December 25, 2013
Day 25 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos. The Hubble Ultra Deep Field. Almost none of the objects visible in this image are within our own galaxy, the Milky Way. Instead, practically every smudge, dot or spiral you see here is an entire galaxy, each composed of billions of stars. In late 2003, scientists pointed Hubble at a relatively dim patch of sky, and just opened up the shutter, leaving it open for more than one million seconds (just over 11 days). The result was the Ultra Deep Field, a snapshot of more than 10,000 previously unkown galaxies visible within a tiny patch of our night sky. No other image has ever demonstrated so powerfully the unimaginable vastness of our universe, or the wonders yet to be discovered. (NASA, ESA, S. Beckwith, STScI and the HUDF Team)

Thanks so much for being a part of this year’s Hubble Advent Calendar! Merry Christmas, Happy New Year, and a heartfelt wish for Peace on Earth in 2014!

-Alan

Day 25 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos. The Hubble Ultra Deep Field. Almost none of the objects visible in this image are within our own galaxy, the Milky Way. Instead, practically every smudge, dot or spiral you see here is an entire galaxy, each composed of billions of stars. In late 2003, scientists pointed Hubble at a relatively dim patch of sky, and just opened up the shutter, leaving it open for more than one million seconds (just over 11 days). The result was the Ultra Deep Field, a snapshot of more than 10,000 previously unkown galaxies visible within a tiny patch of our night sky. No other image has ever demonstrated so powerfully the unimaginable vastness of our universe, or the wonders yet to be discovered. (NASA, ESA, S. Beckwith, STScI and the HUDF Team)

Thanks so much for being a part of this year’s Hubble Advent Calendar! Merry Christmas, Happy New Year, and a heartfelt wish for Peace on Earth in 2014!

-Alan

December 24, 2013
Day 24 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually.  In February of 1997, the Hubble Space Telescope begins its separation from the Space Shuttle Discovery following its release after a servicing mission. This 13.2 m (43.5 ft), 11,110 kg (24,500 lb) telescope has been in low Earth orbit for nearly 24 years now, returning thousands of images and priceless data to scientists here on Earth. Barring any major trouble, engineers believe Hubble could remain operational for years, possibly past the launch the James Webb Space Telescope, scheduled for launch in 2018. (NASA)

Day 24 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. In February of 1997, the Hubble Space Telescope begins its separation from the Space Shuttle Discovery following its release after a servicing mission. This 13.2 m (43.5 ft), 11,110 kg (24,500 lb) telescope has been in low Earth orbit for nearly 24 years now, returning thousands of images and priceless data to scientists here on Earth. Barring any major trouble, engineers believe Hubble could remain operational for years, possibly past the launch the James Webb Space Telescope, scheduled for launch in 2018. (NASA)

December 23, 2013
Day 23 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Disk galaxy NGC 5866, viewed edge-on, about 50 million light years away from Earth. A dust disk runs along the edge of the galaxy, past which you can see its structure: a subtle, reddish bulge surrounding a bright nucleus, a blue disk of stars running parallel to the dust lane, and a transparent outer halo. Background galaxies that are millions to billions of light-years farther away are also seen through the halo. (NASA, ESA, and The Hubble Heritage Team)

Day 23 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Disk galaxy NGC 5866, viewed edge-on, about 50 million light years away from Earth. A dust disk runs along the edge of the galaxy, past which you can see its structure: a subtle, reddish bulge surrounding a bright nucleus, a blue disk of stars running parallel to the dust lane, and a transparent outer halo. Background galaxies that are millions to billions of light-years farther away are also seen through the halo. (NASA, ESA, and The Hubble Heritage Team)

December 22, 2013
Day 22 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually.  An animation (click through to see animation), showing the light echoes bouncing around variable star RS Puppis over a period of five weeks. as the star grows brighter and dimmer as it pulsates. These pulsations have created a stunning example of a phenomenon known as a light echo, where light appears to reverberate through the murky environment around the star. RS Puppis is a type of variable star known as a Cepheid variable, with a fairly long period, varying in brightness by almost a factor of five every 40 or so days. (NASA, ESA, and the Hubble Heritage Team)

Day 22 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. An animation (click through to see animation), showing the light echoes bouncing around variable star RS Puppis over a period of five weeks. as the star grows brighter and dimmer as it pulsates. These pulsations have created a stunning example of a phenomenon known as a light echo, where light appears to reverberate through the murky environment around the star. RS Puppis is a type of variable star known as a Cepheid variable, with a fairly long period, varying in brightness by almost a factor of five every 40 or so days. (NASA, ESA, and the Hubble Heritage Team)

December 21, 2013
Day 21 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Planetary nebula NGC 6302, better known as the Butterfly Nebula, is made up of roiling cauldrons of gas heated to nearly 20,000 degrees Celsius. The gas is tearing across space at more than 950 000 kilometers per hour - fast enough to travel from Earth to the Moon in 24 minutes. A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. (NASA, ESA and the Hubble SM4 ERO Team)

Day 21 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Planetary nebula NGC 6302, better known as the Butterfly Nebula, is made up of roiling cauldrons of gas heated to nearly 20,000 degrees Celsius. The gas is tearing across space at more than 950 000 kilometers per hour - fast enough to travel from Earth to the Moon in 24 minutes. A dying star that was once about five times the mass of the Sun is at the center of this fury. It has ejected its envelope of gases and is now unleashing a stream of ultraviolet radiation that is making the cast-off material glow. (NASA, ESA and the Hubble SM4 ERO Team)

December 20, 2013
Day 20 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually.  The Luminous Red Galaxy in the center of the bullseye here has an unusually large mass, containing about ten times the mass of the Milky Way. The blue horseshoe shape is a distant galaxy that has been magnified and warped into a nearly complete ring by the strong gravitational pull of the massive foreground galaxy. This “Cosmic Horseshoe” is one of the best examples of an Einstein Ring — gravitational lensing where the alignment is perfect, allowing the light from distant galaxies to warp around nearer massive galaxies into a circular shape. The distant blue galaxy is about 10 billion light years away. (ESA/Hubble, NASA)

Day 20 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. The Luminous Red Galaxy in the center of the bullseye here has an unusually large mass, containing about ten times the mass of the Milky Way. The blue horseshoe shape is a distant galaxy that has been magnified and warped into a nearly complete ring by the strong gravitational pull of the massive foreground galaxy. This “Cosmic Horseshoe” is one of the best examples of an Einstein Ring — gravitational lensing where the alignment is perfect, allowing the light from distant galaxies to warp around nearer massive galaxies into a circular shape. The distant blue galaxy is about 10 billion light years away. (ESA/Hubble, NASA)

December 19, 2013
Day 19 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. A small section of the Carina Nebula, a star-forming region about 7,500 light-years from Earth in the southern constellation of Carina. Infant stars blaze with a ferocity so severe that the radiation emitted carves away at the surrounding gas, sculpting it into strange structures. The dust clumps towards the upper right of the image, looking like ink dropped into milk, were formed in this way. It has been suggested that they are cocoons for newly forming stars. The brightest stars in the image are in the much closer to us, and are not actually part of the Carina Nebula. (ESA/Hubble, NASA )

Day 19 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. A small section of the Carina Nebula, a star-forming region about 7,500 light-years from Earth in the southern constellation of Carina. Infant stars blaze with a ferocity so severe that the radiation emitted carves away at the surrounding gas, sculpting it into strange structures. The dust clumps towards the upper right of the image, looking like ink dropped into milk, were formed in this way. It has been suggested that they are cocoons for newly forming stars. The brightest stars in the image are in the much closer to us, and are not actually part of the Carina Nebula. (ESA/Hubble, NASA )

December 18, 2013
Day 18 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Spiral galaxy NGC 634 was discovered back in the nineteenth century by French astronomer Édouard Jean-Marie Stephan. It is about about 120,000 light years across, and lies 250 million light years away in the Triangulum constellation. Other, more distant galaxies can be seen in the background as well as through the galaxy. (ESA/Hubble, NASA)

Day 18 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Spiral galaxy NGC 634 was discovered back in the nineteenth century by French astronomer Édouard Jean-Marie Stephan. It is about about 120,000 light years across, and lies 250 million light years away in the Triangulum constellation. Other, more distant galaxies can be seen in the background as well as through the galaxy. (ESA/Hubble, NASA)

December 17, 2013
Day 17 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. IRAS 23166+1655 is an unusual pre-planetary nebula, a celestial spiral around the star LL Pegasi. The spiral pattern suggests a regular periodic origin for the nebula’s shape. The material forming the spiral is moving outwards a speed of about 50.000 km/hour and, by combining this speed with the distance between layers, astronomers calculate that the shells are each separated by about 800 years. The spiral is thought to arise because LL Pegasi is a binary system, with the star that is losing material and a companion star orbiting each other. (ESA/NASA, R. Sahai)

Day 17 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. IRAS 23166+1655 is an unusual pre-planetary nebula, a celestial spiral around the star LL Pegasi. The spiral pattern suggests a regular periodic origin for the nebula’s shape. The material forming the spiral is moving outwards a speed of about 50.000 km/hour and, by combining this speed with the distance between layers, astronomers calculate that the shells are each separated by about 800 years. The spiral is thought to arise because LL Pegasi is a binary system, with the star that is losing material and a companion star orbiting each other. (ESA/NASA, R. Sahai)

December 16, 2013
Day 16 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. The Antennae Galaxies. Known as NGC 4038 and NGC 4039, these two galaxies are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years in a clash so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions - some of which are partially obscured by dark patches of dust. The rate of star formation is so high that the Antennae Galaxies are said to be n a state of starburst, a period in which all of the gas within the galaxies is being used to form stars. (ESA/Hubble, NASA)

Day 16 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. The Antennae Galaxies. Known as NGC 4038 and NGC 4039, these two galaxies are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years in a clash so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions - some of which are partially obscured by dark patches of dust. The rate of star formation is so high that the Antennae Galaxies are said to be n a state of starburst, a period in which all of the gas within the galaxies is being used to form stars. (ESA/Hubble, NASA)

December 15, 2013
Day 15 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Abell 2261. The giant elliptical galaxy in the center of this image is the most massive and brightest member of the galaxy cluster Abell 2261. Spanning a little more than one million light-years, the galaxy is about 10 times the diameter of our Milky Way galaxy. The bloated galaxy is a member of an unusual class of galaxies with a diffuse core filled with a fog of starlight. Normally, astronomers would expect to see a concentrated peak of light around a central black hole. (NASA, ESA, M. Postman, STScI, T. Lauer, NOAO, and the CLASH team)

Day 15 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Abell 2261. The giant elliptical galaxy in the center of this image is the most massive and brightest member of the galaxy cluster Abell 2261. Spanning a little more than one million light-years, the galaxy is about 10 times the diameter of our Milky Way galaxy. The bloated galaxy is a member of an unusual class of galaxies with a diffuse core filled with a fog of starlight. Normally, astronomers would expect to see a concentrated peak of light around a central black hole. (NASA, ESA, M. Postman, STScI, T. Lauer, NOAO, and the CLASH team)

December 14, 2013
Day 14 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Light echoes of the star V838 Monocerotis. This image shows the dramatic illumination of surrounding dusty cloud structures, called a light echo, that built in brilliance for several years after the star suddenly brightened for several weeks in early 2002. The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a pulse of light three years before, somewhat similar to setting off a flashbulb in a darkened room. The dust surrounding V838 Mon may have been ejected from the star during a previous explosion, similar to the 2002 event. (NASA, ESA, and The Hubble Heritage Team, STScI/AURA)

Day 14 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Light echoes of the star V838 Monocerotis. This image shows the dramatic illumination of surrounding dusty cloud structures, called a light echo, that built in brilliance for several years after the star suddenly brightened for several weeks in early 2002. The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a pulse of light three years before, somewhat similar to setting off a flashbulb in a darkened room. The dust surrounding V838 Mon may have been ejected from the star during a previous explosion, similar to the 2002 event. (NASA, ESA, and The Hubble Heritage Team, STScI/AURA)

December 13, 2013
Day 13 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Comet ISON, before it broke apart as it rounded the Sun. Here, ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars. Discovered in 2012, the tiny ball of ice and rock (about 2 km in diameter), hurtled toward the Sun for a very close visit — passing approximately 1,165,000 km (724,000 mi) above the Sun’s surface at a relative speed of 1,359,900 kph (845,000 mph). The speed, gravitational forces, and extreme radiation were too much for ISON, which broke apart as it passed behind our star. (NASA, ESA, and the Hubble Heritage Team, STScI/AURA)

Day 13 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Comet ISON, before it broke apart as it rounded the Sun. Here, ISON floats against a seemingly infinite backdrop of numerous galaxies and a handful of foreground stars. Discovered in 2012, the tiny ball of ice and rock (about 2 km in diameter), hurtled toward the Sun for a very close visit — passing approximately 1,165,000 km (724,000 mi) above the Sun’s surface at a relative speed of 1,359,900 kph (845,000 mph). The speed, gravitational forces, and extreme radiation were too much for ISON, which broke apart as it passed behind our star. (NASA, ESA, and the Hubble Heritage Team, STScI/AURA)

December 12, 2013
Day 12 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Hubble caught Jupiter’s moon Ganymede just before it ducked behind the giant planet. Ganymede completes an orbit around Jupiter every seven days. Because Ganymede’s orbit is tilted nearly edge-on to Earth, it routinely can be seen passing in front of and disappearing behind its giant host, only to reemerge later. Composed of rock and ice, Ganymede is the largest moon in our solar system. It is even larger than the planet Mercury. But Ganymede looks like a dirty snowball next to Jupiter, the largest planet in our solar system. Jupiter is so big that only part of its Southern Hemisphere can be seen in this image. Hubble’s view is so sharp that astronomers can see features on Ganymede’s surface, most notably the white impact crater, Tros, and its system of rays, bright streaks of material blasted from the crater. Tros and its ray system are roughly the width of Arizona. (NASA, ESA, and E. Karkoschka, University of Arizona)

Day 12 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Hubble caught Jupiter’s moon Ganymede just before it ducked behind the giant planet. Ganymede completes an orbit around Jupiter every seven days. Because Ganymede’s orbit is tilted nearly edge-on to Earth, it routinely can be seen passing in front of and disappearing behind its giant host, only to reemerge later. Composed of rock and ice, Ganymede is the largest moon in our solar system. It is even larger than the planet Mercury. But Ganymede looks like a dirty snowball next to Jupiter, the largest planet in our solar system. Jupiter is so big that only part of its Southern Hemisphere can be seen in this image. Hubble’s view is so sharp that astronomers can see features on Ganymede’s surface, most notably the white impact crater, Tros, and its system of rays, bright streaks of material blasted from the crater. Tros and its ray system are roughly the width of Arizona. (NASA, ESA, and E. Karkoschka, University of Arizona)

December 11, 2013
Day 11 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Galaxy group Stephan’s Quintet is 290 million light-years away, in the constellation Pegasus. Four of these five galaxies are actually close enough to be locked in a vast intricate dance. Galaxy NGC 7320, the brighter galaxy at lower left, appears to be part of the group, but is in fact 250 million light years closer than the others. (NASA, ESA, and the Hubble SM4 ERO Team)

Day 11 of the 2013 Hubble Space Telescope Advent Calendar, one of 25 photos eventually. Galaxy group Stephan’s Quintet is 290 million light-years away, in the constellation Pegasus. Four of these five galaxies are actually close enough to be locked in a vast intricate dance. Galaxy NGC 7320, the brighter galaxy at lower left, appears to be part of the group, but is in fact 250 million light years closer than the others. (NASA, ESA, and the Hubble SM4 ERO Team)