After 21 years, the Hubble Space Telescope continues to wow the world with mind-bending views of the universe. In celebration of its anniversary, the wonder continues with this gift of a galactic rose formed by a group of interacting galaxies roughly 300 million light years away from Earth.

In the group, known as Arp 273, the upper, larger of the spiral galaxies, UGC 1810, has a disc that is tidally distorted into a rose-like shape by the gravitational pull of the companion galaxy below it, known as UGC 1813, according to an image advisory.

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The uncommon spiral patterns in the large galaxy are a tell-tale sign of interaction between the two galaxies. For example, the large, outer arm appears partially as a ring, a feature that is seen when interacting galaxies pass through one another. This suggests that the smaller companion galaxy actually dived deeply, but off-center, through UGC 1810.

Other notable features in the image include:

• The inner set of spiral arms is highly warped out of the plane, with one of the arms going behind the bulge and combing back out the other side. How they connect isn't precisely known.
• A possible mini spiral may be visible in the spiral arms of UGC 1810 to the upper right. Note how the outermost spiral arm changes character as it passes this third galaxy, from smooth with lots of old stars on one side, to clumpy and extremely blue on the other.
• The swath of blue jewels across the top is the combined light from clusters of intensely bright and hot young blue stars, which glow fiercely in ultraviolet light.
• The smaller galaxy, viewed close to edge-on, shows signs of intense star formation in its nucleus that was perhaps triggered by the encounter with the companion galaxy.

The larger galaxy in the UGC 1810-UGC 1813 pair has a mass that is about five times that of the smaller galaxy. In unequal pairs such as this, the relatively rapid passage of the companion galaxy produces the lopsided structure in the main spiral.

The Hubble Space Telescope was launched from space shuttle Discovery on April 24, 1990. It circles the Earth once every 97 minutes. Though its digital postcards routinely wow the world, it hasn't always been smooth sailing, as noted in this photo trip through the telescope's highs and lows.

NASA astronauts successfully performed a final servicing of the telescope in 2009 that should keep it sending back images for years to come. Meanwhile, the space agency is preparing Hubble's replacement, the James Webb Space Telescope, currently scheduled for launch in 2014. For now, though, let's wish Hubble a happy anniversary and thank it for the galactic rose.

More stunners from Hubble:

• Slideshow: Classic Hubble hits
• Hubble's latest, greatest views revealed
• Cosmic smashup is Hubble's most popular shot
• Slideshow: All-time top-10 astronomy pictures

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John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).

NASA's Solar Dynamics Observatory captured this image today of a massive solar eruption. The source was an active region located just behind the sun's eastern limb, and the coronal mass ejection was not directed at Earth, according to SpaceWeather.com.

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However, the news service notes that "the active region responsible for this blast will emerge over the eastern limb during the next 24 to 48 hours, setting the stage for possible geoeffective solar activity."

The eruption follows close on the heels of another strong solar flare unleashed on Valentine's Day, one that triggered a geomagnetic storm a few days later that disrupted radio communications in China and threatened satellites and power grids.

Scientists expect these events to be more common in the coming years as the sun ramps up activity as part of its 11-year cycle. Solar maximum is predicted for around 2013.

More about solar outbursts:

• Experts warn U.S. must take space storms seriously
• Solar shield to protect power grids from storms
• Solar cycle sparks doomsday buzz

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John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).

For those of us who feel as if there's never enough daylight to get all the stuff done that we need to get done leading up to the holidays, here's a ray of hope: Winter officially begins today in the Northern Hemisphere. That means each day from tomorrow on will get a little bit longer.

The longest night of the year is a good time to marvel at how we light up the night. This iconic image, called "Earth at Night," was stitched together from data gathered by a swarm of Defense Department satellites. The "cloudless" view maps the locations of permanent lights on the Earth's surface. It serves as a handy guide for where we live and the state of development around the world.

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The lights, overlaid on a map for reference, make clear our preference to settle along coastlines and transportation networks. The interstate system in the U.S., for example, appears as a lattice connecting brighter dots. In northern Africa, the Nile River looks like a bright thread through a sea of darkness.

The brightest areas correspond with the most urbanized areas, but not necessarily the most populated. Note the difference, for instance, between Western Europe and China. More than 100 years since the invention of electric light, some regions of the planet remain thinly populated and unlit. Antarctica looks completely dark, as do vast swaths of jungle in Africa and South America.

For more views of Earth from space, check out these past offerings from the Cosmic Log Space Advent Calendar. We've also included links to other online Advent calendars that have been serving up space images daily since the beginning of the month:

• The Cosmic Log Space Advent Calendar so far
• Door 1 for Dec. 1: Shuttle in spotlight
• Door 2 for Dec. 2: 'Alien' lake seen from space
• Door 3 for Dec. 3: Egypt's river of light
• Door 4 for Dec. 4: Tallest building reaches for the sky
• Door 5 for Dec. 5: Russia's dazzling delta
• Door 6 for Dec. 6: Space skipper vs. the world
• Door 7 for Dec. 7: Pearl Harbor from the heavens
• Door 8 for Dec. 8: Listening for E.T.
• Door 9 for Dec. 9: Blast from the past
• Door 10 for Dec. 10: Volcano caught in the act
• Door 11 for Dec. 11: Chronicling climate change
• Door 12 for Dec. 12: Happy St. Lucy's Day
• Door 13 for Dec. 13: Viva Las Vegas
• Door 14 for Dec. 14: Don't wake the volcanoes
• Door 15 for Dec. 15: Stairways to heaven
• Door 16 for Dec. 16: White Christmas in the Midwest
• Door 17 for Dec. 17: Tracks in the sky
• Door 18 for Dec. 18: Amelia Earhart's final resting place?
• Door 19 for Dec. 19: Lunar eclipse as seen from space
• Door 20 for Dec. 20: Our pale blue dot
• The Big Picture at Boston.com: Hubble Advent calendar
• Planetary Society: Solar system Advent calendar
• Zooniverse Advent calendar

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Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).

On Feb. 14, 1990, NASA controllers instructed the Voyager 1 spacecraft to turn around and take one last look at its home planet as it pushed on to the fringe of our solar system. Look closely at the resulting image. That tiny pinpoint of light in the center-right is us – you, me, and everyone else that calls Earth home.

The request came from the late, great astronomer Carl Sagan, one of the world's greatest advocates for advancing the general public's appreciation and understanding of science. He passed away 14 years ago today after a two-year battle with bone-marrow disease.

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The image, called "A Pale Blue Dot," was made when Voyager 1 was about 4 billion miles away. It inspired Sagan's 1994 book "Pale Blue Dot: A Vision of the Human Future in Space." An excerpt puts the image's significance into context:

"It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. It underscores our responsibility to deal more kindly with one another, and to preserve and cherish the only home we've ever known, the pale blue dot."

We leave you to reflect on Sagan's thoughts as we head into the final days of our Cosmic Log Space Advent Calendar. For more views of Earth from space, check out these past offerings. We've also included links to other online Advent calendars that have been serving up space images daily since the beginning of the month:

• The Cosmic Log Space Advent Calendar so far
• Door 1 for Dec. 1: Shuttle in spotlight
• Door 2 for Dec. 2: 'Alien' lake seen from space
• Door 3 for Dec. 3: Egypt's river of light
• Door 4 for Dec. 4: Tallest building reaches for the sky
• Door 5 for Dec. 5: Russia's dazzling delta
• Door 6 for Dec. 6: Space skipper vs. the world
• Door 7 for Dec. 7: Pearl Harbor from the heavens
• Door 8 for Dec. 8: Listening for E.T.
• Door 9 for Dec. 9: Blast from the past
• Door 10 for Dec. 10: Volcano caught in the act
• Door 11 for Dec. 11: Chronicling climate change
• Door 12 for Dec. 12: Happy St. Lucy's Day
• Door 13 for Dec. 13: Viva Las Vegas
• Door 14 for Dec. 14: Don't wake the volcanoes
• Door 15 for Dec. 15: Stairways to heaven
• Door 16 for Dec. 16: White Christmas in the Midwest
• Door 17 for Dec. 17: Tracks in the sky
• Door 18 for Dec. 18: Amelia Earhart's final resting place?
• Door 19 for Dec. 19: Lunar eclipse as seen from space
• The Big Picture at Boston.com: Hubble Advent calendar
• Planetary Society: Solar system Advent calendar
• Zooniverse Advent calendar

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Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).

On Dec. 17, 1903, Orville and Wilbur Wright made history when they piloted a heavier-than air, gasoline-powered biplane for 12 seconds over a distance of 120 feet. More than a century after that first flight, air travel is a routine mode of transportation for millions of people each day. A result of all these people flying may be a discernable bump in global temperatures, according to scientists who study the impact of so-called contrails on the global climate.

Contrails, or condensation trails, form when the hot, humid air from a jet engine mixes with the colder, drier air in the surrounding environment. These streaks can spread out into thin and wispy cirrus clouds. In heavy air-traffic regions, this can increase cloud cover. This image from the Moderate Resolution Imaging Spectrometer (MODIS) on NASA's Terra satellite shows a contrail streaked sky over the Midwestern U.S. Mingled contrails in the top of the image generate cloud cover. Distinct tracks are visible in the southern portion of the image.

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Clouds can have variable effects on the global climate, depending on their extent, thickness and altitude among other factors. They can cool the climate by blocking incoming sunlight, for example, but they can also warm the planet by absorbing energy radiated from the Earth's surface. Thin cirrus clouds are said to have more of a warming effect: their thinness makes them a poor shield against incoming sunlight, but they absorb outgoing radiation that would otherwise escape to space.

In 2004, a NASA-led study published in Journal of Climate concluded that contrail-generated cirrus clouds could be responsible for much of the warming of surface temperatures over the U.S. from 1975 to 1994. This warming, noted Patrick Minnis, a senior research scientist at NASA's Langley Research Center and a co-author of the paper, is an addition to any effect attributed to increasing greenhouse gases.

"This study demonstrates that human activity has a visible and significant impact on cloud cover and, therefore, on climate," he said in a news release about the study. "It indicates that contrails should be included in climate change scenarios."

The effect of contrails on climate change continues to be debated. A widely cited 2002 study published by David Travis at the University of Wisconsin-Whitewater and colleagues in Nature found that the daily temperature range increased by a few degrees in the days following the 2001 terrorist attacks when all air travel was grounded. The finding was seen as support for the idea that contrails warm the Earth. Other papers published more recently, however, suggest that the 20001 effect was due to a shift in low clouds.

Whatever the effect of contrails on climate, the International Ecotourism Society calculates that greenhouse gas emissions from air traffic generate about 10 percent of all greenhouse gases. That's quite a change from the Wright brothers inaugural flight on this day in 1903.

Terra's big-picture view of the contrails over the Midwest is part of the Cosmic Log Space Advent Calendar, which is highlighting images of Earth from space every day until Christmas. For more Advent calendar goodies, check out the Web links below:

• The Cosmic Log Space Advent Calendar so far
• Door 1 for Dec. 1: Shuttle in spotlight
• Door 2 for Dec. 2: 'Alien' lake seen from space
• Door 3 for Dec. 3: Egypt's river of light
• Door 4 for Dec. 4: Tallest building reaches for the sky
• Door 5 for Dec. 5: Russia's dazzling delta
• Door 6 for Dec. 6: Space skipper vs. the world
• Door 7 for Dec. 7: Pearl Harbor from the heavens
• Door 8 for Dec. 8: Listening for E.T.
• Door 9 for Dec. 9: Blast from the past
• Door 10 for Dec. 10: Volcano caught in the act
• Door 11 for Dec. 11: Chronicling climate change
• Door 12 for Dec. 12: Happy St. Lucy's Day
• Door 13 for Dec. 13: Viva Las Vegas
• Door 14 for Dec. 14: Don't wake the volcanoes
• Door 15 for Dec. 15: Stairways to heaven
• Door 16 for Dec. 16: White Christmas in the Midwest
• The Big Picture at Boston.com: Hubble Advent calendar
• Planetary Society: Solar system Advent calendar
• Zooniverse Advent calendar

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Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).