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Holiday greetings from space

While some people are still finishing up the Thanksgiving turkey leftovers, the Hubble Heritage Team has already sent out its holiday card for this year: a spiral galaxy festooned with stars like a Christmas wreath. NASA's other "Great Observatories" have also delivered some colorful views this week - and if you're still working on your season's greetings, you'll find some out-of-this-world suggestions on the Web.

NASA / ESA / Hubble Heritage
The Hubble Space Telescope's view of the spiral
galaxy M74 looks like a festive holiday wreath.
Click on the image for a bigger version.


Today's picture from the Hubble Space Telescope shows the galaxy M74, also known as NGC 628, which is pointed nearly face-on toward Earth, 32 million light-years away in the constellation Pisces. Astronomers estimate that the galaxy has about 100 billion stars, making it slightly smaller than our own Milky Way.

Hubble's image is based on data collected in 2003 and 2004 using the telescope's Advanced Camera for Surveys. Additional data from the Canada-France-Hawaii Telescope was used to fill in a gap in the Hubble view.

The image is more sparkly than you might see in person, because the colors have been chosen to reflect infrared as well as visible-light wavelengths. The ornaments on the galactic wreath are clusters of young blue stars and glowing pink regions of ionized hydrogen. Lanes of dust and stars swirl out from the galaxy's bright center.

M74's picture-perfect spiral was first spotted back in 1780 and has been a popular target for astronomers ever since - this 2001 picture from the Gemini Observatory provides yet another stunning perspective.

The beauty of Hubble is that it's so easy to share them with others. HubbleSite's Astronomy Printshop makes it easy for you to produce high-quality prints of the space telescope's greatest hits.

If you head on over to the European Space Agency's Hubble Web site, you'll find a selection of preformatted postcards suitable for printing. Just scrawl your holiday greeting on the back and you're good to go. There are also files for posters and calendars (although 2008 hasn't been posted yet). The site even has an online store (although the goods will have to be shipped from Germany).

NASA / CXC / Middlebury / NOAO
The large picture shows a wide-field view of the Puppis A supernova remnant in X-ray and optical wavelengths, with a close-up image from Chandra at right, showing
the position of the neutron star RX J0822-4300 in 1999 and 2005.


The scientists behind the Chandra X-Ray Telescope haven't exactly sent a card, but the "cosmic cannonball" shown in their latest offering could serve as a virtual holiday ornament. The cannonball is actually a neutron star called RX J0822-4300 that was ejected by a supernova explosion about 3,700 years earlier.

When scientists compared Chandra imagery from 1999 and 2005, they determined that the star was moving more than 3 million miles (5 million kilometers) an hour, making it one of the fastest-moving stars ever observed. "At this rate, RX J0822-4300 is destined to escape from the Milky Way after millions of years, even though it has only traveled about 20 light-years so far," the Chandra team said in Wednesday's image advisory.

Looking at the big picture, astronomers found that most of the oxygen-rich debris from the supernova blast was moving toward the left, while the cannonball was moving toward the right. "The oxygen clumps are believed to be massive enough so that momentum is conserved in the aftermath of the explosion, as required by fundamental physics," the Chandra team said.

For more ornaments from the Chandra Web site, check out this gallery of e-cards specially designed for the season's holidays. You'll also find a variety of printable materials, including puzzles, posters and pictures.

NASA / JPL-Caltech / UIUC
The picture at left shows the area around the developing sunlike star L1157 in
visible light. At right, the Spitzer infrared image looks within the haze to see
jets of gas streaming outward from the star, which itself is still shrouded in dust.


Today's image from NASA's third Great Observatory, the Spitzer Space Telescope, shows a solar system's "baby picture" in reddish and greenish Christmas hues. Those colors reflect different wavelengths of infrared light emitted by giant jets of gas streaming out from the star. The green and white areas are the warmest (about 212 degrees Fahrenheit, or 100 degrees Celsius), while the red and orange streaks represent cooler material, in the range of zero degrees on both temperature scales.

The dark streak running through the center of the picture is thought to be a hazy envelope of dust surrounding the infant star. The researchers speculate that our own solar system might have looked much like this in its early days.

"Some theories had predicted that envelopes flatten as they collapse onto their stars and surrounding planet-forming disks, but we hadn't seen any evidence of this until now," Leslie Looney of the University of Illinois at Urbana-Champaign said in a university news release.

Looney is the lead author of a report about the observations appearing in the Dec. 1 issue of Astrophysical Journal Letters. Other authors include John Tobin of the University of Michigan at Ann Arbor, and Woojin Kwan of the University of Illinois.

The Spitzer Web site offers a variety of printable materials suitable for geeks bearing gifts, including a 2008 calendar. And you can graze through Spitzer's image gallery for do-it-yourself holiday e-cards. Don't forget to send me one!