Happy birthday, Hubble

There's plenty to celebrate today as the Hubble Space Telescope turns 19 years old: The billion-dollar orbiting observatory is still in business, even though some people thought it should have failed by now. And after years and months of delay, it looks as if help is finally on the way. The shuttle Atlantis is set to deliver hundreds of millions of dollars' worth of belated birthday gifts next month.

Since the telescope's launch aboard the shuttle Discovery on April 24, 1990, Hubble has traveled 2.8 billion miles in space during more than 100,000 orbits around the earth. More than 570,000 pictures have been taken of about 29,000 celestial objects. The data transmissions sent back from Hubble add up to almost 39 trillion bytes - twice as much as all the data contained in all the books in the Library of Congress.

You can find these and other fun facts on the Space Telescope Science Institute's Hubble trivia page. You'll also find a rundown of Hubble's top discoveries to date - including insights into the nature of dark matter and dark energy, the speed-up of our expanding universe and the development of galaxies, stars and planets.

Just in the past month, Hubble has delivered a new batch of beauties, including its 19th-anniversary picture of a galactic "fountain of youth," a stunning view of an intergalactic smashup and a "People's Choice" picture of a three-galaxy traffic jam.

And there's much more to come, thanks to the Atlantis mission now due for launch as early as May 11: If all goes as planned, two new and improved instruments will be installed, two more will be fixed, and the telescope will be outfitted with new batteries and gyroscopes to keep it on track until the 2013-2014 time frame.

In honor of Hubble's birthday, we've turned this week's Sci-Q test into a Hubblefest. We're also serving up a fresh selection of cosmic images from the past month, including a couple of Hubble's highlights. If you're looking for bigger versions of our Month in Space Pictures, here's the lineup:

• Room with a view: NASA's Human Spaceflight Web site has a nice selection of "billion-dollar photographs" showing the international space station.
• Green space: The Joint Astronomy Center shows off the Orion Molecular Cloud.
• Emerald Isle: NASA's MODIS Web puts Ireland front and center. Note that the picture was taken on the day after St. Patrick's Day.
• Rings revealed: The Cassini imaging team's CICLOPS Web site has Saturn and its rings covered. By the way, The Boston Globe's "Big Picture" made a big deal out of Cassini's images this week.
• New spy in the sky: Feast your eyes on a bigger view of India's satellite launch.
• Bridge breakup: NASA's Earth Observatory focuses on the collapse of Antarctica's Wilkins Ice Bridge.
• Heavenly crash: We've already mentioned the galaxy-cluster collision. If you need a hint to help with the Sci-Q test, here's another Web link.
• Touchdown: You'll find lots of pictures of Discovery's landing on NASA's Human Spaceflight site (keep clicking through the last pages).
• Billionaire's space odyssey ends: NASA's Human Spaceflight, again, for the win. Or this one, come to think of it.
• Weird Mars: It wouldn't be "Month in Space Pictures" without a cool shot from the HiRISE camera on NASA's Mars Reconnaissance Orbiter.
• Vietnam's rice bowl: The European Space Agency's Envisat probe focuses on the mighty Mekong Delta.
• Past and present: Get a good look at NASA's next spaceship.
• Pair of pinwheels: This picture of interweaved galaxies is one of Hubble's biggest crowd-pleasers from the past month.
• North Korea's launch: DigitalGlobe has the big picture when it comes to Pyongyang's latest blastoff.
• South Korea's answer: You can read the lettering on this view of South Korea's KSLV-1 rocket.
• Blue Lagoon: The big picture of Atafu Atoll from NASA's Earth Observatory will almost make you forget about the discord on the Korean Peninsula.
• Spiders on Mars! HiRISE's view of a "starburst spider" on Mars looks only slightly less eerie when you see it close up.
• A river runs through it: DigitalGlobe's view of the North Dakota flooding looks stark in black and white - and the contrast with pre-flood imagery is stark as well.
• Hand of God:This picture from Chandra generated a lot of debate here on Cosmic Log last week.
• Martian panorama: NASA's Mars rover Web site has bigger versions of the Spirit rover's panorama. Get out the 3-D glasses!
• Flying saucer: The weird galaxy NGC 7049 stars in another stunning image from Hubble, highlighted by the European Space Agency's Hubble team.
• Double shuttles: Get a good look at this view of Atlantis and Endeavour on their launch pads, and check out other double-shuttle images from Kennedy Space Center's media archive. After next month, you may never see this again.

We have plenty more to see when it comes to Hubble highlights: Check out our slideshow of Hubble's greatest hits, our must-see audio slideshow about fixing Hubble through the years, and our "Long View" interactive guide to Hubble.

Correction for 9:30 p.m. ET: I've fixed the reference to the reading on Hubble's odometer after several commenters pointed out my regrettable error. Thanks for keeping me honest.