NASA's Hubble Reveals Possible New Moons Around Pluto
NASA's Hubble Space Telescope has spotted two possible new moons orbiting Pluto, the ninth planet in our solar system. If confirmed, the candidate moons could provide new insight into the nature and evolution of the Pluto system and the early Kuiper Belt. The Kuiper Belt is a vast region of icy, rocky bodies beyond Neptune's orbit.
These Hubble Space Telescope images reveal Pluto, its large moon Charon, and the planet's two new candidate satellites. Between May 15 and May 18, 2005, Charon, and the putative moons all appear to rotate counterclockwise around Pluto.
Mars Kicks Up the Dust as it Makes Closest Approach to Earth
NASA's Hubble Space Telescope snapped this picture of Mars on October 28, within a day of its closest approach to Earth on the night of October 29. The large regional dust storm appears as the brighter, redder cloudy region in the middle of the planet's disk. This storm, which measures 930 miles (1500 km) has been churning in the planet's equatorial regions for several weeks now, and it is likely responsible for the reddish, dusty haze and other dust clouds seen across this hemisphere of the planet. Hubble's Advanced Camera for Surveys High Resolution Imager took this image when the red planet was 43 million miles (69 million km) from Earth. Mars won't be this close again to Earth until 2018. Mars is now in its warmest months, closest to the Sun in its orbit, resulting in a smaller than normal south polar ice cap which has largely sublimated with the approaching summer.
NASA's Hubble Discovers New Rings and Moons Around Uranus
Even though the Voyager 2 spacecraft paid a close-up visit to Uranus in 1986, the distant planet continues revealing surprises to the eye of NASA's Hubble Space Telescope. Hubble's high sensitivity and sharp view has uncovered a pair of giant rings girdling the planet. The largest is twice the diameter of the planet's previously known ring system, first discovered in the late 1970s. Hubble also spied two small satellites, named Mab and Cupid. One of the satellites shares an orbit with the outermost of the new rings. The satellite is probably the source of fresh dust that keeps replenishing the ring with new material knocked off the satellite from meteoroid impacts. Without such replenishment, the dust in the ring would slowly spiral in toward Uranus. Collectively, these new discoveries mean that Uranus has a youthful and dynamic system of rings and moons. Because of the extreme tilt of Uranus's axis, the ring system appears nearly perpendicular relative to rings around other gas giant planets like Saturn. Also, unlike Saturn, the rings are very dark and dim because they are mostly dust rather than ice.
By stretching the capabilities of NASA's Hubble Space Telescope to the limit, astronomers have photographed the close companion of Polaris for the first time. This sequence of images shows that the North Star, Polaris is really a triple star system. These findings were presented today in a press conference at the 207th meeting of the American Astronomical Society in Washington, D.C.
Astronomers Map a Hypergiant Star's Massive Outbursts
Using NASA's Hubble Space Telescope and the W.M. Keck Observatory, Kameula, Hawaii, astronomers have learned that the gaseous outflow from one of the brightest super-sized stars in the sky is more complex than originally thought.
The outbursts are from VY Canis Majoris, a red supergiant star that is also classified as a hypergiant because of its very high luminosity. The eruptions have formed loops, arcs, and knots of material moving at various speeds and in many different directions. The star has had many outbursts over the past 1,000 years as it nears the end of its life.
Astronomers using NASA's Hubble Space Telescope have discovered a ghostly ring of dark matter that formed long ago during a titanic collision between two massive galaxy clusters. The ring's discovery is among the strongest evidence yet that dark matter exists. Astronomers have long suspected the existence of the invisible substance as the source of additional gravity that holds together galaxy clusters. Such clusters would fly apart if they relied only on the gravity from their visible stars. Although astronomers don't know what dark matter is made of, they hypothesize that it is a type of elementary particle that pervades the universe.
This Hubble composite image shows the ring of dark matter in the galaxy cluster Cl 0024+17. The ring-like structure is evident in the blue map of the cluster's dark matter distribution. The map was derived from Hubble observations of how the gravity of the cluster Cl 0024+17 distorts the light of more distant galaxies, an optical illusion called gravitational lensing. Although astronomers cannot see dark matter, they can infer its existence by mapping the distorted shapes of the background galaxies. The map is superimposed on a Hubble Advanced Camera for Surveys image of the cluster taken in November 2004.
Stellar Motions in Outer Halo Shed New Light on Milky Way Evolution
Peering deep into the vast stellar halo that envelops our Milky Way galaxy, astronomers using NASA's Hubble Space Telescope have uncovered tantalizing evidence for the possible existence of a shell of stars that are a relic of cannibalism by our Milky Way.
Hubble was used to precisely measure, for the first time ever, the sideways motions of a small sample of stars located far from the Milky Way galaxy's center. Their unusual lateral motion is circumstantial evidence that the stars may be the remnants of a shredded galaxy that was gravitationally ripped apart by the Milky Way billions of years ago. These stars support the idea that the Milky Way grew, in part, through the accretion of smaller galaxies.
Gravitational Lens Creates Cartoon of Space Invader
The universe is eerie enough without giving us an apparition of a 1980s video game alien attacker. This oddball-looking object is really a mirage created by the gravitational field of a foreground cluster of galaxies warping space and distorting the background images of more distant galaxies.
This effect, called gravitational lensing, can make multiple mirror image copies of the light coming from a far-flung galaxy. It is a powerful tool for seeing remote galaxies that otherwise would not be observable by Hubble because they are too dim and far away. In this Hubble photo a background spiral galaxy is warped into an image that resembles a cartoon of a simulated space invader. The foreground massive cluster, called Abell 68, lies 2 billion light-years away. The brightened and stretched lensed images come from galaxies far behind it.
Hubble Finds Birth Certificate of Oldest Known Star
You can't be older than your parents. But there is a nearby star that at first glance looks like it is older than the universe! Hubble Space Telescope astronomers are coming to grips with this paradox by improving the precision of the observations used to estimate the age of this "Methuselah star."
Around the year 2000, estimates for the star's age were about 16 billion years. But the universe is about 13.8 billion years old, based on a meticulous calibration of the expansion of space and analysis of the microwave afterglow from the big bang. Hubble data and improved theoretical calculations were used to recalculate the star's age and lower the estimate to 14.5 billion years, within a measurement uncertainty of plus or minus 800 million years. This places the star within a comfortable range to be younger than the universe. Astronomers have to collect a lot of information to deduce a star's age because it doesn't come with a birth certificate. They have to take into account where the star is in its life history, the detailed chemistry of the star, and its intrinsic brightness. Hubble's contribution was to reduce the uncertainty on the star's true distance. With that improved accuracy, the intrinsic brightness of the star is better known. The ancient star is still spry for its age. It is speeding past us at 800,000 miles per hour. Its orbit can be traced back to the halo of our galaxy, which is a "retirement home" for stars that were born long before the Milky Way was even fully assembled.
Hubble Breaks Record in Search for Farthest Supernova
A long time ago, in a galaxy far, far away, a star detonated with enough energy to briefly shine with an intrinsic brightness of one billion of our suns. The beacon of radiation arrived at Earth 10 billion years later and was captured in a Hubble Space Telescope deep survey of the universe. It is the farthest, and earliest, supernova of its type detected to date. More than simply an example of the ancient fireworks in the young and effervescent universe, the supernova belongs to a special class of stellar detonations that are so reliably bright, they can be used as intergalactic milepost markers.
Supernovae like this one provided the first observational evidence that the universe is expanding at an ever-faster rate. Our understanding of the accelerating universe, however, is only as solid as the reliability of supernovae as solid yardsticks for measuring cosmic distances. This record-breaker is so ancient it can be used to test competing theories about how such supernovae exploded in the universe's early days and compare them with nearby supernovae seen today. Its discovery is part of an ongoing program, where different teams of astronomers are using Hubble to push ever farther back into the early epoch of star formation.
Unlike other celestial objects there is no question how the Horsehead Nebula got its name. This iconic silhouette of a horse's head and neck pokes up mysteriously from what look like whitecaps of interstellar foam. The nebula has graced astronomy books ever since its discovery over a century ago. But Hubble's infrared vision shows the horse in a new light. The nebula, shadowy in optical light, appears transparent and ethereal when seen at infrared wavelengths. This pillar of tenuous hydrogen gas laced with dust is resisting being eroded away by the radiation from a nearby star. The nebula is a small part of a vast star-forming complex in the constellation Orion. The Horsehead will disintegrate in about 5 million years.
As part of Hubble's 23rd anniversary Horsehead Nebula release, amateur astronomers around the world were invited to send in their Horsehead Nebula photos. Visit the Hubble Heritage Horsehead Image Release to view the contributions via Flickr and Tumblr and to send us your own image.
Comet ISON is potentially the "comet of the century" because around the time the comet makes its closest approach to the Sun, on November 28, it may briefly become brighter than the full Moon. Right now the comet is far below naked-eye visibility, and so Hubble was used to snap the view of the approaching comet, which is presently hurtling toward the Sun at approximately 47,000 miles per hour. When the Hubble picture was taken on April 10, the comet was slightly closer than Jupiter's orbit at a distance of 386 million miles from the Sun. Even at that great distance the Sun is warming the comet enough to trigger outgassing from its frozen gases locked up in the solid nucleus. Hubble photographed a jet blasting dust particles off the sunward-facing side of the comet's nucleus. Preliminary measurements from the Hubble images suggest that the nucleus of ISON is no larger than three or four miles across. The comet was discovered in September 2012 by the Russian-led International Scientific Optical Network (ISON) using a 16-inch telescope.
Hubble Finds Dead Stars 'Polluted' with Planet Debris
Deep inside the Hyades star cluster, a pair of burned-out stars are yielding clues to the presence of rocky planets that may have whirled around them. Asteroid debris is 'raining' into the hot atmospheres of these white dwarfs. Asteroids should consist of the same material that form terrestrial planets, and seeing evidence of asteroids points to the possibility of Earth-sized planets in the same system.
Hubble's Cosmic Origins Spectrograph observed silicon and only low levels of carbon in the white dwarfs' atmospheres. Silicon is a major ingredient of the rocky material that constitutes Earth and other solid planets in our solar system. Astronomers used sophisticated computer models of white dwarf atmospheres to determine the abundances of various elements that can be traced to planets in the Hubble spectrograph data.
NASA's Hubble Space Telescope Reveals the Ring Nebula's True Shape
The distinctive shape of the Ring Nebula, the glowing shroud around a dying Sun-like star, makes it a popular celestial object that appears in many astronomy books. New observations of the Ring Nebula by NASA's Hubble Space Telescope, however, reveal a new twist on an iconic nebula.
The Hubble images offer the best view yet of the nebula, revealing a complex structure. The observations have allowed astronomers to construct the most precise three-dimensional model of the glowing gas shroud, called a planetary nebula. Based on the new observations, the Hubble research team suggests that the ring wraps around a blue football-shaped structure that protrudes out of opposite sides of the ring. The nebula is tilted toward Earth so that astronomers see the ring face-on.
Rare Stellar Alignment Offers Opportunity to Hunt for Planets
The ancients thought that stars were fixed pinpoints of light on the sky. Today we know that they are all moving, like fish in a pond. This so-called proper motion is so small that it is not noticeable to the human eye over a single lifetime. But Hubble can precisely track stellar motions to razor-sharp precision. Not surprisingly the nearest star to our Sun, Proxima Centauri, is one of the fastest moving across the sky. Hubble astronomers have found that it will pass in front of two far-more distant background stars, once in 2014 and again in 2016. This will afford a very rare opportunity to see how Proxima's gravity warps the image of the background stars by bending their light. This effect, called gravitational lensing, can be used to estimate Proxima Centauri's mass and establish the presence of any planets orbiting the star.
Hubble Maps 3-D Structure of Ejected Material Around Erupting Star
After 45 years of peaceful bliss, the nova T Pyxidis erupted again in 2011. Astronomers took advantage of a flash of light accompanying the blast to map the ejecta from previous outbursts surrounding the double-star system. The team used NASA's Hubble Space Telescope to trace the light as it sequentially illuminated different parts of the disk, a phenomenon called a light echo. Contrary to some predictions, the astronomers were somewhat surprised to find that the ejecta stayed in the vicinity of the star and formed a disk of debris. The discovery suggests that material continues expanding outward along the system's orbital plane, but it does not escape the system.
Hubble Uncovers Evidence for Extrasolar Planet Under Construction
Nearly 900 extrasolar planets have been confirmed to date, but now for the first time astronomers think they are seeing compelling evidence for a planet under construction in an unlikely place, at a great distance from its diminutive red dwarf star.
The keen vision of NASA's Hubble Space Telescope has detected a mysterious gap in a vast protoplanetary disk of gas and dust swirling around the nearby star TW Hydrae, located 176 light-years away in the constellation Hydra (the Sea Serpent). The gap's presence is best explained as due to the effects of a growing, unseen planet that is gravitationally sweeping up material and carving out a lane in the disk, like a snow plow.
What looks like a celestial hummingbird is really the result of a collision between a spiral and an elliptical galaxy at a whopping 326 million light- years away. The flat disk of the spiral NGC 2936 is warped into the profile of a bird by the gravitational tug of the companion NGC 2937. The object was first cataloged as a "peculiar galaxy" by Halton Arp in the 1960s. This interacting galaxy duo is collectively called Arp 142.
This July 4th, the solar system is showing off some fireworks of its own. Superficially resembling a skyrocket, Comet ISON is hurtling toward the Sun at a whopping 48,000 miles per hour. Unlike a firework, the comet is not combusting, but in fact is pretty cold. Its skyrocket-looking tail is really a streamer of gas and dust bleeding off the icy nucleus. The video shows a sequence of Hubble observations taken over a 43-minute span, compressed into just five seconds. The comet travels 34,000 miles during the exposure sequence.
Hubble has identified the true visible-light color of a giant Jupiter-sized planet located 63 light-years away. The planet has a cobalt blue color. It has torrential 4,500-mile-per-hour winds that are so hot they melt silicates into raindrops of molten glass. And that's where the cobalt-blue hue comes from, not oceans. The glass droplets scatter blue light more readily than green or red light.
The planet's color provides unique clues to the atmosphere and weather on a truly alien world that orbits much closer to its star than the innermost planet Mercury is to our Sun.
