HubbleSite

On December 13th, NASA’s Hubble Space Telescope photographed comet 46P/Wirtanen, a periodic comet that orbits the Sun once every 5.4 years. These observations were taken days before the comet’s closest approach to Earth on December 16th, when it passed just over 7 million miles from our planet. Astronomers took advantage of this unusually close approach to study the comet’s inner cloud of gas and dust, or coma, in detail. Their goal was to study how gases are released from ices in the nucleus, what the comet’s ices are composed of, and how gas in the coma is chemically altered by sunlight and solar radiation. In this image, the comet’s nucleus is hidden in the center of a fuzzy glow from the comet’s coma. View the full article

Utilizing the powerful Hubble Frontier Fields observations of galaxy clusters, a study demonstrates that intracluster light — the light of stars orphaned in galaxy cluster mergers — aligns with dark matter, tracing its distribution more accurately than other methods. With broader use, astronomers think the technique could be a first step in exploring the nature of the unobservable, elusive dark matter that makes up the majority of the universe. View the full article

In nabbing exoplanets that are precariously close to their stars, astronomers have discovered a shortage of one type of alien world. It's a predicted class of Neptune-sized world that orbits just a few million miles from its star, much closer than the 93-million-mile distance between Earth and the Sun. Dubbed "hot Neptunes," these planets would have atmospheres that are heated to more than 1,700 degrees Fahrenheit (hot enough to melt silver). However, the mysterious hot-Neptune deficiency suggests that these planets are rare, or, they were plentiful at one time, but have since disappeared. In fact, most of the known Neptune-sized exoplanets are merely "warm," because they orbit farther away from their star than those in the region where astronomers would expect to find hot Neptunes. To date, astronomers have discovered two warm Neptunes that are leaking their atmospheres into space. The most recent finding, a planet cataloged as GJ 3470b, is losing its atmosphere at a rate 100 times faster than that of the previously discovered evaporating warm Neptune, GJ 436b. These discoveries reinforce the idea that the hotter version of these distant worlds may be a class of transitory planet whose ultimate fate is to shrink down to the most common type of known exoplanet, mini-Neptunes — planets with heavy, hydrogen-dominated atmospheres that are larger than Earth but smaller than Neptune. Eventually, these planets may downsize even further to become super-Earths, more massive, rocky versions of Earth. If GJ 3470b continues to rapidly lose mass, in a few billion years, perhaps it, too, will dwindle to a mini-Neptune. View the full article

The worldwide astronomical community mourns the loss of Riccardo Giacconi, the first permanent director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. View the full article

Over the past 28 years Hubble has photographed innumerable galaxies throughout the universe, near and far. But one especially photogenic galaxy located 55 million light-years away holds a special place in Hubble history. As NASA made plans to correct Hubble's blurry vision in 1993 (due to a manufacturing flaw in its primary mirror) they selected several astronomical objects that Hubble should be aimed at to demonstrate the planned optical fix. The magnificent grand spiral galaxy M100 seemed an ideal target that would just fit inside Hubble's field-of-view. This required that a comparison photo be taken while Hubble was still bleary-eyed. The Wide Field/Planetary Camera 1 was selected for the task. And, the picture had to be taken before astronauts swapped-out the camera with the vision-corrected Wide Field/Planetary Camera 2, in December 1993. Following the servicing mission Hubble re-photographed the galaxy again, and it snapped into crystal clear focus. The public celebrated with Hubble's triumphant return to the clear vision that had been promised. And, jaw-dropping pictures of the vast universe that followed have not disappointed space enthusiasts. Because of the astronaut servicing missions, Hubble's capabilities have only gotten better. To commemorate the 25th anniversary of the first servicing mission, this 2-panel photo compares the blurry, pre-servicing 1993 image to a 2009 image taken with Hubble's newer, Wide Field Camera 3 instrument, installed during the last astronaut servicing mission to the space telescope. View the full article

Globular star clusters are favorite targets for amateur sky watchers. To the naked eye they appear as fuzzy-looking stars. Through a small telescope they resolve into glittering snowball-shaped islands of innumerable stars crowded together. About 150 globular star clusters orbit our Milky Way, like bees buzzing around a hive. They are the earliest homesteaders of our galaxy, containing the universe's oldest known stars. Hubble is so powerful it can see globular star clusters 300 million light-years away. And, a lot of them. Peering into the heart of the giant Coma cluster of galaxies Hubble captured a whopping 22,426 globular star clusters. The survey found the globular clusters scattered in space among the 1,000 galaxies inside the Coma cluster. They have been orphaned from their home galaxy due to galaxy near-collisions inside the traffic-jammed galaxy cluster. Because they are so numerous in the Coma cluster, they are excellent tracers of the entire gravitational field that keeps the galaxies from flinging off into space. The gravity is a tracer of the distribution of dark matter. View the full article

In the early morning of October 27, 2018, the Hubble Space Telescope targeted a field of galaxies not far from the Great Square in the constellation Pegasus. Contained in the field were star-forming galaxies up to 11 billion light-years away. With the target in its sights, Hubble's Wide Field Camera 3 recorded an image. It was the first picture captured by the telescope since it closed its eyes on the universe three weeks earlier, and it was the result of an entire team of engineers and experts working tirelessly to get the telescope exploring the cosmos once again. View the full article

November 16 marks the premiere of a unique film and musical experience inspired by the Hubble Space Telescope’s famous Deep Field image. It represents a first-of-its-kind collaboration between Grammy award-winning American composer and conductor Eric Whitacre, producers Music Productions, multi award-winning artists 59 Productions, and the Space Telescope Science Institute (STScI). Deep Field: The Impossible Magnitude of our Universe features a variety of Hubble’s stunning imagery and includes 11 computer-generated visualizations of far-flung galaxies, nebulas, and star clusters developed by STScI. The film is available on YouTube and will be shared with the world through screenings and live performances around the globe. View the full article

The explosive end to a massive star's life is one of the most powerful blasts in the universe. The material expelled by the violent stellar death enriches our galaxy with heavier elements, the building blocks of new stars and even planetary systems. Astronomers have diligently searched for the doomed progenitor stars in pre-explosion images. Studying these stars could help them in their quest to better understand stellar evolution. Their quest has turned up a few pre-supernova stars. But the doomed stars for one class of supernova have eluded discovery: the hefty stars that explode as Type Ic supernovas. These stars, weighing more than 30 times our Sun's mass, lose their hydrogen and helium layers before their cataclysmic death. Researchers thought they should be easy to find because they are big and bright. However, they have come up empty. Finally, in 2017, astronomers got lucky. A nearby star ended its life as a Type Ic supernova. Two teams of researchers pored through the archive of Hubble images to uncover the putative precursor star in pre-explosion photos taken in 2007. The supernova, catalogued as SN 2017ein, appeared near the center of the nearby spiral galaxy NGC 3938, located roughly 65 million light-years away. An analysis of the candidate star's colors shows that it is blue and extremely hot. Based on that assessment, both teams suggest two possibilities for the source's identity. The progenitor could be a single star between 45 and 55 times more massive than our Sun. Another idea is that it could have been a binary-star system in which one of the stars weighs between 60 and 80 times our Sun's mass and the other roughly 48 solar masses. In this latter scenario, the stars are orbiting closely and interact with each other. The more massive star is stripped of its hydrogen and helium layers by the close companion, and eventually explodes as a supernova. View the full article

Some of the Hubble Space Telescope's most stunning images reveal galaxies in distress. Many of them are in the throes of a gravitational encounter with another galaxy. The photos show perfect pinwheel patterns stretched and pulled into irregular shapes. Streamers of gas and dust flow from galaxies into space. And in this chaos, batches of young, blue stars glow like tree lights, fueled by the dust and gas kicked up by the galactic encounter. For some galaxies, the powerful meeting with a passing galaxy will eventually end in mergers. But hidden from view deep inside the dusty cores of these merging galaxies is the slow dance of their supermassive black holes toward an eventual union. Visible light cannot penetrate these shrouded central regions. X-ray data, however, have detected the black-hole courtship. And now astronomers analyzing near-infrared images from the sharp-eyed Hubble Space Telescope and the W. M. Keck Observatory in Hawaii are offering the best view yet of close pairs of black holes as they move slowly toward each other. The study is the largest survey of the cores of nearby galaxies in near-infrared light. The Hubble observations represent over 20 years' worth of snapshots from its vast archive. The survey targeted galaxies residing an average distance of 330 million light-years from Earth. The census helps astronomers confirm computer simulations showing that black holes grow faster during the last 10 million to 20 million years of the galactic merger. The Hubble and Keck Observatory images captured close-up views of this final stage, when the bulked-up black holes are only about 3,000 light-years apart — a near-embrace in cosmic terms. The study shows that galaxy encounters are important for astronomers' understanding of how black holes became so monstrously big. These monster black holes also unleash powerful energy in the form of gravitational waves, the kind of ripples in space-time that were just recently detected by ground-breaking experiments. The images also provide a close-up preview of a phenomenon that must have been more common in the early universe, when galaxy mergers were more frequent. View the full article

The Kepler spacecraft launched in 2009 with the goal of finding exoplanets orbiting distant stars. In the years since, astronomers have used Kepler observations to discover 2,818 exoplanets as well as another 2,679 exoplanet candidates which need further confirmation. On October 30, 2018 NASA announced that Kepler had run out of fuel and would be decommissioned. While spacecraft operations have ceased, its data will continue to be publicly available through the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. These data will enable new scientific discoveries for years to come. View the full article

Like a fly that wanders into a flashlight’s beam, a young star’s planet-forming disk is casting a giant shadow, nicknamed the “Bat Shadow.” Hubble’s near-infrared vision captured the shadow of the disk of this fledgling star, which resides nearly 1,300 light-years away in a stellar nursery called the Serpens Nebula. In this Hubble image, the shadow spans approximately 200 times the length of our solar system. It is visible in the upper right portion of the picture. The young star and its disk likely resemble what the solar system looked like when it was only 1 or 2 million years old. View the full article

On Saturday, Oct. 27 at 2:10 a.m. EDT, Hubble completed its first science operations since entering safe mode on Oct. 5. The return to conducting science comes after successfully recovering a backup gyroscope, or gyro, that had replaced a failed gyro three weeks earlier. Hubble is now back in its normal science operations mode with three fully functional gyros. Originally required to last 15 years, Hubble has now been at the forefront of scientific discovery for more than 28 years. The team expects the telescope will continue to yield amazing discoveries well into the next decade. View the full article

The brightest stars embedded in nebulae throughout our galaxy pour out a torrent of radiation that eats into vast clouds of hydrogen gas – the raw material for building new stars. This etching process sculpts a fantasy landscape where human imagination can see all kinds of shapes and figures. A nebula in the constellation of Cassiopeia has flowing veils of gas and dust that have earned it the nickname "Ghost Nebula." The nebula is being blasted by a torrent of radiation from a nearby, blue-giant star called Gamma Cassiopeiae, which can be easily seen with the unaided eye at the center of the distinctive "W" asterism that forms the constellation. This Hubble Space Telescope view zooms in on the creepy-looking top of the nebula, material is swept away from it, forming a fantail shape. IC 63 is located 550 light-years away. View the full article

The term "HAZMAT" connotes danger. In this case, it's on a cosmic scale, where violent flares of seething gas from small, young stars may make entire planets uninhabitable. NASA's Hubble Space Telescope is observing such stars through a large program called HAZMAT — HAbitable Zones and M dwarf Activity across Time. This is an ultraviolet survey of red dwarfs — referred to as "M dwarfs" in astronomical circles — at three different ages: young, intermediate, and old. Approximately three-quarters of the stars in our galaxy are red dwarfs. Most of the galaxy's "habitable-zone" planets orbit these small stars. But young red dwarfs are active stars, producing ultraviolet flares that blast out million-degree plasma with an intensity that could influence atmospheric chemistry and possibly strip off the atmospheres of these fledgling planets. The HAZMAT team found that flares from the youngest red dwarfs they surveyed — around 40 million years old — are 100 to 1,000 times more energetic than when the stars are older. This is the age when terrestrial planets are forming around their stars. Scientists also detected one of the most intense stellar flares ever observed in ultraviolet light. Dubbed the "Hazflare," this event was more energetic than the most powerful flare from our Sun ever recorded. View the full article

On Friday, October 5, 2018, at approximately 6:00 p.m. EDT, NASA’s Hubble Space Telescope entered safe mode. NASA is working to resume science operations. Hubble’s instruments still are fully operational and are expected to produce excellent science for years to come. View the full article

Our solar system has eight major planets, and nearly 200 moons. Though astronomers have to date found nearly 4,000 planets orbiting other stars, no moons have yet been found. That hasn't been for any lack of looking, it’s just that moons are smaller than planets and therefore harder to detect. The Hubble and Kepler space telescopes found evidence for what could be a giant moon accompanying a gas-giant planet that orbits the star Kepler-1625, located 8,000 light-years away in the constellation Cygnus. The moon may be as big as Neptune and it orbits a planet several times more massive than Jupiter. If our solar system is a typical example, moons may outnumber planets in our galaxy by at least an order of magnitude or more. This promises a whole new frontier for characterizing the nature of moons and their potential for hosting life as we know it. The exomoon at Kepler-1625b is too far away to be directly photographed. Its presence is inferred when it passes in front of the star, momentarily dimming its light. Such an event is called a transit. However, the "footprint" of the moon's transit signal is weaker than for the host planet. The researchers caution that the moon’s presence will need to be conclusively proven by follow-up Hubble observations. View the full article

Imagine crushing more than 50,000 aircraft carriers into the size of a baseball. This describes neutron stars. They are among the strangest objects in the universe. Neutron stars are a case of extreme physics produced by the unforgiving force of gravity. The entire core of an exploded star has been squeezed into a solid ball of neutrons with the density of an atom’s nucleus. Neutron stars spin as fast as a blender on puree. Some spit out death-star beams of intense radiation — like interstellar lighthouses. These are called pulsars. These beams are normally seen in X-rays, gamma-rays, and radio waves. But astronomers used Hubble's near-infrared (IR) vision to look at a nearby neutron star cataloged RX J0806.4-4123. They were surprised to see a gush of IR light coming from a region around the neutron star. That infrared light might come from a circumstellar disk 18 billion miles across. Another idea is that a wind of subatomic particles from the pulsar’s magnetic field is slamming into interstellar gas. Hubble's IR vision opens a new window into understanding how these "infernal machines" work. View the full article

The universe is a big place. The Hubble Space Telescope's views burrow deep into space and time, but cover an area a fraction the angular size of the full Moon. The challenge is that these "core samples" of the sky may not fully represent the universe at large. This dilemma for cosmologists is called cosmic variance. By expanding the survey area, such uncertainties in the structure of the universe can be reduced. A new Hubble observing campaign, called Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO), will boldly expand the space telescope's view into regions that are adjacent to huge galaxy clusters previously photographed by NASA's Spitzer and Hubble space telescopes under a program called Frontier Fields. The six massive clusters were used as "natural telescopes," to look for amplified images of galaxies and supernovas that are so distant and faint that they could not be photographed by Hubble without the boost of light caused by a phenomenon called gravitational lensing. The clusters' large masses, mainly composed of dark matter, magnify and distort the light coming from distant background galaxies that otherwise could not be detected. The BUFFALO program is designed to identify galaxies in their earliest stages of formation, less than 800 million years after the big bang. View the full article

Astronomy has always been a preeminently visual science, going back thousands of years to the early sky watchers. Hubble’s jaw-dropping views of far-flung planets, nebulas, and galaxies have redefined the universe for whole new generations. Nearly all of Hubble’s dazzling images have been prepared with the skills of Zoltan Levay, in the STScI Office of Public Outreach. Levay is retiring now to pursue his hobby of photography on a more earth-bound plane. He leaves behind a 25-year-long legacy of several thousand colorful space pictures that communicate the mystery and wonder of the universe. Levay blended traditional photographic skills with science data to yield aesthetically pleasing pictures that are both enticing and informative. He carefully balanced the objective and subjective elements of imagery to capture the essence of intrinsically wondrous celestial landscapes. View the full article

Astronomers have just assembled one of the most comprehensive portraits yet of the universe’s evolutionary history, based on a broad spectrum of observations by the Hubble Space Telescope and other space and ground-based telescopes. In particular, Hubble’s ultraviolet vision opens a new window on the evolving universe, tracking the birth of stars over the last 11 billion years back to the cosmos’ busiest star-forming period, about 3 billion years after the big bang. This photo encompasses a sea of approximately 15,000 galaxies — 12,000 of which are star-forming — widely distributed in time and space. View the full article

It takes more than a massive outburst to destroy the mammoth star Eta Carinae, one of the brightest known stars in the Milky Way galaxy. About 170 years ago, Eta Carinae erupted, unleashing almost as much energy as a standard supernova explosion. Yet that powerful blast wasn’t enough to obliterate the star, and astronomers have been searching for clues to explain the outburst ever since. Although they cannot travel back to the mid-1800s to witness the actual eruption, they can watch a rebroadcast of part of the event — courtesy of some wayward light from the explosion. Rather than heading straight toward Earth, some of the light from the outburst rebounded or “echoed” off of interstellar dust, and is just now arriving at Earth. This effect is called a light echo. The surprise is that new measurements of the 19th-century eruption, made by ground-based telescopes, reveal material expanding with record-breaking speeds of up to 20 times faster than astronomers expected. The observed velocities are more like the fastest material ejected by the blast wave in a supernova explosion, rather than the relatively slow and gentle winds expected from massive stars before they die. Based on the new data, researchers suggest that the 1840s eruption may have been triggered by a prolonged stellar brawl among three rowdy sibling stars, which destroyed one star and left the other two in a binary system. This tussle may have culminated with a violent explosion when Eta Carinae devoured one of its two companions, rocketing more than 10 times the mass of our Sun into space. The ejected mass created gigantic bipolar lobes resembling the dumbbell shape seen in present-day images. View the full article

As Saturn and Mars ventured close to Earth, Hubble captured their portraits in June and July 2018, respectively. The telescope photographed the planets near opposition, when the Sun, Earth and an outer planet are lined up, with Earth sitting in between the Sun and the outer planet. Around the time of opposition, a planet is at its closest distance to Earth in its orbit. Hubble viewed Saturn on June 6, when the ringed world was approximately 1.36 billion miles from Earth, as it approached a June 27 opposition. Mars was captured on July 18, at just 36.9 million miles from Earth, near its July 27 opposition. Hubble saw the planets during summertime in Saturn’s northern hemisphere and springtime in Mars’ southern hemisphere. The increase in sunlight in Saturn’s northern hemisphere heated the atmosphere and triggered a large storm that is now disintegrating in Saturn’s northern polar region. On Mars, a spring dust storm erupted in the southern hemisphere and ballooned into a global event enshrouding the entire planet. View the full article

Using the powerful Hubble and Gaia space telescopes, astronomers just took a big step toward finding the answer to the Hubble constant, one of the most important and long-sought numbers in all of cosmology. This number measures the rate at which the universe is expanding since the big bang, 13.8 billion years ago. The constant is named for astronomer Edwin Hubble, who nearly a century ago discovered that the universe was uniformly expanding in all directions. Now, researchers have calculated this number with unprecedented accuracy. Intriguingly, the new results further intensify the discrepancy between measurements for the expansion rate of the nearby universe, and those of the distant, primeval universe — before stars and galaxies even existed. Because the universe is expanding uniformly, these measurements should be the same. The so-called “tension” implies that there could be new physics underlying the foundations of the universe. View the full article

Using observations from NASA’s Hubble Space Telescope and ground-based observatories, an international team of scientists have confirmed `Oumuamua (oh-MOO-ah-MOO-ah), the first known interstellar object to travel through our solar system, got an unexpected boost in speed and shift in trajectory as it passed through the inner solar system last year. View the full article