A Colossal and Colorful Lagoon. To celebrate its 28th anniversary in space the Hubble Space Telescope made this spectacular image of glowing clouds of interstellar gas in the Lagoon Nebula, with observations taken between February 12 and 18, 2018. The whole nebula, about 4,000 light-years away, is an incredible 55 light-years across and 20 light-years tall. This image shows only a small part of this turbulent star-formation region, about four light-years across. #

A Distant Whirlpool. A face-on view of spiral galaxy NGC 3344, located about 20 million light-years from Earth. This galaxy is roughly half the size of our own Milky Way galaxy, and can be seen in the constellation of Leo Minor. This composite image is made up of observations made in wavelengths from the ultraviolet to the optical and the near-infrared in February of 2018. #

An Enormous Einstein Ring. At the center of this image full of various distant galaxies sits the glowing bulge of galaxy cluster SDSSJ0146-0929—a huge collection of hundreds of galaxies. The mass of this galaxy cluster is large enough to severely distort the spacetime around it, creating the odd, looping curves that almost encircle the cluster. These graceful arcs are examples of a cosmic phenomenon known as an Einstein ring, created as the light from a distant object passes by an extremely large mass. Here, the light from a background galaxy is diverted and distorted around the massive intervening cluster and forced to travel along many different light paths towards Earth, making it appear as though the galaxy is in several places at once. #

A Cosmic Shroud. This Hubble image shows a compact star-forming region called S106 in the constellation Cygnus, some 3,300 light years away from the Earth. A newly-formed star called S106 IR is hidden within swirls of dust at the center of the image, and is responsible for the surrounding gas cloud’s hourglass-like shape and the turbulence visible within. Light from glowing hydrogen is colored blue in this image. #

A Galactic Collision. NGC 5256, also called Markarian 266, is a pair of galaxies in its final messy stage of merging. Located 350 million light-years away from Earth, the pair of galaxies is swirling ever closer, their two glowing cores a mere 13,000 light-years apart, throwing off gas and dust structures in multiple directions. The crush of energy and matter is creating multiple star-forming regions, even though existing stars themselves rarely collide, because the distances are still so vast. Image made on December 14, 2017. #

A Protostellar Jet. A young star, IRAS 14568-6304, at center, is cloaked in a haze of golden gas and dust. It appears to be embedded in a swath of dark sky. This dark region is known as the Circinus molecular cloud, an object with a mass around 250,000 times that of the Sun, filled with gas, dust and young stars. The star IRAS 14568-6304 is driving a protostellar jet, which appears here as the "tail" below, made up of the leftover gas and dust that the star took from its parent cloud in order to form. #

The Antennae Galaxies. These two galaxies—once normal, spiral galaxies like the Milky Way—have spent the past few hundred million years violently clashing with one another. This interaction has ripped stars away from their host galaxies, forming 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. This gigantic cosmic dance is taking place 65 million light years away, in the Corvus constellation. #

The Boomerang Nebula. Located 5,000 light-years away, this reflecting cloud of dust and gas has two nearly symmetric lobes of matter that are being ejected from a central star. Each lobe of this protoplanetary nebula, also named the Bow Tie Nebula, is nearly one light-year in length. The gas in the lobes is expanding outward at extreme speeds, and has been observed as "the coldest spot in the known universe," with a temperature of -458 °F (-272 °C), only one degree above absolute zero. #

The Edge of a Galaxy. Spiral galaxy NGC 1032, located about a hundred million light years away in the constellation Cetus, is oriented edge-on to us, so the galaxy’s vast disc of gas, dust and stars appear as a dark stripe surrounded by a halo. A handful of other galaxies can be seen in the distant background. Many are oriented face-on or at tilted angles, showing off their glamorous spiral arms and bright cores. #

The Heart of the Crab Nebula. At the center of the Crab Nebula, 6,500 light-years away, lies a celestial "beating heart" that blasts out blistering pulses of radiation 30 times a second with clock-like precision. Astronomers discovered that it was the crushed core of an exploded star, called a neutron star, spinning incredibly fast. This Hubble image captures the region around the neutron star as it unleashes tremendous waves of energy that push on the expanding cloud of debris from the supernova explosion. #

A Hot Young Star Cluster. At the tender age of only about 500,000 years, star cluster Trumpler 14 has grown to be one of the largest gatherings of hot, massive and bright stars in the Milky Way, with some of the most luminous stars in our entire galaxy. This open cluster, still swirling with the clouds and clumps of gas and dust of star-making, lies about 8,000 light-years away, in the Carina Nebula. #

A Dusty Spiral. A face-on view of spiral galaxy NGC 4911, located deep within the Coma Cluster of galaxies, 320 million light-years away, lined with long clouds of dust and gas. These are seen in silhouette against glowing newborn star clusters and iridescent pink clouds of hydrogen, the existence of which indicates ongoing star formation. Hubble also captured the fainter outer spiral arms of NGC 4911, along with thousands of other galaxies of varying sizes in the background. #

A Colossal Shell of Light. Spirals of dust swirl across trillions of kilometers of interstellar space as an expanding halo of light around a distant star, named V838 Monocerotis illuminates the giant cloud. The glow comes from the red supergiant star at the middle of the image, which gave off a flashbulb-like pulse of light visible to us on Earth in 2002, This image shows the progress the light-pulse had made two years later, traveling away from the star in all directions, imaged by Hubble on February 8, 2004. V838 Monocerotis is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, at the outer edge of our Milky Way galaxy. #

Streamers from a Runaway Galaxy. Some 200 million light-years away, the spiral galaxy ESO 137-001 is caught by Hubble acting like a cosmic speed camera. This galaxy is moving toward the upper right of this image at a blazing speed of 4.5 million miles per hour. Recently, ESO 137-001 has been plowing through a region filled with hot intergalactic gas, and the collision is stripping away some of the galaxy's own gas, creating star-forming regions (blue streamers), and dust (smoky cloud at center of galaxy). #

A Stellar Sculpture. A massive star is illuminating this small star-forming region of the Orion Nebula, called M43, and carving the landscape of dust and gas. Astronomers call the area a miniature Orion Nebula because of its small size and the single star that is shaping it. M43 lies about 1,600 light-years away. #

A Massive Warping of Space. In the center of this image is the immense galaxy cluster Abell S1063, located 4 billion light-years away, surrounded by magnified images of galaxies much farther. The huge mass of the cluster distorts and magnifies the light from galaxies that lie far behind it due to an effect called gravitational lensing. The cluster contains approximately 100 million-million solar masses, and contains 51 confirmed galaxies with perhaps more than 400 more yet to be confirmed. #

A Galactic Hybrid. Galaxy UGC 12591 is classified as an S0/Sa galaxy, sitting somewhere between a lenticular and a spiral galaxy. It lies about 400 million light-years away from us in the Pisces–Perseus Supercluster, a long chain of galaxy clusters that stretches out for hundreds of light-years. This galaxy is incredibly massive, containing four times the mass of our Milky Way. #

Waves in the Lagoon Nebula. A close-up shot of the center of the Lagoon Nebula (Messier 8) shows the delicate structures formed when the powerful radiation of young stars interacts with the hydrogen cloud they formed from. Light from glowing hydrogen is colored red, from ionized nitrogen is green, and light through a yellow filter is colored blue. #

A Vast Expanding Bubble. The star that is forming NGC 7635, or the Bubble Nebula, is 45 times more massive than our sun. Gas on the star gets so hot that it escapes away into space as a "stellar wind" moving at over 4 million miles per hour. This outflow sweeps up the cold, interstellar gas in front of it, forming the outer edge of the bubble. As the surface of the bubble's shell expands outward, it slams into dense regions of cold gas on one side of the bubble. This asymmetry makes the star appear dramatically off-center in the bubble, with its location in the 10 o'clock position in this view. The Bubble Nebula is 7 light-years across and lies approximately 7,100 light-years away from Earth, in the constellation Cassiopeia. #

The Young and the Globular. This clutch of hundreds of thousands of stars is named NGC 362. It is a globular cluster, a grouping of stars that occurs on the outskirts of galaxies. NGC 362 is one of more than 150 known globular clusters in our Milky Way galaxy, and is one of the more unusual ones. Most globular clusters are much older than the majority of stars in their host galaxy, but NGC 362 bucks the trend, with an age lying between 10 and 11 billion years old. For reference, the age of the Milky Way is estimated to be more than 13 billion years. #

The Spiral Arms of M74. Located 25 million light-years away from us, spiral galaxy M74 is dotted with bright pink regions that are huge, relatively short-lived, clouds of hydrogen gas which glow from the strong radiation of hot, young stars embedded within them. M74 was first discovered in 1780, and is believed to be home to more than 100 billion stars. #

An Enormous Space Jet. Herbig-Haro 110 is a geyser of hot gas from a newborn star that splashes up against and ricochets off the dense core of a cloud of molecular hydrogen 1,300 light-years away from us. Herbig-Haro objects are made as twin jets of heated gas, ejected in opposite directions away from a forming star, stream through interstellar space. Astronomers suspect that these outflows are fueled by gas accreting onto a young star surrounded by a disk of dust and gas. The disk is the "fuel tank," the star is the gravitational engine, and the jets are the exhaust. #

A Pillar of Hydrogen. In a detail view of the Carina Nebula, an approximately one-light-year tall "pillar" of cold hydrogen towers above the wall of the molecular cloud. The 2.5-million-year-old star cluster called Trumpler 14 appears at the right side of the image. A small nugget of cold molecular hydrogen, called a Bok globule, is silhouetted against the star cluster at far right. #

Light in the Darkness. The little-known nebula IRAS 05437+2502 billows out among the bright stars and dark dust clouds that surround it. Unlike many of Hubble’s targets, this object has not been studied in detail and its exact nature is unclear. At first glance it appears to be a small, rather isolated, region of star formation and one might assume that the effects of fierce ultraviolet radiation from bright young stars probably were the cause of the eye-catching shapes of the gas. However, the bright boomerang-shaped feature may tell a more dramatic tale. The interaction of a high velocity young star and the cloud of gas and dust may have created this unusually sharp-edged bright arc. Such a reckless star would have been ejected a high speed from the distant young cluster where it was born. #

The Butterfly Nebula. What resemble dainty butterfly wings are actually roiling cauldrons of gas heated to more than 36,000 degrees Fahrenheit. The gas is tearing across space at more than 600,000 miles an hour. 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. NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The "butterfly" stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri. Merry Christmas everyone! I hope you've enjoyed this year's Hubble Advent Calendar. And, here's wishing for a peaceful and joyous New Year. -Alan #