Archive for October 6th, 2009

An artist’s concept of a new found ring around Saturn. Details on the image and the finding of the ring below.

This artist’s conception simulates an infrared view of the giant ring. Saturn appears as just a small dot from outside the band of ice and dust. The bulk of the ring 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). The ring’s diameter is equivalent to roughly 300 Saturns lined up side to side.

The inset shows an enlarged image of Saturn, as seen by the W.M. Keck Observatory at Mauna Kea, Hawaii, in infrared light. The ring, stars and wispy clouds are an artist’s representation.

Image credit: NASA/JPL-Caltech/Keck

PASADENA, Calif. — NASA’s Spitzer Space Telescope has discovered an enormous ring around Saturn — by far the largest of the giant planet’s many rings.

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). One of Saturn’s farthest moons, Phoebe, circles within the newfound ring, and is likely the source of its material.

Saturn’s newest halo is thick, too — its vertical height is about 20 times the diameter of the planet. It would take about one billion Earths stacked together to fill the ring.

“This is one supersized ring,” said Anne Verbiscer, an astronomer at the University of Virginia, Charlottesville. “If you could see the ring, it would span the width of two full moons’ worth of sky, one on either side of Saturn.” Verbiscer; Douglas Hamilton of the University of Maryland, College Park; and Michael Skrutskie, of the University of Virginia, Charlottesville, are authors of a paper about the discovery to be published online tomorrow by the journal Nature.

The ring itself is tenuous, made up of a thin array of ice and dust particles. Spitzer’s infrared eyes were able to spot the glow of the band’s cool dust. The telescope, launched in 2003, is currently 107 million kilometers (66 million miles) from Earth in orbit around the sun.

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. A stunning picture of Iapetus taken by NASA’s Cassini spacecraft is online at http://photojournal.jpl.nasa.gov/catalog/PIA08384.

Saturn’s newest addition could explain how Cassini Regio came to be. 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 convincing evidence of that relationship.”

Verbiscer and her 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 kicked up from its minor collisions with comets — a process similar to that around stars with dusty disks of planetary debris. 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. Its particles are diffuse and may even extend beyond the bulk of the ring material all the way in to Saturn and all the way out to interplanetary space. 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.

Spitzer was able to sense the glow of the cool dust, which is only about 80 Kelvin (minus 316 degrees Fahrenheit). Cool objects shine with infrared, or thermal radiation; for example, even a cup of ice cream is blazing with infrared light. “By focusing on the glow of the ring’s cool dust, Spitzer made it easy to find,” said Verbiscer.

These observations were made before Spitzer ran out of coolant in May and began its “warm” mission.

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. The multiband imaging photometer for Spitzer was built by Ball Aerospace Corporation, Boulder, Colo., and the University of Arizona, Tucson. Its principal investigator is George Rieke of the University of Arizona.

Two storms, very near each other. Taken with two different satellites, details below.

Once a powerful Super Typhoon, Parma crossed over the northern tip of Luzon Island, the Philippines, on October 3, 2009, as a Category 1 typhoon. The storm battered the island with damaging winds and heavy rain before moving over the South China Sea, where it stalled, spinning more or less in place for about a day and a half. On October 6, the storm reversed direction and moved southeast back over Luzon. What caused this change in direction? The answer is shown in this true color image from October 6. The powerful Super Typhoon Melor moved close enough to Parma to influence its motion.

When two cyclones approach one another, they can interact in a variety of ways. One interaction is the Fujiwara Effect, in which the two storms are drawn together and begin to circle around each other. In this case, Parma was drawn towards the stronger Melor. Occasionally, the stronger storm will absorb the weaker storm, but that fate wasn’t in the forecast for Parma as of October 6. The Joint Typhoon Warning Center expected Parma to move south away from Melor and eventually track west over the South China Sea on October 8.

This image blends two satellite overpasses to show the proximity of the two storms to one another. The left half of the image, containing Tropical Storm Parma, is from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, acquired at 10:35 a.m., Philippine time. The right half of the image was taken just under two hours later (Philippine time) by the MODIS instrument on NASA’s Aqua satellite. The time difference causes the subtle differences in lighting from one side of the image to the other.

Atlantis was rolled from Orbiter Processing Facility-1 this morning to the Vehicle Assembly Building. Pictures below.

In Orbiter Processing Facility-1 at NASA’s Kennedy Space Center in Florida, workers prepare space shuttle Atlantis for its move from its hangar to transfer aisle inside the nearby Vehicle Assembly Building.

Image credit: NASA/Jack Pfaller
Oct. 6, 2009

Space shuttle Atlantis makes steady progress as it rolls toward the Vehicle Assembly Building from its hangar, Orbiter Processing Facility-1.

Image credit: NASA/Jack Pfaller
Oct. 6, 2009

After its early-morning roll from Orbiter Processing Facility-1, space shuttle Atlantis arrives in the transfer aisle of the Vehicle Assembly Building in preparation for stacking with its external fuel tank and solid rocket boosters.

Image credit: NASA/Jack Pfaller
Oct. 6, 2009

Featured image from the LROC team, details below. Remember, LCROSS’s impact is just in two days. See the sidebar for details on when exactly the event will happen.

Mare Moscoviense is a one of the many places on the lunar surface that lunar scientists want to visit. The lunar farside is quite different from the nearside; one of the bigger reasons why is that the mare basalt deposits so common on the nearside are few and far between on the farside. Since basalts form by partial melting of the lunar mantle, sampling Moscoviense basalts would provide lunar scientists with vital insights into how the lunar mantle on the farside differs from the nearside mantle, which in turn would help us to learn why mare basalts are so much rarer on the farside.

For these reasons, Moscoviense is one of the sites identified by NASA’s Project Constellation as an important site for possible future human lunar exploration. This LROC NAC image shows the view of a region several kilometers south of the proposed Exploration site, including a boundary between the mare basalts in southern Mare Moscoviense and the surrounding farside highlands. The white arrows show the location of a “bathtub ring” indicating the level that the original lavas reached as the Moscoviense basin fillled with lava. As time progressed, the erupted lavas gradually drained out of the basin, eventually solidifying at the current lower level. Human exploration of this area in particular would provide contextualized samples of the Moscoviense basalts and samples of the surrounding highlands materials, providing key and otherwise unavailable insights into the geologic history of this region.

News conference aboard ISS with all nine crew members.

Video with NASA climate scientist Tom Wagner discussing the state of Arctic sea ice in 2009.

Latest Chandra image released, which is actually combined with a Hubble image. Details below.

This image of NGC 6240 contains new X-ray data from Chandra (shown in red, orange, and yellow) that has been combined with an optical image from the Hubble Space Telescope originally released in 2008. In 2002, the discovery of two merging black holes was announced based on Chandra data in this galaxy. The two black holes are a mere 3,000 light years apart and are seen as the bright point-like sources in the middle of the image.

Scientists think these black holes are in such close proximity because they are in the midst of spiraling toward each other – a process that began about 30 million years ago. It is estimated that the two black holes will eventually drift together and merge into a larger black hole some tens or hundreds of millions of years from now.

Finding and studying merging black holes has become a very active field of research in astrophysics. Since 2002, there has been intense interest in follow-up observations of NGC 6240 by Chandra and other telescopes, as well as a search for similar systems. Understanding what happens when these exotic objects interact with one another remains an intriguing question for scientists.

The formation of multiple systems of supermassive black holes should be common in the Universe, since many galaxies undergo collisions and mergers with other galaxies, most of which contain supermassive black holes. It is thought that pairs of massive black holes can explain some of the unusual behavior seen by rapidly growing supermassive black holes, such as the distortion and bending seen in the powerful jets they produce. Also, pairs of massive black holes in the process of merging are expected to be the most powerful sources of gravitational waves in the Universe.

Shiveluch is a volcano on the Kamchatka Peninsula, in the Russian Far East. Map of where the peninsula is and more details below.

Shiveluch Volcano continued its intermittent activity on October 3, 2009. A thin plume of ash and/or steam streamed southeast from the volcano in this natural-color satellite image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra spacecraft. MODIS also detected a hotspot on the peak, implying continued growth of the lava dome in Shiveluch’s summit caldera.

White snow covers Shiveluch, Klyuchevskaya (Klyuchevskoy) to the southwest, and other nearby mountains. At lower elevations, the vegetation exhibits the brown and orange tones of fall. The southern slopes of Shiveluch are covered by gray deposits of rock and ash, the result of frequent small collapses on the flanks of the lava dome.

Shiveluch (or Sheveluch) is a stratovolcano composed of alternating layers of solidified lava, ash, and rocks from earlier eruptions. Reaching an altitude of 3,283 meters (10,771 feet) above sea level, it is one of Kamchatka’s largest and most active volcanoes. The active lava dome began growing in 1980.