The Ring Nebula’s distinctive shape makes it a popular illustration for astronomy books. But new observations by NASA’s Hubble Space Telescope of the glowing gas shroud around an old, dying, sun-like star reveal a new twist.

“The nebula is not like a bagel, but rather, it’s like a jelly doughnut, because it’s filled with material in the middle,” said C. Robert O’Dell of Vanderbilt University in Nashville, Tenn. He leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of the iconic nebula. The images show a more complex structure than astronomers once thought and have allowed them to construct the most precise 3-D model of the nebula.

The Ring Nebula is about 2,000 light-years from Earth and measures roughly 1 light-year across. Located in the constellation Lyra, the nebula is a popular target for amateur astronomers.

Previous observations by several telescopes had detected the gaseous material in the ring’s central region. But the new view by Hubble’s sharp-eyed Wide Field Camera 3 shows the nebula’s structure in more detail. O’Dell’s team suggests the ring wraps around a blue, football-shaped structure. Each end of the structure protrudes out of opposite sides of the ring.

via NASA – Hubble reveals the Ring Nebula’s true shape.

A close-up view, with the merging galaxies circled. The red data show dust-enshrouded regions of star formation, while green and blue show carbon monoxide gas and starlight, respectively. The blue blobs outside of the circle are galaxies located much closer to us. Image: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

Astronomers have caught two big ancient galaxies in the act of colliding, shedding new light on the role such megamergers played in galactic evolution during the universe’s youth.

The colossal smash up will eventually produce one giant elliptical galaxy, researchers said, suggesting that most such behemoths formed rapidly in this manner long ago, rather than growing slowly over time by gobbling up a series of relatively small galaxies.

“I think at least 90 percent of elliptical galaxies at this mass were formed through this channel,” study lead author Hai Fu, of the University of California, Irvine, told SPACE.com. [Photos of Great Galactic Crashes]

via Rare View of Ancient Galaxy Crash Revealed: Scientific American.

Ligeia Mare, shown here in data obtained by NASA’s Cassini spacecraft, is the second largest known body of liquid on Saturn’s moon Titan. Image credit: NASA/JPL-Caltech/ASI/Cornell › Full image and caption

Saturn’s moon Titan might be in for some wild weather as it heads into its spring and summer, if two new models are correct. Scientists think that as the seasons change in Titan’s northern hemisphere, waves could ripple across the moon’s hydrocarbon seas, and hurricanes could begin to swirl over these areas, too. The model predicting waves tries to explain data from the moon obtained so far by NASA’s Cassini spacecraft. Both models help mission team members plan when and where to look for unusual atmospheric disturbances as Titan summer approaches.

“If you think being a weather forecaster on Earth is difficult, it can be even more challenging at Titan,” said Scott Edgington, Cassini’s deputy project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We know there are weather processes similar to Earth’s at work on this strange world, but differences arise due to the presence of unfamiliar liquids like methane. We can’t wait for Cassini to tell us whether our forecasts are right as it continues its tour through Titan spring into the start of northern summer.”

via NASA – Forecast for Titan: Wild Weather Could Be Ahead.