Asteroid with energy of three Hiroshima bombs explodes over Indonesia

NASA's IBEX (Interstellar Boundary Explorer) spacecraft has made the first all-sky map of the heliosphere and the results have taken researchers by surprise. The map is bisected by a bright, winding ribbon of unknown origin:

"This is a shocking new result," says IBEX principal investigator Dave McComas of the Southwest Research Institute. "We had no idea this ribbon existed--or what has created it. Our previous ideas about the outer heliosphere are going to have to be revised."

The two Voyager spacecraft (labeled V1 and V2 in the figure) have spent decades traveling to the edge of the solar system for in situ inspection of whatever might be there--but ironically both spacecraft missed the ribbon. "It's like having two weather stations, but missing the big storm that runs between them," says Eric Christian, IBEX deputy mission scientist at NASA's Goddard Space Flight Center.

At the moment, theorists are "working like crazy" to understand this discovery and how the ribbon might affect the ability of the heliosphere to shield us from cosmic rays. Science@NASA has the full story.

HERE IS THE FOLLOWUP STORY:

Giant Ribbon at the Edge of the Solar System: Mystery Solved? 01.15.2010     January 15, 2010: Last year, when NASA's IBEX (Interstellar Boundary Explorer) spacecraft discovered a giant ribbon at the edge of the solar system, researchers were mystified. They called it a "shocking result" and puzzled over its origin. Now the mystery may have been solved. "We believe the ribbon is a reflection," says Jacob Heerikhuisen, a NASA Heliophysics Guest Investigator from the University of Alabama in Huntsville. "It is where solar wind particles heading out into interstellar space are reflected back into the solar system by a galactic magnetic field." Heerikhuisen is the lead author of a paper reporting the results in the Jan. 10th edition of the Astrophysical Journal Letters. Right: An artist's concept of the Interstellar Boundary Explorer (IBEX). "This is an important finding," says Arik Posner, IBEX program scientist at NASA Headquarters. "Interstellar space just beyond the edge of the solar system is mostly unexplored territory. Now we know, there could be a strong, well-organized magnetic field sitting right on our doorstep." The IBEX data fit in nicely with recent results from Voyager. Voyager 1 and 2 are near the edge of the solar system and they also have sensed strong* magnetism nearby. Voyager measurements are relatively local to the spacecraft, however. IBEX is filling in the "big picture." The ribbon it sees is vast and stretches almost all the way across the sky, suggesting that the magnetic field behind it must be equally vast. Although maps of the ribbon (see below) seem to show a luminous body, the ribbon emits no light. Instead, it makes itself known via particles called "energetic neutral atoms" (ENAs)--mainly garden-variety hydrogen atoms. The ribbon emits these particles, which are picked up by IBEX in Earth orbit. Above: A comparison of IBEX observations (left) with a 3D magnetic reflection model (right). More images: data, model. The reflection process posited by Heerikhuisen et al. is a bit complicated, involving multiple "charge exchange" reactions between protons and hydrogen atoms. The upshot, however, is simple. Particles from the solar wind that escape the solar system are met ~100 astronomical units (~15 billion kilometers) away by an interstellar magnetic field. Magnetic forces intercept the escaping particles and sling them right back where they came from. "If this mechanism is correct--and not everyone agrees--then the shape of the ribbon is telling us a lot about the orientation of the magnetic field in our corner of the Milky Way galaxy," notes Heerikhuisen. And upon this field, the future may hinge. The solar system is passing through a region of the Milky Way filled with cosmic rays and interstellar clouds. The magnetic field of our own sun, inflated by the solar wind into a bubble called the "heliosphere," substantially protects us from these things. However, the bubble itself is vulnerable to external fields. A strong magnetic field just outside the solar system could press against the heliosphere and interact with it in unknown ways. Will this strengthen our natural shielding—or weaken it? No one can say. Right: An artist's concept of interstellar clouds in the galactic neighborhood of the sun. [more] "IBEX will monitor the ribbon closely in the months and years ahead," says Posner. "We could see the shape of the ribbon change—and that would show us how we are interacting with the galaxy beyond." It seems we can learn a lot by looking in the mirror. Stay tuned to Science@NASA for updates. Author: Dr. Tony Phillips | Credit: Science@NASA more information and footnotes   IBEX home page -- (NASA) IBEX mission page -- (SWRI) Footnote: * The strong interstellar fields mentioned in this story measure about ~5 microgauss. A microgauss is one millionth of a gauss, a unit of magnetic field strength popular among astronomers and geophysicists. Earth's magnetic field is about 0.5 gauss or 500,000 microgauss. Magnetic fields pervading interstellar space tend to be much less intense than planetary magnetic fields. Credits: The IBEX spacecraft was launched in October 2008. Its science objective was to discover the nature of the interactions between the solar wind and the interstellar medium at the edge of our solar system. The Southwest Research Institute developed and leads the mission with a team of national and international partners. The spacecraft is the latest in NASA's series of low-cost, rapidly developed Small Explorers Program. NASA's Goddard Space Flight Center manages the program for the agency's Science Mission Directorate at NASA Headquarters in Washington.

Thirty-eight and a half years old, to be exact. The crater was formed on February 4, 1971, by the impact of Apollo 14's Saturn IVB booster rocket. NASA intentionally guided the rocket into the lunar surface to provide a signal for seismometers deployed by Apollo astronauts. The experiment yielded new information about the Moon's interior structure.

Over the years, NASA and other international space agencies have peppered the Moon with dozens of spacecraft--usually on purpose, although not always--and by doing so gained considerable experience with the results of lunar impacts. Researchers tapped into that experience when they predicted bright flashes and debris plumes for the crash of LCROSS. Imagine their surprise when the flashes and plumes failed to materialize! To the human eye, LCROSS and its Centaur booster rocket simply disappeared into the inky depths of Cabeus with no obvious evidence of impact.

The solution to this mystery probably lies in data beamed back to Earth by LCROSS in the last minutes before impact. Scientists are crunching the numbers, and it may be days or weeks before results are known. Stay tuned.

SOLAR ACTIVITY: NASA's STEREO spacecraft and the Solar and Heliospheric Observatory (SOHO) are monitoring an active region about to emerge over the sun's southeastern limb: image. Readers with solar telescopes are encouraged to keep an eye on the region for signs of a possible sunspot.

MYSTERY OF THE MISSING PLUMES: NASA scientists are grappling with a mystery. Where did the debris go? Last Friday morning, Oct. 9th, the water-seeking LCROSS spacecraft and its Centaur booster rocket crashed into the floor of crater Cabeus near the Moon's south pole, on time and on target. But the debris plumes that were supposed to issue from the impacts failed to materialize. Consider this image recorded 15 seconds after the Centaur impact by the Palomar Observatory's 200-inch Hale telescope:

Click to view a 12-minute mpg movie.

Cabeus crater is located in the center, behind the large bright mountain. Plumes of shattered spacecraft and lunar soil should have emerged into sunlight from the shadows, but even Palomar's sensitive adaptive optics system registered nothing.

The absence of debris plumes does not mean LCROSS was a failure. On the contrary, by offering up the unexpected, LCROSS is teaching us something new about the lunar surface and the products of lunar impacts. That makes it, by definition, a successful experiment. All that remains is to figure out what the new information is. Researchers will be announcing their findings in the days and weeks ahead.

NASA PHOTO

"I was a little disappointed not seeing a flash and a plume. Maybe LCROSS hit mud!" he laughs. "I hope the spacecraft's cameras saw something we missed."

Indeed they did. When the Centaur hit the crater floor, infrared cameras onboard the LCROSS mothership recorded a flash of heat and spectrometers detected sodium in the debris cloud. The appearance of sodium was a surprise--perhaps the first of many to come from this unprecedented experiment. Mission scientists have not yet had a chance to fully examine the LCROSS spectra for signs of water, but "we will be working on this feverishly today," said mission leader Tony Colaprete at a post-impact NASA press conference.

The low brightness of the flash did not dim the enthusiasm of thousands of people around the world who stayed up late for lunar impact parties. At the Sci-Quest science museum in Huntsville, Alabama, about a hundred kids and parents gathered to watch the show. "We donned our party hats, blew our noise makers and waited for the impact," says science writer Dauna Coulter. NASA photographer David Higginbotham documented the scene:

What happened to the L-Cross impactor?  The camera showed nothing except the crater getting closer and closer. It didn't  show the impactor throw up dust -  it showed nothing and then went blank.  It'll be interesting to hear the disinfo coming from NASA in the next few hours.

LUNAR IMPACT! NASA's LCROSS spacecraft and its Centaur booster rocket have hit the lunar surface. The impact flash from the Centaur booster rocket was not bright--it has been described "a dud" visually--but mission scientists say that could be good news, indicative of an impact in loose, relatively water-rich regolith. Mission scientists will share first images and results aer in tandem with other human beings.  They are not claiming that the L-Cross impactor itself was a success. On the NASA feed, the scientists are making excuse after excuse that we didn't see anything, including that they didn't look at it themselves yet.

The scientist says he is happy with the images of the camera, and he is proud of the camera.

Whoopee!  $79 million dollars to be proud of a camera.

This morning, amateur astronomer Pete Lawrence photographed the impact site from his backyard observatory in Selsey UK. The red dot marks the spot:

"I used NASA's pointing chart to find target crater Cabeus," says Lawrence.

NASA hopes many amateur astronomers will be watching on Friday. "The more eyes the better," says LCROSS team member Brian Day of NASA/Ames. "We've never done this before and surprises are possible." US sky watchers west of the Mississippi river are favored with darkness and good views of the Moon at the time of the impacts.

To observers on Earth, the initial flashes of light marking the destruction of the two spacecraft will be hidden by crater walls. The debris plumes, however, should be visible in 10-inch class telescopes as they rise 10 km high above the rim of Cabeus. Note the shadows behind the red dot in Lawrence's image. The sunlit plumes will be highlighted by that dark backdrop: observing tips.

The impacts are designed to excavate frozen water from the cold and shadowy floor of crater Cabeus. Moon water is valuab money for future thirsty colonists. H₂O also can be split into O₂ for breathing and H₂ for rocket fuel.

Evidence of water will be sought in the plumes of debris that billow out of Cabeus. The Hubble Space Telescope, NASA's Lunar Reconnaissance Orbiter, and several great telescopes on Earth will monitor the plumes for spectral signs of water (H₂O) or water fragments (OH). Some results could be available only hours after the impacts, so stay tuned.

Lunar Impact Resources:

• Lunar Impact Viewer's Guide -- from Science@NASA
• Lunar Impact Animation -- a computer-generated view of the impacts
• Google's LCROSS Observer's Group -- observing tips and mission updates
• NASA's Citizen Science Site -- share your images with scientists
• Spaceweather's Image Submission Tool -- share your images with the world!

to launch a 28 MB Quicktime movie:

In the movie, STEREO-A's view appears on the right, STEREO-B's on the left. From one side, the filament appears dark and shadowy, backlit by the fiery surface of the sun below. From the other side, the filament itself appears fiery, outlined by the dark backdrop of space beyond the sun. Astronomers have never seen solar activity in this way before, and there is much to be learned from the increasingly complete view STEREO provides. More images may be found in the STEREO Selects photo gallery.

Spitzer Discovers Saturn's Largest Ring10.07.2009

October 7, 2009: NASA's Spitzer Space Telescope has discovered an enormous and previously unknown infrared ring around Saturn.

"This is one supersized ring," says Anne Verbiscer, an astronomer at the University of Virginia, Charlottesville. "If you could see the ring in the night sky, it would span the width of two full Moons."

Verbiscer is co-author of a paper about the discovery to be published online tomorrow by the journal Nature. The other authors are Douglas Hamilton of the University of Maryland and Michael Skrutskie of the University of Virginia.

Above: An artist's concept of the newly-discovered infrared ring around Saturn. [more]

The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane. The bulk of its material starts about six million kilometers (3.7 million miles) away from the planet and extends outward roughly another 12 million kilometers (7.4 million miles). It would take about one billion Earths stacked together to fill the voluminous ring. One of Saturn's farthest moons, Phoebe, circles within the newfound ring, and is likely the source of its material.

The discovery may help solve an age-old riddle of one of Saturn's moons. Iapetus has a strange appearance — one side is bright and the other is really dark, in a pattern that resembles the yin-yang symbol. The astronomer Giovanni Cassini first spotted the moon in 1671, and years later figured out it has a dark side, now named Cassini Regio in his honor.

Saturn's supersized ring could explain how Cassini Regio came to be so dark. The ring is circling in the same direction as Phoebe, while Iapetus, the other rings and most of Saturn's moons are all going the opposite way. According to the scientists, some of the dark and dusty material from the outer ring moves inward toward Iapetus, slamming the icy moon like bugs on a windshield.

"Astronomers have long suspected that there is a connection between Saturn's outer moon Phoebe and the dark material on Iapetus," said Hamilton. "This new ring provides [the missing link]."

Saturn's moon Iapetus. One side of the moon is darkened as the moon plows through the dust of Saturn's newly-discovered infrared ring. [more]

Verbiscer and colleagues used Spitzer's longer-wavelength infrared camera, called the multiband imaging photometer, to scan through a patch of sky far from Saturn and a bit inside Phoebe's orbit. The astronomers had a hunch that Phoebe might be circling around in a belt of dust and, sure enough, when the scientists took a first look at their Spitzer data, a band of dust jumped out.

The ring would be difficult to see with visible-light telescopes. The relatively small numbers of particles in the ring wouldn't reflect much visible light, especially out at Saturn where sunlight is weak.

"The particles are so far apart that if you were to stand in the ring, you wouldn't even know it," said Verbiscer. "By focusing on the glow of the ring's cool dust, Spitzer made it easy to find."

For additional images relating to the ring discovery and more
information about Spitzer, visit http://www.spitzer.caltech.edu.

Editor: Dr. Tony Phillips | Credit: Science@NASA

One way to know you've found the right crater: It'll be the one with an fluffy plume on Friday morning. Mission scientists expect debris from the double-impact of LCROSS and its booster rocket to rise about 7 kilometers over the rim of Cabeus. There will be two plumes, one from the booster rocket (4:30 am PDT) and another from the LCROSS mothership (4:34 am PDT). Each is expected to linger in sunlight for 60 to 90 seconds before falling back into the shadowy depths of Cabeus. The surface brightness of the plumes should be similar to that of surrounding sunlit terrain.

More Lunar Impact Resources:

• LCROSS Slideshow -- observing tips for backyard astronomers
• Cabeus Pointing Chart -- a detailed chart with waypoints and coordinates
• Google's LCROSS Observer's Group -- more observing tips and mission updates

October 5, 2009: Just imagine. A spaceship plunges out of the night sky, hits the ground and explodes. A plume of debris billows back into the heavens, leading your eye to a second ship in hot pursuit. Four minutes later, that one hits the ground, too. It's raining spaceships!

Put on your hard hat and get ready for action, because on Friday, Oct. 9th, what you just imagined is really going to happen--and you can have a front row seat.

A computer visualization of LCROSS hitting the Moon on Oct. 9th. Credit: NASA/Ames

The impact site is crater Cabeus near the Moon's south pole. NASA is guiding the Lunar Crater Observation and Sensing Satellite ("LCROSS" for short) and its Centaur booster rocket into the crater's floor for a spectacular double-impact designed to "unearth" signs of lunar water.

First, turn on NASA TV. The space agency will broadcast the action live from the Moon, with coverage beginning Friday morning at 3:15 am PDT (10:15 UT). The first hour or so, pre-impact, will offer expert commentary, status reports from mission control, camera views from the spacecraft, and telemetry-based animations.
 

The actual impacts commence at 4:30 am PDT (11:30 UT). The Centaur rocket will strike first, transforming 2200 kg of mass and 10 billion joules of kinetic energy into a blinding flash of heat and light. Researchers expect the impact to throw up a plume of debris as high as 10 km.

Close behind, the LCROSS mothership will photograph the collision for NASA TV and then fly right through the debris plume. Onboard spectrometers will analyze the sunlit plume for signs of water (H₂O), water fragments (OH), salts, clays, hydrated minerals and assorted organic molecules.

"If there's water there, or anything else interesting, we'll find it," says Tony Colaprete of NASA Ames, the mission's principal investigator.

Above: The lunar south pole as it will appear on the night of impact. Photo Credit - NMSU / MSFC Tortugas Observatory.

Next comes the mothership's own plunge. Four minutes after the Centaur "lands," the 700 kg LCROSS satellite will strike nearby, sending another, smaller debris plume over the rim of Cabeus.

The Hubble Space Telescope, the Lunar Reconnaissance Orbiter (LRO), and hundreds of telescopes great and small on Earth will scrutinize the two plumes, looking for signs of water and the unexpected.

And that brings us to the second way to see the show: Grab your telescope.

"We expect the debris plumes to be visible through mid-sized backyard telescopes—10 inches and larger," says Brian Day of NASA/Ames. Day is an amateur astronomer and the Education and Public Outreach Lead for LCROSS. "The initial explosions will probably be hidden behind crater walls, but the plumes will rise high enough above the crater's rim to be seen from Earth."

The Pacific Ocean and western parts of North America are favored with darkness and a good view of the Moon at the time of impact. Hawaii is the best place to be, with Pacific coast states of the USA a close second. Any place west of the Mississippi River, however, is a potential observing site.

 The side of Earth facing the Moon at the time of impact. [larger image] [observing tips]

When the plumes emerge from Cabeus, they will be illuminated by sunshine streaming over the polar terrain. The crater itself will be in the dark, however, permanently shadowed by its own walls. "That's good," says Day. "The crater's shadows will provide a dark backdrop for viewing the sunlit plumes."

In an earlier stage of mission planning, scientists hoped to strike a crater closer to the Moon's limb so that the plumes would billow out against the dark night sky, providing maximum contrast for observers on Earth. However, recent data from NASA's Lunar Reconnaissance Orbiter, Japan's Kaguya spacecraft and India's Chandrayaan-1 probe altered those plans.

"We've just learned that Cabeus may contain relatively-rich deposits of hydrogen and/or frozen water," says Colaprete. "Cabeus is not as close to the lunar limb as we would have liked, but it seems to offer us the best chance of hitting H₂O."

The LCROSS team hopes many people—amateurs and professionals alike—will observe and photograph the plumes. "The more eyes the better," says Day. "Remember, we've never done this before. We're not 100% sure what will happen, and big surprises are possible."

Public Viewing Events List

http://www.nasa.gov/mission_pages/LCROSS/impact/event_index.html

Veteran amateur astronomer Kurt Fisher has prepared a 13 MB slideshow to help fellow amateurs locate and witness the plumes: download it . There is also an online LCROSS observer's group where novices can read introductory articles and chat with other observers.

"This is a wonderful opportunity for citizen scientists to join NASA in the process of discovery," says Day, who urges observers to submit their images to the LCROSS Citizen Science Site. "It's a great adventure, and anyone can participate."

Imagine that.

Author: Dr. Tony Phillips | Credit: Science@NASA

Sun prominence dancing along the edge of the sun

Readers with solar telescopes, train your optics on the sun's northwestern limb.

more images: from John Minnerath of Crowheart, Wyoming; from Mike Borman of Evansville, Indiana; from Steve Riegel of Santa Maria, California; from Fabio Mariuzza of Biauzzo - Italy; from Peter Paice of Belfast, Northern Ireland; from Mark Townley of Brierley Hill, West Midlands, UK; from Fabio Mariuzza of Biauzzo - Italy

Current conditions

The arc-shaped depression in the crater's floor is a "pit crater." A few of these have been seen on Mercury, and they are probably volcanic in nature. Pit craters may have formed when subsurface magma drained away and left a roof area unsupported, leading to collapse and the formation of the pit. In this example, the southern area of the pit appears to have two or more floor levels. The discovery of multiple pit-floor craters adds to a growing body of evidence that volcanic activity was widespread in Mercury's past.

Stay tuned for more happy discoveries.