 26th, 2011
11:29 AM ET

Spectacular aurora borealis

If you’ve ever seen the aurora borealis, you know what a spectacular sight it can be. You also know it’s all about location, location, location. The northern lights are generally only visible in the more northern latitudes, but this week, many people were seeing these amazing displays as far south as Georgia and Alabama. Why was this aurora event visible to so many?

The chain of events that caused the lights started as early as 9:36 p.m. on Friday, with the occurrence of a Coronal Mass Ejection. These CMEs are large eruptions of positively charged ions and negatively charged electrons from the sun that travel through space, sometimes heading toward the Earth. They can occur at any time, but typically, these events are more common during periods of high solar activity. From now until 2013, there will be a solar maximum, or a peak in solar activity, meaning we will likely see more events like these CMEs, as well as sunspots and solar flares.


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