September 10, 2010
A Ghostly Cosmic Pinwheel
Somewhere in Pegasus, a swollen, aging star has begun its death spiral figuratively and literally — throwing off matter that's taken the shape of a delicate yet perfect spiral.
After looking at 20 years' worth of fabulous pictures from the Hubble Space Telescope, you might get the feeling that each new release is a variation on a theme you've seen before: a supernova remnant, interacting galaxies, new stars cocooned in their placental nebulas, and so on.
But this is something different!
The dim spiral in this image is almost spooky in its perfect symmetry. The view was captured several years ago by HST's Advanced Camera for Surveys, but a few days ago it came to light (ouch! pun alert!) on a European website devoted to Hubble's discoveries.
"So what is it?" you ask. First, I can tell you that it's real (not an artifact), it's about 3,000 light-years away in Pegasus, and it's not associated with the bright foreground star to its right.
After looking at 20 years' worth of fabulous pictures from the Hubble Space Telescope, you might get the feeling that each new release is a variation on a theme you've seen before: a supernova remnant, interacting galaxies, new stars cocooned in their placental nebulas, and so on.
But this is something different!
The dim spiral in this image is almost spooky in its perfect symmetry. The view was captured several years ago by HST's Advanced Camera for Surveys, but a few days ago it came to light (ouch! pun alert!) on a European website devoted to Hubble's discoveries.
"So what is it?" you ask. First, I can tell you that it's real (not an artifact), it's about 3,000 light-years away in Pegasus, and it's not associated with the bright foreground star to its right.
August 20, 2010
A New Twist on Dark Energy
The notion that a massive object can literally bend light, what we now call gravitational lensing, has been around for more than 200 years — though Einstein gets the nod for making the effect widely known.
Ever since the 1979 discovery of a distant quasar "lensed" by an intervening galaxy, observers have amassed all sorts of gravitationally mangled novelties — none more famous than QSO 2237+0305, the Einstein Cross. By carefully dissecting these cosmic mirages, cosmologists can learn much about the "lenses" in the foreground (such as how much unseen dark matter is fortifying their mass) and about the distances to the objects being distorted.
Careful observations of the galaxy cluster Abell 1869, so massive that it bends the light from dozens of distant galaxies, have given cosmologists a powerful new tool in their quest to understand dark energy.
Ever since the 1979 discovery of a distant quasar "lensed" by an intervening galaxy, observers have amassed all sorts of gravitationally mangled novelties — none more famous than QSO 2237+0305, the Einstein Cross. By carefully dissecting these cosmic mirages, cosmologists can learn much about the "lenses" in the foreground (such as how much unseen dark matter is fortifying their mass) and about the distances to the objects being distorted.
Careful observations of the galaxy cluster Abell 1869, so massive that it bends the light from dozens of distant galaxies, have given cosmologists a powerful new tool in their quest to understand dark energy.
August 17, 2010
Fermi detects shocking surprise from supernova's little cousin
Astronomers using NASA's Fermi Gamma-ray Space Telescope have detected gamma rays from a nova for the first time, a finding that stunned observers and theorists alike. The discovery overturns the notion that nova explosions lack the power to emit such high-energy radiation.
A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion.
"In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the Sun every year," said Elizabeth Hays, from NASA's Goddard Space Flight Center in Greenbelt, Maryland. "But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly."
A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion.
"In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the Sun every year," said Elizabeth Hays, from NASA's Goddard Space Flight Center in Greenbelt, Maryland. "But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly."
August 14, 2010
Asteroid Near Neptune Found in Gravitational Dead Zone
Astronomers have discovered a new asteroid in a region of Neptune's orbit where no previous object was known to exist -- a so-called gravitational "dead zone."
The asteroid, which follows Neptune's orbit around the sun, may help shed light on fundamental questions about planetary formation and migration.
The asteroid, classified as a Trojan, was found in a difficult-to-detect area near Neptune, known as the Lagrangian point L5. Lagrangian points are five areas in space where the gravitational tugs from two relatively massive bodies -- such as Neptune and the sun -- balance out. This allows smaller bodies, like asteroids, to remain stable and fixed in synch with the planet's orbit, as they orbit the sun.
The asteroid, which follows Neptune's orbit around the sun, may help shed light on fundamental questions about planetary formation and migration.
The asteroid, classified as a Trojan, was found in a difficult-to-detect area near Neptune, known as the Lagrangian point L5. Lagrangian points are five areas in space where the gravitational tugs from two relatively massive bodies -- such as Neptune and the sun -- balance out. This allows smaller bodies, like asteroids, to remain stable and fixed in synch with the planet's orbit, as they orbit the sun.
August 10, 2010
Discovery of Saturn’s Auroral Heartbeat
An international team of scientists led by Dr Jonathan Nichols of the University of Leicester has discovered that Saturn's aurora, an ethereal ultraviolet glow which illuminates Saturn's upper atmosphere near the poles, pulses roughly once per Saturnian day.
The length of a Saturnian day has been under much discussion since it was discovered that the traditional 'clock' used to measure the rotation period of Saturn, a gas giant planet with no solid surface for reference, apparently does not keep good time.
Saturn, like all magnetised planets, emits radio waves into space from the polar regions. These radio emissions pulse with a period near to 11 h, and the timing of the pulses was originally, during the Voyager era, thought to represent the rotation of the planet. However, over the years the period of the pulsing of the radio emissions has varied, and since the rotation of a planet cannot be easily sped up or slowed down, the hunt for the source of the varying radio period has become one of the most perplexing puzzles in planetary science.
The length of a Saturnian day has been under much discussion since it was discovered that the traditional 'clock' used to measure the rotation period of Saturn, a gas giant planet with no solid surface for reference, apparently does not keep good time.
Saturn, like all magnetised planets, emits radio waves into space from the polar regions. These radio emissions pulse with a period near to 11 h, and the timing of the pulses was originally, during the Voyager era, thought to represent the rotation of the planet. However, over the years the period of the pulsing of the radio emissions has varied, and since the rotation of a planet cannot be easily sped up or slowed down, the hunt for the source of the varying radio period has become one of the most perplexing puzzles in planetary science.
August 3,2010
Spectacular Northern Lights Show Signals Sun Is Waking Up
Skywatchers at high latitudes could be in for a spectacular treat of northern lights, the aurora borealis, Tuesday and Wednesday: After a relatively quiet stretch, it appears the sun is ramping up its activity.
The sun's surface erupted early Sunday, blasting tons of plasma (ionized atoms) into space. These atoms are headed toward Earth and could create a stunning light show in the process.
"This eruption is directed right at us and is expected to get here early in the day on Aug. 4th," said Leon Golub of the Harvard-Smithsonian Center for Astrophysics. "It's the first major Earth-directed eruption in quite some time."
July 29, 2010
The August Mars Hoax Is Back
It's almost August, and you know what that means. The August Mars Hoax is starting to go around again.
Actually, "hoax" is the wrong word for this thing, unless some joker is now spreading it knowingly (quite possible). It's an e-mail chain letter claiming that Mars will come closer than ever in history on August 23rd and will look as big as the full Moon. If your well-meaning great-aunt or your cousin's brother-in-law's dog hasn't sent it to you, it's probably just a matter of time.
Actually, "hoax" is the wrong word for this thing, unless some joker is now spreading it knowingly (quite possible). It's an e-mail chain letter claiming that Mars will come closer than ever in history on August 23rd and will look as big as the full Moon. If your well-meaning great-aunt or your cousin's brother-in-law's dog hasn't sent it to you, it's probably just a matter of time.
July 26, 2010
Hyperfast star was booted from Milky Way
A hundred million years ago, a triple-star system was traveling through the bustling center of our Milky Way Galaxy when it made a life-changing misstep. The trio wandered too close to the galaxy's giant black hole, which captured one of the stars and hurled the other two out of the Milky Way. The two outbound stars merged to form a super-hot blue star.
Astronomers using NASA's Hubble Space Telescope said it is the most likely scenario for a hypervelocity star known as HE 0437-5439, one of the fastest ever detected. It is blazing across space at a speed of 1.6 million mph (2.5 million km/h), 3 times faster than our Sun's orbital velocity in the Milky Way. Hubble observations confirm that the stellar speedster comes from the Milky Way's core, settling some confusion over where it originally came from.
Astronomers using NASA's Hubble Space Telescope said it is the most likely scenario for a hypervelocity star known as HE 0437-5439, one of the fastest ever detected. It is blazing across space at a speed of 1.6 million mph (2.5 million km/h), 3 times faster than our Sun's orbital velocity in the Milky Way. Hubble observations confirm that the stellar speedster comes from the Milky Way's core, settling some confusion over where it originally came from.
July 25, 2010
Scorched Alien Planet Has a Comet Tail
A scorched alien planet is flying so close to its parent star that its atmosphere is being swept off it in a glowing tail like some sort of giant comet, NASA announced Thursday.
The existence of the planet and its strange tail, which was suggested in previous studies, was confirmed recently by NASA's Hubble Space Telescope. These new observations of the gas giant planet, called HD 209458b, suggest strong winds from its nearby star are blowing the atmosphere off the scorched world and shaping it into a comet-like tail.
The existence of the planet and its strange tail, which was suggested in previous studies, was confirmed recently by NASA's Hubble Space Telescope. These new observations of the gas giant planet, called HD 209458b, suggest strong winds from its nearby star are blowing the atmosphere off the scorched world and shaping it into a comet-like tail.
July 21, 2010
Record-breaking X-ray blast briefly blinds space observatory
A blast of the brightest X-rays ever detected from beyond our Milky Way Galaxy's neighborhood temporarily blinded the X-ray eye on NASA's Swift space observatory earlier this summer. The X-rays traveled through space for 5 billion years before slamming into and overwhelming Swift's X-ray Telescope June 21. The blindingly bright blast came from a gamma-ray burst, a violent eruption of energy from the explosion of a massive star morphing into a new black hole.
July 18, 2010
Star Nursery Photographed in Vivid Colors
A roiling interstellar cloud and filled with newborn stars shines in vivid colors in a newly released snapshot from the Hubble Space Telescope.
The wispy pink and yellow cloud in the new Hubble photo, which scientists released Tuesday, is made of mostly hydrogen gas heated by fierce ultraviolet radiation from the new stars at its heart. The cloud, called NGC 2467, lies in the southern constellation of Puppis about 13,000 light-years from Earth.
The stars form when gas in the cloud condenses under its own gravity and becomes packed enough to ignite nuclear fusion. Bright blue dots represent hot young stars in the photo, which includes observations taken from 2004.
The wispy pink and yellow cloud in the new Hubble photo, which scientists released Tuesday, is made of mostly hydrogen gas heated by fierce ultraviolet radiation from the new stars at its heart. The cloud, called NGC 2467, lies in the southern constellation of Puppis about 13,000 light-years from Earth.
The stars form when gas in the cloud condenses under its own gravity and becomes packed enough to ignite nuclear fusion. Bright blue dots represent hot young stars in the photo, which includes observations taken from 2004.
July 14, 2010
Giant Propellers Discovered In Saturn's Rings
Giant propeller-shaped structures have been discovered in the rings of Saturn and appear to be created by a new class of hidden moons, NASA announced Thursday.
NASA's Cassini spacecraft spotted the distinctive structures inside some of Saturn's rings, marking the first time scientists have managed to track the orbits of individual objects from within a debris disk like the one that makes up Saturn's complicated ring system.
NASA's Cassini spacecraft spotted the distinctive structures inside some of Saturn's rings, marking the first time scientists have managed to track the orbits of individual objects from within a debris disk like the one that makes up Saturn's complicated ring system.
July 12, 2010
Black Hole Blows Massive Gas Bubble
A newfound black hole has been caught in the act of releasing a prodigious amount of energy from the most powerful pair of jets ever seen from such a cosmic object. But the real surprise is what is created by those jets.
July 12, 2010
Rosetta Visits a Big Space Rock
A European-built comet chaser swept past asteroid 21 Lutetia today, offering glimpses of what might be a largely metallic body that's 100 miles across.
This is Rosetta's second such flyby. It flew past 4-mile-wide 2867 Steins on September 5, 2008, a useful visit that was marred by problems with the high-resolution camera. The spacecraft has also brushed past Earth three times (most recently last November 13th) and Mars once.
This is Rosetta's second such flyby. It flew past 4-mile-wide 2867 Steins on September 5, 2008, a useful visit that was marred by problems with the high-resolution camera. The spacecraft has also brushed past Earth three times (most recently last November 13th) and Mars once.