HubbleSite

Forty years ago in 1981, the first space shuttle launched, the Voyager 2 space probe encountered Saturn, and in Baltimore, Maryland, the Space Telescope Science Institute (STScI) was founded. In that year, NASA selected a proposal by the Association of Universities for Research in Astronomy to establish STScI on the Johns Hopkins University Homewood campus. STScI began its life as the home of science operations for NASA’s Hubble Space Telescope. Since Hubble’s 1990 launch, the institute has processed and distributed Hubble’s data and shared Hubble’s images and discoveries with the world. As it celebrates its 40th anniversary, STScI is looking forward to the future and its added responsibilities for mission and science operations of NASA’s James Webb Space Telescope, as well as science operations for NASA’s Nancy Grace Roman Space Telescope. View the full article

Inhabitants of our Milky Way galaxy living several billion years from now will have a markedly different-looking sky overhead. Two brilliant objects, each as bright as the full Moon or brighter, will drown out the stars with their radiance. These giant blazing light bulbs are a pair of quasars, brought to life by the collision of our Milky Way with the neighboring Andromeda galaxy. Quasars are ignited by monster black holes voraciously feeding on infalling matter, unleashing a torrent of radiation. The Milky Way and Andromeda have such black holes at their hearts, which are now sleeping giants. That is, until the big bang-up. The duo will be as deadly then as it is dazzling. Blistering radiation from the quasar pair might sterilize the surfaces of planets, wiping out innumerable extraterrestrial civilizations. This tale of "death star" dueling quasars looming in the sky might seem like a scene out of a science fiction movie. But the real universe is stranger than fiction. This is actually a story that played out between two pairs of galaxies that existed long ago and far away. The four galaxies, each containing a central, bright quasar, are in the process of merging. As the two galaxies in each quasar pair move closer together, so do their quasars. Hubble caught the action, photographing two quasar pairs that existed 10 billion years ago, during the peak epoch of galaxy close encounters. The discovery offers a unique way to probe collisions among galaxies in the early universe that might otherwise have gone undetected. Ancient quasars are scattered all across the heavens, so finding these dynamic duos is fortuitous. Astronomers estimate only one in a thousand quasars are really double quasars. View the full article

The NHFP is one of the highlights of NASA's pursuit of excellence in astrophysics. The program enables outstanding postdoctoral scientists to pursue independent research in any area of NASA Astrophysics, using theory, observation, experimentation, or instrument development. Over 400 applicants vied for the fellowships. Each fellowship provides the awardee up to three years of support. View the full article

Stars aren't shy about announcing their births. As they are born from the collapse of giant clouds of hydrogen gas and begin to grow, they launch hurricane-like winds and spinning, lawn-sprinkler-style jets shooting off in opposite directions. This action carves out huge cavities in the giant gas clouds. Astronomers thought these stellar temper tantrums would eventually clear out the surrounding gas cloud, halting the star's growth. But in a comprehensive analysis of 304 fledgling stars in the Orion Complex, the nearest major star-forming region to Earth, researchers discovered that gas-clearing by a star's outflow may not be as important in determining its final mass as conventional theories suggest. Their study was based on previously collected data from NASA's Hubble and Spitzer space telescopes and the European Space Agency's Herschel Space Telescope. The study leaves astronomers still wondering why star formation is so inefficient. Only 30% of a hydrogen gas cloud's initial mass winds up as a newborn star. View the full article

The Wide Field Camera 3 (WFC3) instrument on NASA's Hubble Space Telescope was brought back online on Saturday, March 13th at approximately 7:00 p.m. EST. The instrument was shut down as part of the normal observatory safe mode activities that occurred on Sunday, March 7, in response to a software error on the main flight computer. After starting its recovery on Thursday, March 11, WFC3 suspended the process due to a slightly lower-than-normal voltage reading for a power supply, which triggered an internal instrument safeguard. View the full article

NASA is working to return the Hubble Space Telescope to science operations after resolving a problem with a safeguard aboard. Hubble entered safe mode on Sunday, March 7, shortly after 4 a.m. EST, following detection of a software error within the spacecraft’s main computer. The spacecraft has been moved out of safe mode into a pre-science state with the plan of returning to normal operations by Thursday night. View the full article

Orbiting a red dwarf star 41 light-years away is an Earth-sized, rocky exoplanet called GJ 1132 b. In some ways, GJ 1132 b has intriguing parallels to Earth, but in other ways it is very different. One of the differences is that its smoggy, hazy atmosphere contains a toxic mix of hydrogen, methane and hydrogen cyanide. Scientists using NASA's Hubble Space Telescope have found evidence this is not the planet's original atmosphere, and that the first one was blasted away by blistering radiation from GJ 1132 b's nearby parent star. The so-called "secondary atmosphere" is thought to be formed as molten lava beneath the planet's surface continually oozes up through volcanic fissures. Gases seeping through these cracks seem to be constantly replenishing the atmosphere, which would otherwise also be stripped away by the star. This is the first time a secondary atmosphere has been detected on a world outside our solar system. View the full article

Orbiting a red dwarf star 41 light-years away is an Earth-sized, rocky exoplanet called GJ 1132 b. In some ways, GJ 1132 b has intriguing parallels to Earth, but in other ways it is very different. One of the differences is that its smoggy, hazy atmosphere contains a toxic mix of hydrogen, methane and hydrogen cyanide. Scientists using NASA's Hubble Space Telescope have found evidence this is not the planet's original atmosphere, and that the first one was blasted away by blistering radiation from GJ 1132 b's nearby parent star. The so-called "secondary atmosphere" is thought to be formed as molten lava beneath the planet's surface continually oozes up through volcanic fissures. Gases seeping through these cracks seem to be constantly replenishing the atmosphere, which would otherwise also be stripped away by the star. This is the first time a secondary atmosphere has been detected on a world outside our solar system. View the full article

Stars come in an extraordinary range of sizes. One of the most colossal is VY Canis Majoris. If placed in the middle of our solar system it would engulf all the planets out to Saturn's orbit. This monster, appropriately called a red hypergiant, is as bright as 300,000 Suns. Yet it is so far away that, 200 years ago, it could be seen only as a faint star in the winter constellation of the Great Dog. Since then, it has faded and is no longer visible to the naked eye. Astronomers used Hubble to get a close-up look at the star and discovered the reason for the dimming. The star is expelling huge clouds of dust in the final stages of its life. Eventually, the bloated star may explode as a supernova, or may simply collapse and form a black hole. View the full article

Long road trips can be tedious and boring. That's why many road travelers break up their arduous journey by making rest stops along the way. Astronomers found that at least one roaming comet is doing the same thing. The wayward object made a temporary stop near giant Jupiter. The icy visitor has plenty of company: It has settled near the family of captured asteroids known as Trojans that are co-orbiting the Sun alongside Jupiter. This is the first time a comet-like object has been spotted near the Trojan asteroid population. Hubble Space Telescope observations reveal the vagabond is showing signs of transitioning from a frigid asteroid-like body to an active comet, sprouting a long tail, outgassing jets of material, and enshrouding itself in a coma of dust and gas. The interloper came from the frigid outskirts of our solar system, a comet nesting-ground called the Kuiper Belt. This nomad was likely snatched by Jupiter's powerful gravity after it had a brush with the giant planet. Jupiter's uninvited guest probably will not hang around the planet for very long. As the "bouncer" of the solar system, the monster planet's gravitational tug will eventually boot the comet back onto its road trip toward our Sun. View the full article

The idea that black holes come in different sizes may sound a little odd at first. After all, a black hole by definition is an object that has collapsed under gravity to an infinite density, making it smaller than the period at the end of this sentence. But the amount of mass a black hole can pack away varies widely from less than twice the mass of our Sun to over a billion times our Sun's mass. Midway between are intermediate-mass black holes (IMBHs) weighing roughly hundreds to tens of thousands of solar masses. So, black holes come small, medium, and large. However, the IMBHs have been elusive. They are predicted to hide out in the centers of globular star clusters, beehive-shaped swarms of as many as a million stars. Hubble researchers went hunting for an IMBH in the nearby globular cluster NGC 6397 and came up with a surprise. Because a black hole cannot be seen, they carefully studied the motion of stars inside the cluster, that would be gravitationally affected by the black hole's gravitational tug. The amplitudes and shapes of the stellar orbits led to the conclusion that there is not just one hefty black hole, but a swarm of smaller black holes – a mini-cluster in the core of the globular. Why are the black holes hanging out together? A gravitational pinball game takes place inside globular clusters where more massive objects sink to the center by exchanging momentum with smaller stars, that then migrate to the cluster's periphery. The central black holes may eventually merge, sending ripples across space as gravitational waves. View the full article

Sometime during the third century, a brilliant burst of light from the explosion of a massive star was visible from Earth. If the supernova blast had flashed over the northern hemisphere, it might have been considered an evil omen. At that time, Western Civilization was in upheaval. The Roman Empire was beginning to crumble. An emperor was assassinated, followed by political upheavals, civil wars, and barbarian attacks. But the violent supernova death could only be seen in the southern skies. The blast occurred in the nearby satellite galaxy, the Small Magellanic Cloud. No record exists of the titanic event. However, like the smoke and ash drifting across the sky after an aerial fireworks blast, the supernova left behind a cloud of debris that is still rapidly expanding today. This cloud provides forensic evidence for astronomical detectives to retrace the explosion. Astronomers sifting through Hubble observations of the supernova remnant, taken 10 years apart, have calculated the cloud's expansion rate. Analyzing the data was like rewinding a movie. The researchers traced the path of all the debris flung from the explosion back to the point in space where the doomed star blew apart. Their analysis reveals that the light from the exploded star reached Earth 1,700 years ago. View the full article

How dark is the sky, and what does that tell us about the number of galaxies in the visible universe? Astronomers can estimate the total number of galaxies by counting everything visible in a Hubble deep field and then multiplying them by the total area of the sky. But other galaxies are too faint and distant to directly detect. Yet while we can’t count them, their light suffuses space with a feeble glow. To measure that glow, astronomers have to escape the inner solar system and its light pollution, caused by sunlight reflecting off dust. A team of scientists has used observations by NASA’s New Horizons mission to Pluto and the Kuiper Belt to determine the brightness of this cosmic optical background. Their result sets an upper limit to the starlight emitted by faint, unresolved galaxies, showing that there is about twice as much optical light permeating space as can be accounted for by all known galaxies. View the full article

In 1995, the Hubble Space Telescope stared at a blank patch of the sky for 10 straight days. The resulting Deep Field image captured thousands of previously unseen, distant galaxies. Similar observations have followed since then, including the longest and deepest exposure, the Hubble Ultra Deep Field. Now, astronomers are looking ahead to the future, and the possibilities enabled by NASA’s upcoming Nancy Grace Roman Space Telescope. The Roman Space Telescope will be able to photograph an area of sky 100 times larger than Hubble with the same exquisite sharpness. As a result, a Roman Ultra Deep Field would collect millions of galaxies, including hundreds that date back to just a few hundred million years after the big bang. Such an observation would fuel new investigations into multiple science areas, from the structure and evolution of the universe to star formation over cosmic time. View the full article

When NASA's Voyager 2 spacecraft flew by Neptune in 1989 after a nearly 3-billion-mile odyssey, astronomers expected to get a close-up look at a blue-green planet that seemed as featureless as a marble. Instead, they were shocked and intrigued to see a dynamic and turbulent world of whirling storms, including a giant feature dubbed the Great Dark Spot, looming in Neptune's far southern hemisphere. The vortex was reminiscent of Jupiter's legendary Great Red Spot, a monstrous storm that has been raging for hundreds of years. Had this Great Dark Spot been brewing for the same amount of time? Or, was it a more ephemeral tempest? Scientists had to wait until 1994, when the Hubble Space Telescope and its crisp vision peered at distant Neptune. The mysterious spot had vanished! This game of planetary peek-a-boo continued when Hubble spotted another dark storm appearing in Neptune's northern hemisphere in 1995. Over the past three decades, Hubble has continued to observe the planet, watching several more dark spots come and go. Only Hubble can study these spots because it has the sharp vision to observe them in visible light. Hubble has shown that these storms live for a few years before vanishing or fading away. Researchers thought the current giant storm in the northern hemisphere was heading to destruction when it mysteriously halted its southern journey and began drifting northward. At the same time as the spot's stunning reversal, a new, slightly smaller dark feature appeared near its bigger cousin and later disappeared. These surprising events add to the mystery of this dynamic world. View the full article

Though every planet in our solar system has been visited by spacecraft over nearly the past 60 years, the outer frontier of the solar system, beyond Neptune, has been barely explored. There is circumstantial evidence that a planet five times Earth's mass – dubbed Planet Nine – may be lurking out there in the abyss. If real, it is creeping along a very wide orbit taking it 800 times farther from the Sun than Earth is. Though astronomers have yet to find this legendary world – if it exists at all – they have found another clue 336 light-years away. Astronomers analyzing Hubble images of the double star, HD 106906, have discovered a planet in a huge 15,000-year-long orbit that sweeps it as far from its stellar duo as Planet Nine would be from our Sun. This is observational evidence that similarly far-flung worlds may exist around other stars. Researchers hypothesize that the planet wound up there in a game of planetary pinball where the gravitational pull of a passing star modified the orbit's shape. Perhaps a passing star had a similar influence on our solar system 4.6 billion years ago. View the full article

Great things take time. This is true when it comes to many processes in the universe. For example, it takes millions of years for stars—the building blocks of the universe—to form. Then, many stars last for billions of years before they die and begin to eject shells of gas that glow against the vastness of space—what we call nebulas. It can be exceedingly rare to capture some of these processes in real time. Lucky for us, it seems as if the Stingray nebula, Hen 3-1357, was destined to stand out from the crowd since its beginnings. It was dubbed the youngest known planetary nebula in 1998 after Hubble caught a rare peek at the central star’s final stages of life. Now, twenty years after its first snapshot, the Stingray nebula is capturing the attention of astronomers again for a very different reason. Images from 2016 show a nebula that has drastically faded over the last two decades. Additionally, shells of gas that surrounded the central star have changed, no longer as crisp as they once were. Changes like this have never been captured at this clarity before. View the full article

Black holes are the universe's monsters: voracious eating machines that swallow anything that ventures near them. These compact behemoths pull stars and gas into a disk that swirls around them. The feeding generates a prodigious amount of energy, producing a powerful gusher of light from superheated infalling gas. These disks are so far away that it's nearly impossible to discern any detail about them. But by a quirk of alignment, astronomers may be getting a glimpse of the structure of the disk around the black hole in nearby galaxy IC 5063. The Hubble Space Telescope has observed a collection of narrow bright rays and dark shadows beaming out of the blazingly bright center of the active galaxy. One possible explanation for the effect is that the dusty disk of material surrounding the black hole is casting its shadow into space. Some light penetrates gaps in the dust ring, creating the bright rays that resemble the floodlights accompanying a Hollywood movie premier. These telltale beams offer clues to the distribution of material near the black hole that is causing the shadow play. What is fascinating is that we can see the same interplay of light and shadow in our sky at sunset, when the setting Sun casts streaks of bright rays and dark shadows through scattered clouds. View the full article

In our infinite universe, stars can go bump in the night. When this happens between a pair of burned-out, crushed stars called neutron stars, the resulting fireworks show, called a kilonova, is beyond comprehension. The energy unleashed by the collision briefly glows 100 million times brighter than our Sun. What's left from the smashup? Typically an even more crushed object called a black hole. But in this case Hubble found forensic clues to something even stranger happening after the head-on collision. The intense flood of gamma-rays signaling astronomers to this event has been seen before in other stellar smashups. But something unexpected popped up in Hubble's near-infrared vision. Though a gusher of radiation from the aftermath of the explosion—stretching from X-rays to radio waves—seemed typical, the outpouring of infrared radiation was not. It was 10 times brighter than predicted for kilonovae. Without Hubble, the gamma-ray burst would have appeared like many others, and scientists would not have known about the bizarre infrared component. The most plausible explanation is that the colliding neutron stars merged to form a more massive neutron star. It's like smashing two Volkswagen Beetles together and getting a limousine. This new beast sprouted a powerful magnetic field, making it a unique class of object called a magnetar. The magnetar deposited energy into the ejected material, causing it to glow even more brightly in infrared light than predicted. (If a magnetar flew within 100,000 miles of Earth, its intense magnetic field would erase the data on every credit card on our planet!) View the full article

Stars are not created equal. They span a broad range of sizes, ages, and temperatures from diminutive red, cool, low-mass stars to opulent blue, hot, massive stars. Our Sun is roughly midway between these populations. Because stars are the universe's LEGO blocks for building immense galaxies, astronomers are always seeking a much better understanding of their birth and death. Stars' behavior over their lifespan relates to everything from planets to the formation and evolution of galaxies. To better understand stars and their evolution, the Space Telescope Science Institute has launched an ambitious new initiative with the Hubble Space Telescope called ULLYSES (UV Legacy Library of Young Stars as Essential Standards). The comprehensive program will build a dataset that can be used to create a spectral library of stellar "templates" for capturing the diversity of stars. This is ensuring a legacy dataset for a wide range of astrophysical topics. Located above the obscuring atmosphere, Hubble's ultraviolet sensitivity makes it the only observatory currently capable of studying stars at those wavelengths of light. Young low-mass stars and massive monster stars radiate a lot of their energy in ultraviolet light. View the full article

In our infinite universe, if you can imagine something, you may eventually find it out there. And, that even goes for celestial objects that look like some creepy incarnation straight out of a Halloween tale. Hubble's holiday offering is a pair of colliding galaxies that resemble the cartoon Peanuts character Linus's imagining of the elusive Great Pumpkin. "Great" is an understatement in this case because the galaxy pair spans 100,000 light-years. The "pumpkin’s" glowing "eyes" are the bright, star-filled cores of each galaxy that contain supermassive black holes. An arm of newly forming stars embracing the pair gives the imaginary pumpkin a wry smirk. In about 6 billion years our Milky Way galaxy will collide with the neighboring Andromeda galaxy. When viewed from an extraterrestrial civilization far away, our collision may take on a spooky appearance too. That is, assuming they also have fertile imaginations for seeing ghostly entities among the stars. View the full article

Like most spiral galaxies, the Milky Way has a roughly spherical collection of stars at its center called the bulge. How the bulge formed has been a long-standing mystery, with many studies suggesting that it built up over time through multiple bursts of star formation. New research finds that the majority of stars in our galaxy’s central bulge formed in a single burst of star formation more than 10 billion years ago. To reach this conclusion, astronomers surveyed millions of stars across 200 square degrees of sky—an area equivalent to 1,000 full Moons. The resulting wealth of data is expected to fuel many more scientific inquiries. View the full article

Now you see it, now you don't. Though stars explode at the rate of one per second in the vast universe, it's rare to get a time-lapse movie of one fading into obscurity. This disappearing act, in a galaxy 70 million light-years away, was captured by the Hubble Space Telescope as part of a program to measure the universe's expansion rate. More than just providing celestial fireworks, supernovae can be used as milepost markers to measure distances to galaxies. This yardstick is needed to calculate how quickly galaxies appear to be flying apart from one another, which in turn provides an age estimate for the universe. The titanic explosion, which briefly outshined the entire host galaxy, originated from a white dwarf accreting material from its companion star. This pileup of gas eventually triggered a runaway thermonuclear explosion, making the dwarf nature's own atomic bomb. The energy briefly unleashed was equal to the radiance of 5 billion Suns. This time-lapse sequence of snapshots compresses nearly one year's worth of Hubble observations into a few seconds. View the full article

More massive than all the other planets combined, Jupiter truly is the king of our solar system. The swirling clouds, arranged in colorful, banded structures, change from year to year. The rich colors are produced by trace compounds in Jupiter’s predominantly hydrogen/helium atmosphere. Hurricane-force winds propel these clouds, and upwelling currents are ablaze with lightning bolts far more powerful than those seen on Earth. The Hubble Space Telescope serves as a “weather satellite” for monitoring Jupiter’s stormy weather. The iconic Great Red Spot, a storm big enough to swallow Earth, shows that it’s shrinking a little in the Hubble images, but it still dominates the entire southern atmosphere, plowing through the clouds like a cargo ship. Hubble astronomers patiently wait to get close-up snapshots as Earth make its nearest annual approach to Jupiter – an astronomical alignment called an opposition, when Jupiter is on the opposite side of the Earth from the Sun. “Closest approach” between the worlds is still on the order of nearly a half billion miles! View the full article

While studying the Coma galaxy cluster in 1933, astronomer Fritz Zwicky uncovered a problem. The mass of all the stars in the cluster added up to only a few percent of the heft needed to keep member galaxies from escaping the cluster's gravitational grip. He predicted that the "missing mass," now known as dark matter, was the glue that was holding the cluster together. Dark matter, as its name implies, is matter that cannot be seen. It does not emit, absorb, or reflect light, nor does it interact with any known particles. The presence of these elusive particles is only known through their gravitational pull on visible matter in space. This mysterious substance is the invisible scaffolding of our universe forming long filamentary structures—the cosmic web—along which galaxies form. Even more confounding is that dark matter makes up the vast bulk of the universe's overall mass content. The stuff that stars, planets, and humans are made of accounts for just a few percent of the universe's contents. Astronomers have been chasing this ghostly substance for decades but still don't have many answers. They have devised ingenious methods to infer dark matter's presence by tracing the signs of its gravitational effects. One technique involves measuring how dark matter's gravity in a massive galaxy cluster magnifies and warps light from a distant background galaxy. This phenomenon, called gravitational lensing, produces smeared images of remote galaxies and occasionally multiple copies of a single image. A recent study of 11 hefty galaxy clusters found that some small-scale clumps of dark matter are so concentrated that the lensing effects they produce are 10 times stronger than expected. These concentrations are associated with individual cluster galaxies. Researchers using the Hubble Space Telescope and the European Southern Observatory's Very Large Telescope in Chile discovered with unprecedented detail smaller-scale distorted images of remote galaxies nested like Matryoshka dolls within the larger-scale lens distortions in each cluster's core, where the most massive galaxies reside. This unexpected discovery means there is a discrepancy between these observations and theoretical models of how dark matter should be distributed in galaxy clusters. It could signal a gap in astronomers' current understanding of the nature of dark matter. View the full article