NASA Embarks on Arctic Voyage to Probe Ocean, Climate Changes

NASA’s first dedicated oceanographic field campaign goes to sea next week to take an up-close look at how changing conditions in the Arctic are affecting the ocean’s chemistry and ecosystems that play a critical role in global climate change.

The ICESCAPE mission, which stands for "Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment," will investigate the impacts of climate change on the ecology and biogeochemistry of the Chukchi and Beaufort seas along Alaska's northern coast. ICESCAPE takes to sea onboard the U.S. Coast Guard Cutter Healy, the United States’ newest and most technologically advanced polar icebreaker. The Healy conducts a wide range of research activities and is designed to break four-and-a-half feet of ice continuously at three knots.

ICESCAPE takes to the sea on the U.S. Coast Guard Cutter Healy, the United States’ newest and most technologically advanced polar icebreaker. Credit: U.S. Coast Guard photo by Petty Officer Patrick Kelley

A key focus of the mission is how changes in the Arctic may be altering the ocean’s ability to absorb carbon from the atmosphere. The greenhouse gas carbon dioxide is a leading cause of global warming.

Predictions of future climate change depend on knowing the details of how this carbon cycle works in different parts of the world. NASA’s Earth science program conducts research into the global Earth system using satellite observations. Identifying how Earth's ecology and chemistry are influenced by natural processes and by humans is a key part of this research.

Declining Arctic sea ice is one factor affecting the region's changing ocean ecosystem. This image based on data from NASA's Aqua satellite shows the extent of sea ice in March 2008. Credit: NASA

The Arctic Ocean, unlike other oceans, is almost completely landlocked, making it an ideal location to study ongoing climate changes in a marine ecosystem already heavily impacted by declining sea ice cover, ocean acidification, and an increase in incoming solar radiation. These changes are likely to modify the physics, biogeochemistry, and ecology of this environment in ways that are not well understood. Satellite remote sensing has provided some insight into these changes which ICESCAPE is designed to advance.

"The ocean ecosystem in the Arctic has changed dramatically in recent years, and it’s changing much faster and much more than any other ocean in the world," said ICESCAPE chief scientist Kevin Arrigo of Stanford University. "Declining sea ice in the Arctic is certainly one reason for the change, but that’s not the whole story. We need to find out, for example, where the nutrients are coming from that feed this growth if we are going to be able to predict what the future holds for this region."

Looking southward from high over the Arctic Ocean, NASA's Aqua satellite reveals coastal phytoplankton blooms in the Chukchi Sea along northern Alaska (foreground) stretching into the Bering Strait in September 2006. Credit: NASA

The Healy leaves Dutch Harbor in Alaska's Aleutian Islands on June 15 and heads to the Bering Strait where it begins ocean sampling. The voyage continues across the southern Chukchi Sea and into the Beaufort Sea along northern Alaska’s ocean shelf. In early July the Healy will head north into deeper waters to sample thick, multi-year sea ice and take samples within and beneath the ice.

More than 40 scientists will spend five weeks at sea sampling the physical, chemical, and biological characteristics of the ocean and sea ice. A variety of instruments will be used onboard the Healy and deployed into the ocean and on the sea ice.

An automated microscope onboard will take continuous digital photographs of phytoplankton cells for near-real time observations of the quantity of different species. Floats with near-real time satellite communication will be placed in the ocean to measure temperature and various biological and optical properties. Scientists also will work on the sea ice several hundred yards from the ship to study the condition of the ice and sample the ocean ecosystem beneath it.

See how Arctic sea ice shrinks from January to September 2008
in this animation using data from NASA’s Aqua satellite.

Satellite observations are a key part of the ICESCAPE mission. NASA uses its satellite observations to monitor the microscopic plant and animal life in the world’s oceans. This "ocean color" data gives scientists a global view of a critical ecosystem that regulates the flow of carbon into and out of the sea. Similar observations of the Arctic waters collected from the Healy during ICESCAPE will be used to improve the accuracy of the satellite data over the entire region.

ICESCAPE is sponsored by the Earth Science Division’s Cryospheric Sciences and Ocean Biology and Biogeochemistry programs in NASA’s Science Mission Directorate. A second ICESCAPE voyage is planned for 2011.

For more information visit http://www.nasa.gov/topics/earth/features/icescape2010.html

Ask an Expert: Tracking Sickness From Space

Sometimes the best way to fight sickness on Earth starts with a view from space. On Thursday, June 10, Dr. Jeff Luvall, a research scientist at NASA's Marshall Space Flight Center, will answer questions about "Tracking Sickness from Space."

Joining the chat is easy. Simply visit this page on Thursday, June 10 from 3-4 p.m. EDT. The chat window will be active at the bottom of this page starting at 2:30 p.m. EDT. See you in chat!

Tracking tick habitats to help control Lyme disease is just one of many ways that NASA technology improves health on Earth. Image credit: CDC

More About Chat Expert Jeff Luvall

Dr. Jeff Luvall, a research scientist at NASA's Marshall Space Flight Center, will be answering your questions about "Tracking Sickness from Space." Luvall has been involved with tracking a variety of health-related conditions using NASA resources -- primarily satellite imagery and data and aircraft studying atmospheric and climate conditions.

A false-color electron microscope scan shows a prickly grain of prairie hollyhock pollen. Image Credit: Dartmouth College/Charles Daghlian

To date, Luvall has studied allergy-related conditions by tracking pollen, and documented and provided mitigation solutions for "urban heat islands," which occur when trapped heat builds up during the day in buildings, pavement and other urban surfaces, contributing to heat-related health issues. Additionally, Luvall has trained students and professionals to use NASA satellite data in improving medicine and contributing to public health.

One of his main areas of study for the last three years has been working with students researching Lyme and West Nile diseases. The populations of the vectors for these diseases (mosquitoes, ticks) are dependent on both habitat and environmental conditions that vary both in time and space, making them ideal to study using NASA based satellite technology.

For more information visit http://www.nasa.gov/connect/chat/sickness_from_space_chat.html

NASA's Dawn Spacecraft Fires Past Record for Speed Change

PASADENA, Calif. - Deep in the heart of the asteroid belt, on its way to the first of the belt's two most massive inhabitants, NASA's ion-propelled Dawn spacecraft has eclipsed the record for velocity change produced by a spacecraft's engines.

The previous standard-bearer for velocity change, NASA's Deep Space 1, also impelled by ion propulsion, was the first interplanetary spacecraft to use this technology. The Deep Space 1 record fell on Saturday, June 5, when the Dawn spacecraft's accumulated acceleration over the mission exceeded 4.3 kilometers per second (9,600 miles per hour).

"We are using this amazing ion-engine technology as a stepping-stone to orbit and explore two of the asteroid belt's most mysterious objects, Vesta and Ceres," said Robert Mase, Dawn project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif.

A spacecraft's change in velocity refers to its ability to change its path through space by using its own rocket engines. This measurement of change begins only after the spacecraft exits the last stage of the launch vehicle that hurled it into space.

To get to where it is in both the record books and the asteroid belt, the Dawn spacecraft had to fire its three engines - one at a time-- for a cumulative total of 620 days. In that time, it has used less than 165 kilograms (363 pounds) of xenon propellant. Over the course of its eight-plus-year mission, Dawn's three ion engines are expected to accumulate 2,000 days of operation -- 5.5 years of thrusting -- for a total change in velocity of more than 38,620 kilometers per hour (24,000 miles per hour).

NASA's Dawn spacecraft, illustrated in this artist's concept, is propelled by ion engines. Image credit: NASA/JPL

"I am delighted that it will be Dawn that surpasses DS1's record," said Marc Rayman, chief engineer for the Dawn mission and a previous project manager for Deep Space 1."It is a tribute to all those involved in the design and operations of this remarkable spacecraft."

At first glance, Dawn's pedal-to-the-metal performance is a not-so-inspiring 0-to-97 kilometers per hour (0-to-60 miles per hour) in four days. But due to its incredible efficiency, it expends only 37 ounces of xenon propellant during that time. Then take into consideration that after those four days of full-throttle thrusting, it will do another four days, and then another four. By the end of 12 days, the spacecraft will have increased its velocity by more than 290 kilometers per hour (180 miles per hour), with more days and weeks and months of continuous thrusting to come. In one year's time, Dawn's ion propulsion system can increase the spacecraft's speed by 8,850 kilometers per hour (5,500 miles per hour), while consuming the equivalent of only 16 gallons of fuel.

"This is a special moment for the spacecraft team," said Dawn's principal investigator, Chris Russell of the University of California Los Angeles. "In only 407 days, our minds will be on another set of records, the data records that Dawn will transmit when we enter Vesta orbit."

Dawn's 4.8-billion-kilometer (3-billion-mile) odyssey includes exploration of asteroid Vesta in 2011 and 2012, and the dwarf planet Ceres in 2015. These two icons of the asteroid belt have been witness to much of our solar system's history. By using the same set of instruments at two separate destinations, scientists can more accurately formulate comparisons and contrasts. Dawn's science instrument suite will measure shape, surface topography and tectonic history, elemental and mineral composition, as well as seek out water-bearing minerals. In addition, the way the Dawn spacecraft orbits both Vesta and Ceres will be used to measure the celestial bodies' masses and gravity fields.

While Dawn surpassed Deep Space 1's record for velocity change, Deep Space 1 will continue to reign as holder for the longest duration of powered spaceflight for another few months. Dawn is expected to take over that record on about August 10 of this year.

The Dawn mission to Vesta and Ceres is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. The University of California, Los Angeles, is responsible for overall Dawn mission science. Other scientific partners include Planetary Science Institute, Tucson, Ariz.; Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany; DLR Institute for Planetary Research, Berlin, Germany; Italian National Institute for Astrophysics, Rome; and the Italian Space Agency, Rome. Orbital Sciences Corporation of Dulles, Va., designed and built the Dawn spacecraft.

To learn more about Dawn and its mission to the asteroid belt, visit: http://www.nasa.gov/dawn

For more information visit http://www.nasa.gov/mission_pages/dawn/news/dawn20100607.html

Final Planned Flight of Atlantis Delivers New 'Dawn'

Space shuttle Atlantis thundered away from NASA's Kennedy Space Center on May 5, 2010 at 2:20 p.m. The on-time liftoff under a picturesque Florida sky was a perfect beginning to Atlantis' last scheduled mission, STS-132. The shuttle carried a six-person crew on a journey to deliver a new Russian module and several critical spare parts to the International Space Station.

"There are thousands of folks out there that have taken care of this bird for a long time," Commander Ken Ham said after Atlantis was cleared for launch. "We're going to take her on her 32nd flight, and if you don't mind, we'll take her out of the barn and make a few more laps around the planet."

Tucked into the shuttle's payload bay was the Russian-built Mini Research Module-1 known as "Rassvet," meaning "dawn." Nearly 20 feet long and weighing more than 17,700 pounds including its cargo, the module features eight workstations designed for a variety of science experiments and educational research.

Image above: An exhaust plume surrounds the mobile launcher platform as Atlantis launches. Image credit: NASA/Tony Gray and Tom Farrar

The ambitious tasks ahead would be taken on by a crew of experienced space fliers. Ham was joined by Pilot Tony Antonelli, Mission Specialists Garrett Reisman, Michael Good, Steve Bowen and Piers Sellers.

During the astronauts' first full day in orbit, the standard inspection of the orbiter's protective thermal coverings was completed using a backup camera system when a snagged cable temporarily prevented use of the intended laser and digital cameras. Both the primary and backup systems are part of the orbiter boom sensor system that attaches to the shuttle's robotic arm.

Atlantis docked with the International Space Station on May 16, two days after liftoff. Ham guided the orbiter through a graceful backflip known as a "rendezvous pitch maneuver," giving station crew members the chance to take nearly 400 photos of the shuttle. Finally, the two spacecraft linked up at 10:28 a.m. EDT as the pair sailed 220 miles above the South Pacific Ocean.

Image above: Anchored to the Canadarm2, Mission Specialist Garrett Reisman holds a space-to-ground antenna during the mission's first spacewalk. Image credit: NASA

The hatches between shuttle and station were opened at 12:18 p.m. and the six STS-132 astronauts were welcomed aboard by the station's six residents: cosmonauts Oleg Kotov, Expedition 23 commander, Alexander Skvortsov and Mikhail Kornienko, Japan Aerospace Exploration Agency astronaut Soichi Noguchi, and U.S. astronauts T.J. Creamer and Tracy Caldwell Dyson.

"We've been here before, but it's bigger than we remember -- and, speaking for myself, better than I remember," Ham said as docked operations officially began. "I love this place!"

The combined crew got right to work, using the station's Canadarm2 robotic arm to remove a cargo carrier from Atlantis' open payload bay to the station's mobile transporter. Mounted on the carrier were important new equipment and spares to be installed during the mission's three spacewalks, including a backup space-to-ground antenna and six 375-pound batteries.

The first of the mission's three spacewalks started the next morning at 7:54 a.m. when Reisman and Bowen switched their spacesuits to battery power and floated out of the station's Quest airlock. Riding the station's robotic arm, Reisman carried the boom for the new antenna from the cargo pallet up to the Z1 truss and returned to the cargo pallet to grab the six-foot-wide

Image above: The Russian-built Mini-Research Module 1 is removed from Atlantis' payload bay. Image credit: NASA

The pair then installed the antenna on the waiting boom, where it will help provide two-way data, voice and video communications for station residents. Reisman and Bowen added a spare-parts platform to the station's Dextre robotic arm and loosened the bolts holding the new batteries to the cargo carrier before wrapping up the 7-hour, 25-minute outing.

Installation of the Rassvet research module was the crew's next assignment. Ham and Antonelli used Atlantis' robotic arm to lift the nearly-20-foot-long component from the shuttle's payload bay, then handed it off to the station's robotic arm. Reisman guided the new module into the Earth-facing port on the Zarya module, achieving a flawless docking with one millimeter of clearance on either side of Rassvet's docking probe.

"Looks like a pretty good docking," Sellers reported to Mission Control. "Straight down the middle, got capture and contact."

Good joined Bowen for the second spacewalk, which got off to a head start at 6:38 a.m. May 19. First, Bowen fixed the snagged cable that had interfered with the early inspection of Atlantis' heat shield. After adjusting the cable and using a plastic tie to keep it in place, Mission Control announced the fix was successful.

Image above: Atlantis' belly is visible in a crystal-clear blue sky as it approaches touchdown on Runway 33. Image credit: NASA/Tony Gray and Tom Farrar

Next, the astronauts installed four of six new batteries on the station's port 6 truss, the station's backbone, transferring the old batteries to the cargo carrier for the return trip to Earth. Good and Bowen tightened the bolts on the new space-to-ground antenna before coming back inside as the 7-hour, 9-minute spacewalk ended.

Hatches between the station and Rassvet were opened the following day, as Atlantis and crew finished the mission's first week and enjoyed a few hours of off-duty time.

The final two port 6 truss batteries were installed during the mission's third and final spacewalk. Good and Reisman swapped out the remaining batteries and installed a backup ammonia coolant line between the port 4 and port 5 truss segments. They also left a new power and data grapple fixture inside the Quest airlock. The fixture will be installed by the station crew on the exterior of the Zarya module this summer.

With all the mission's major tasks accomplished, Good and Reisman headed back to the airlock after working outside the station for 6 hours and 46 minutes.

The astronauts finished transferring equipment and supplies from Atlantis to the space station as the docked portion of the STS-132 mission drew to a close.

"Thank you, Ken, and thank you to the whole crew," said station Commander Kotov as the Atlantis and station crews prepared to part ways. "Thank you for an excellent job, for your patience, for your work -- for everything."

Ham answered, "Through our entire docked timeframe here, we were a 12-person crew that operated together, and that was the only way we got everything done. ...We've had a great time together."

Image above: The STS-132 mission patch features Atlantis flying into the sunset as the end of the Space Shuttle Program approaches. However, the sun also is heralding the promise of a new day as it rises on the new ISS module, "Rassvet," the Russian word for dawn. Image credit: NASA

Atlantis undocked from the station May 23 at 11:22 a.m. after a weeklong stay at the orbiting complex. The shuttle circled the station at a distance of 400 to 600 feet and finally pulled away with a separation burn an hour and 15 minutes later.

The late inspection of Atlantis' protective skin went off without a hitch, and the shuttle was cleared to land.

Atlantis touched down at 8:48 a.m. May 26, gliding smoothly along Kennedy's Runway 33 after 186 orbits and nearly 12 full days in space. With Ham and Antonelli at the controls, the orbiter returned to its home port for what was planned to be the last time. During its 25 years of spaceflight, Atlantis completed 32 missions and traveled more than 120 million miles.

"We've all flown on Atlantis now, and some of us have flown on her a couple of times. She's a great ship," Antonelli said hours after landing, adding that it was a "real honor" to be on what may be its last flight. "We're happy to bring her back home to you here in Florida."

For more information visit http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts132/launch/132_overview.html

NASA Langley to Break Ground on Hydro Impact Basin

What goes up must come down, and it will be NASA Langley Research Center's job to make sure that when astronauts return from space, they land safely.

On June 8, NASA Langley will break ground on a $1.7 million Hydro Impact Basin that will serve to validate and certify that future space vehicles, such as NASA's Orion crew module, are designed for safe water landings.

The water basin will be 115 feet (35 m) long, 90 feet (27.4 m) wide and 20 feet (6.1 m) deep and will be built at the west end of Langley's historic Landing and Impact Research Facility, also known as the Gantry, where Neil Armstrong trained for walking on the moon. Construction will begin mid-June and will be completed by December 2010.

A series of water impact tests will be conducted using Orion drop test articles beginning in the spring of 2011. These tests will initially validate and improve the computer models of impact and acoustic loads used in the design and engineering process, and will ultimately qualify the final vehicle design for flight.

NASA Langley Research Center's Landing and Impact Research Facility will host a Hydro Impact Basin Groundbreaking ceremony Tues., June 8, 2010 in Hampton, Va.. Credit: NASA/Sean Smith

"We are excited about being a part of the nation's next space vehicle and it's landing system," said Lynn Bowman, who is managing the series of tests for the Orion project. "Our team has been involved with furthering the knowledge and testing of space vehicle landing systems and their components for the past few years."

The skill sets that NASA Langley engineers and technicians bring to the table as well as the capability of the gantry are two of the reasons the basin is being built at the center.

Bowman explains: "The Gantry provides the ability to control the orientation of the test article while imparting a vertical and horizontal impact velocity, which is required for human rating vehicles."

"This existing capability when combined with the water basin will provide a complete facility needed for landing certification of any manned spacecraft for water landing," added Bowman. "Even vehicles that do not perform a nominal water landing will need to certify for launch abort landings into water."

NASA aeronautics researchers recently dropped a small helicopter from a height of 35 feet (10.7 m) to see whether an expandable honeycomb cushion called a deployable energy absorber could lessen the destructive force of a crash. Credit: NASA/Sean Smith

Additionally, NASA Langley has more than 40 years experience with conducting controlled impact/landing tests of instrumented vehicles, said Lisa Jones, head of the Structural Testing Branch at NASA Langley.

NASA Langley's Gantry, built in 1963, was originally used to model lunar gravity. But after the Apollo program ended, it was transformed into the Impact Dynamics Research Facility and was used to test the crash worthiness of aircraft and rotorcraft.

In 2006 the Gantry experienced a revitalization as the country shifted its focus back to space exploration. The 240-foot (73 m) high Gantry provided engineers and astronauts a means to prepare for Orion's return to Earth.

When testing began in 2006, it was thought that a dry landing on Earth would be the preferred landing for the Orion capsule as it returned from space. During this phase, engineers studied the use of airbags during landings and dropped a total of 73 test articles, including a full-scale model of the Crew exploration vehicle, with different generations of airbags attached to the bottom.

More tests followed, including a series that evaluated the crew module's energy absorbing seat system, which protects the crew during a wide range of landing conditions. Langley engineers designed and built a 20,000-pound (9,072 kg) piece of steel hardware called the Crew Impact Attenuation System (CIAS) test article, which was dropped onto crushable honeycomb material sized to represent a broad range of landing conditions Orion could face.

The NASA Engineering and Safety Center recently performed a drop test of a 20,000-pound (9,072 kg) piece of steel hardware called the Crew Impact Attenuation System Test Article. The test article was dropped vertically on crushable honeycomb material. Credit: NASA/Sean Smith

In all, 117 drop tests were performed.

"This team really cranked out high quality testing and excellent analysis," said Bowman, who managed the Orion Landing System Team. "117 tests is a record."

Now that ground-landing tests are complete and the decision came to design Orion for landing in the water, the team at NASA Langley is ready to shift its focus to water. The team has already gotten its feet wet with a series of elemental water impact testing that began this past fall.

During these tests engineers dropped a 20-inch (50.8 cm) hemisphere from five feet (1.5 m) into a four-foot (1.2 m) deep pool so that they could build confidence in a design tool they might use to analyze data during the full-scale water impact tests to be done at the basin.

For more information visit http://www.nasa.gov/mission_pages/constellation/orion/hydro-impact-basin.html

Discovery's OMS Pod Removed; Crew Practices Rendezvous, Docking

Workers at NASA's Kennedy Space Center in Florida removed Discovery's right-side orbital maneuvering system pod Friday and will move it to the Hazardous Maintenance facility today for processing. The shuttle is undergoing standard launch processing for the STS-133 mission to the International Space Station.

The astronauts who will fly the mission are rehearsing in a simulator at NASA's Johnson Space Center in Houston for the rendezvous and docking at the station. The flight is targeted for launch in September.

Image above: Astronaut Tim Kopra sits in the flight engineer's position during a simulation earlier this year for the STS-133 mission. Commander Steve Lindsey is sitting in the left-hand seat in the front of the flight deck mockup as Pilot Eric Boe works in the right seat. Misison Specialist Alvin Drew is sitting beside Kopra. Image Credit: NASA

During space shuttle Discovery's final spaceflight, the STS-133 crew members will take important spares to the International Space Station along with the Express Logistics Carrier 4. Discovery is being readied for flight inside Kennedy's orbiter processing facility while its solid rocket boosters are stacked inside the nearby Vehicle Assembly Building. STS-133 is slated to launch in September.

For more information visit http://www.nasa.gov/mission_pages/shuttle/main/index.html

Next Stop, Titan: Looking at the Land o' Lakes

NASA's Cassini spacecraft will be eyeing the north polar region of Saturn's moon Titan this weekend, scanning the moon's land o' lakes.

At closest approach on early morning Saturday, June 5 UTC, which is Friday afternoon, June 4 Pacific time, Cassini will glide to within about 2,000 kilometers (1,300 miles) of the Titan surface.

Cassini will make infrared scans of the north polar region, which was in darkness for the first several years of Cassini's tour around the Saturn system. The lighting has improved as northern spring has started to dawn over the area.

Artist's concept of Cassini's June 4, 2010, flyby of Saturn's moon Titan. Image credit: NASA/JPL

The visual and infrared spectrometer will be prime during closest approach, but the imaging science subsystem cameras will also be taking pictures. Among the scientific bounties, Cassini team members are hoping to get another good look at Kraken Mare, the largest lake on Titan, which covers a greater area than the Caspian Sea on Earth.

Although this latest flyby is dubbed "T69," planning changes early in the orbital tour made this the 70th targeted flyby of Titan.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20100603.html

Lasers Help Researchers Predict Birds' Preferred Habitat

Every spring, migratory birds like the Black-throated Blue Warbler journey from tropical Caribbean or South American refuges to North American forests. But which forest patch will they call home this year? And, how can researchers predict where they choose to nest?

Ecologists studying biodiversity and conservationists preserving habitats have asked these questions for more than 50 years, but with limited and imprecise means to answer them. Now a team of NASA-funded researchers has completed an experiment to remotely sense and predict where certain birds are most likely to live and breed.

In the late 1950s, Princeton University ecologist Robert MacArthur proposed that bird species choose their habitat according to the structure of a forest – that is, the tree canopy height, branching structure, leaf spread and abundance, and the presence of low-lying shrubs.

To determine the habitat where particular species bred, ornithologists trekked deep into forests and used everything from binoculars to suspended vines to observe leaves and twigs and extrapolate the make-up of forest areas. They could spend thousands of painstaking hours analyzing plots as small as 100 square feet. As recently as May 2010, an Oregon State University doctoral student dislocated her shoulder while using a rudimentary pole to demonstrate how scientists once measured tree branches from the ground -- and to show how and why the science of studying birds has changed.

A Black-throated Blue Warbler sings from a perch in its preferred habitat of low-lying shrubery at the Hubbard Brook Experimental Forest, West Thornton, New Hampshire, in July 2007. Credit: Matt Betts/Oregon State University

"Most of the time, the data weren't very good, and didn't cover broad areas of land," said landscape ecologist Matt Betts, an assistant professor at Oregon State University in Corvallis.

A research team led by Scott Goetz of the Woods Hole Research Center in Falmouth, Mass., has helped bring habitat sensing into the 21st century. The researchers combined satellite data, a ground-based bird census, light detection and ranging (lidar), and a new modeling technique to correctly predict the presence of songbirds in a forest. Their results were published this week in the journal Ecology.

"The study of bird habitats has entered a new era," said Goetz. "Until recently, predicting bird habitat was limited. We've known for many years that the composition of trees and shrubs determines habitat quality, which in turn influences a species' presence and population density. But this study uses remote sensing to accurately predict which habitats birds prefer to use year after year, over many square miles of complex terrain."

According to Goetz, NASA's Laser Vegetation Imaging Sensor (LVIS, pronounced Elvis), was key to the team's success. The instrument sends pulses of laser light down from an airplane toward the forest canopy and records the points at which signals bounce back from leaves, branches, and land surfaces. Goetz and colleagues analyzed the data to confirm things like canopy height – the difference between the top of a tree and the ground – and the top-to-bottom density of tree canopies.

A map Goetz's team generated from a forests model indicates predicted Black-throated Blue Warbler habitat based on four years of LVIS data. Credit: Scott Goetz/Woods Hole Research Center

"We're doing the same thing our predecessors did, but in much more detail and over a much broader area," said Betts. "We have new metrics now that just weren't possible before."

When combined with data from the NASA-built Landsat satellite – which can indicate seasonal changes in the amount of vegetation -- the LVIS data indicated not only the height of the trees but whether they have mostly high branches or lots of canopy layers beneath tree tops.

The underside of tree canopies at the Hubbard Brook Experimental Forest in New Hampshire provides preferred habitat for the Black-throated Blue Warbler songbird according to both ground-based observations and Goetz's team's remotely sensed findings based on LVIS laser data. Credit: Matt Betts/Oregon State University

For the study published this month, the team made field observations of the Black-throated Blue Warbler, a small songbird that prefers lower-lying vegetation. Using four years of LVIS data, the researchers ranked various forest habitats as good, fair, or poor based on canopy structure. Their "good" rankings for the warbler matched actual ground data -- showing the actual presence of the species in each habitat -- 90 percent of the time.

"For predicting species across broad landscapes over time, this lidar technology is incredibly valuable," said Betts, a co-author of Goetz's study. "We can now conduct higher-quality estimates of the relative importance of climate versus habitat structure in affecting animal populations. And this technique should transfer to predictions of other animals whose habitats are associated with canopy structure, like flying squirrels or martens. If we can track downed logs on the forest floor, we could even model habitats for salamanders."

For more information visit http://www.nasa.gov/topics/earth/features/laser-birds.html

Hubble Images Suggest Rogue Asteroid Smacked Jupiter

Without warning, a mystery object struck Jupiter on July 19, 2009, leaving a dark bruise the size of the Pacific Ocean. The spot first caught the eye of an amateur astronomer in Australia, and soon, observatories around the world, including NASA’s Hubble Space Telescope, were zeroing in on the unexpected blemish.

Astronomers had witnessed this kind of cosmic event before. Similar scars had been left behind during the course of a week in July 1994, when more than 20 pieces of Comet P/Shoemaker-Levy 9 (SL9) plunged into Jupiter’s atmosphere. The 2009 impact occurred during the same week, 15 years later.

Astronomers who compared Hubble images of both collisions say the culprit may have been an asteroid about 1,600 feet (500 meters) wide. The images, therefore, may show for the first time the immediate aftermath of an asteroid, rather than a comet, striking another planet.

The Jupiter bombardments reveal that the solar system is a rambunctious place, where unpredictable events may occur more frequently than first thought. Jupiter impacts were expected to occur every few hundred to few thousand years. Although there are surveys to catalogue asteroids, many small bodies may still go unnoticed and show up anytime to wreak havoc.

“This solitary event caught us by surprise, and we can only see the aftermath of the impact, but fortunately we do have the 1994 Hubble observations that captured the full range of impact phenomena, including the nature of the objects from pre-impact observations” says astronomer Heidi Hammel of the Space Science Institute in Boulder, Colo., leader of the Jupiter impact study.

These NASA Hubble Space Telescope snapshots reveal an impact scar on Jupiter fading from view over several months between July 2009 and November 2009. Credit: NASA, ESA, M. Wong, H. Hammel, I. de Pater, and the Jupiter Impact Team

In 2009 Hammel’s team snapped images of the debris field with Hubble’s recently installed Wide Field Camera 3 and newly repaired Advanced Camera for Surveys.

The analysis revealed key differences between the two collisions (in 1994 and 2009), providing clues to the 2009 event. Astronomers saw a distinct halo around the 1994 impact sites in Hubble ultraviolet (UV) images, evidence of fine dust arising from a comet-fragment strike. The UV images also showed a strong contrast between impact-generated debris and Jupiter’s clouds.

Hubble ultraviolet images of the 2009 impact showed no halo and also revealed that the site’s contrast faded rapidly. Both clues suggest a lack of lightweight particles, providing circumstantial evidence for an impact by a solid asteroid rather than a dusty comet.

The elongated shape of the recent impact site also differs from the 1994 strike, indicating that the 2009 object descended from a shallower angle than the SL9 fragments. The 2009 body also came from a different direction than the SL9 pieces.

Team member Agustín Sanchez-Lavéga of the University of the Basque Country in Bilbao, Spain, and colleagues performed an analysis of possible orbits that the 2009 impacting body could have taken to collide with Jupiter. Their work indicates the object probably came from the Hilda family of bodies, a secondary asteroid belt consisting of more than 1,100 asteroids orbiting near Jupiter.

The 2009 strike was equal to a few thousand standard nuclear bombs exploding, comparable to the blasts from the medium-sized fragments of SL9. The largest of those fragments created explosions that were many times more powerful than the world’s entire nuclear arsenal blowing up at once.

The recent impact underscores the important work performed by amateur astronomers. “This event beautifully illustrates how amateur and professional astronomers can work together,” notes Hammel.

Occasional dark spots have appeared on Jupiter throughout the history of sky watching. Observing records of the planet are filled with references to spots, including “white spots,” “peculiar spots,” and “well-defined spots.” Only a handful may have described possible Jupiter strikes.

In 1686, the Italian astronomer Giovanni Cassini reported a dark spot on Jupiter that was roughly the size of the largest SL9 impact. Nearly 150 years later, in 1834, British astronomer George Airy independently reported a dark feature in Jupiter’s southern belts that looked nearly four times as large as shadows cast on the planet by the Galilean moons. Crude telescopes prevented sky watchers from probing the nature of those spots.

The study by Hammel’s team appeared in the June 1 issue of The Astrophysical Journal Letters.

For images and more information about Jupiter, visit:
hubblesite.org/news/2010/16
nasa.gov/hubble

For more information visit http://www.nasa.gov/mission_pages/hubble/science/jupiter-strike.html

What is Consuming Hydrogen and Acetylene on Titan?

PASADENA, Calif. - Two new papers based on data from NASA's Cassini spacecraft scrutinize the complex chemical activity on the surface of Saturn's moon Titan. While non-biological chemistry offers one possible explanation, some scientists believe these chemical signatures bolster the argument for a primitive, exotic form of life or precursor to life on Titan's surface. According to one theory put forth by astrobiologists, the signatures fulfill two important conditions necessary for a hypothesized "methane-based life."

One key finding comes from a paper online now in the journal Icarus that shows hydrogen molecules flowing down through Titan's atmosphere and disappearing at the surface. Another paper online now in the Journal of Geophysical Research maps hydrocarbons on the Titan surface and finds a lack of acetylene.

This lack of acetylene is important because that chemical would likely be the best energy source for a methane-based life on Titan, said Chris McKay, an astrobiologist at NASA Ames Research Center, Moffett Field, Calif., who proposed a set of conditions necessary for this kind of methane-based life on Titan in 2005. One interpretation of the acetylene data is that the hydrocarbon is being consumed as food. But McKay said the flow of hydrogen is even more critical because all of their proposed mechanisms involved the consumption of hydrogen.

"We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth," McKay said. "If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."

This artist concept shows a mirror-smooth lake on the surface of the smoggy moon Titan. Image credit: NASA/JPL

To date, methane-based life forms are only hypothetical. Scientists have not yet detected this form of life anywhere, though there are liquid-water-based microbes on Earth that thrive on methane or produce it as a waste product. On Titan, where temperatures are around 90 Kelvin (minus 290 degrees Fahrenheit), a methane-based organism would have to use a substance that is liquid as its medium for living processes, but not water itself. Water is frozen solid on Titan's surface and much too cold to support life as we know it.

The list of liquid candidates is very short: liquid methane and related molecules like ethane. While liquid water is widely regarded as necessary for life, there has been extensive speculation published in the scientific literature that this is not a strict requirement.

The new hydrogen findings are consistent with conditions that could produce an exotic, methane-based life form, but do not definitively prove its existence, said Darrell Strobel, a Cassini interdisciplinary scientist based at Johns Hopkins University in Baltimore, Md., who authored the paper on hydrogen.

Strobel, who studies the upper atmospheres of Saturn and Titan, analyzed data from Cassini's composite infrared spectrometer and ion and neutral mass spectrometer in his new paper. The paper describes densities of hydrogen in different parts of the atmosphere and the surface. Previous models had predicted that hydrogen molecules, a byproduct of ultraviolet sunlight breaking apart acetylene and methane molecules in the upper atmosphere, should be distributed fairly evenly throughout the atmospheric layers.

Strobel found a disparity in the hydrogen densities that lead to a flow down to the surface at a rate of about 10,000 trillion trillion hydrogen molecules per second. This is about the same rate at which the molecules escape out of the upper atmosphere.

"It's as if you have a hose and you're squirting hydrogen onto the ground, but it's disappearing," Strobel said. "I didn't expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape."

Strobel said it is not likely that hydrogen is being stored in a cave or underground space on Titan. The Titan surface is also so cold that a chemical process that involved a catalyst would be needed to convert hydrogen molecules and acetylene back to methane, even though overall there would be a net release of energy. The energy barrier could be overcome if there were an unknown mineral acting as the catalyst on Titan's surface.

The hydrocarbon mapping research, led by Roger Clark, a Cassini team scientist based at the U.S. Geological Survey in Denver, examines data from Cassini's visual and infrared mapping spectrometer. Scientists had expected the sun's interactions with chemicals in the atmosphere to produce acetylene that falls down to coat the Titan surface. But Cassini detected no acetylene on the surface.

In addition Cassini's spectrometer detected an absence of water ice on the Titan surface, but loads of benzene and another material, which appears to be an organic compound that scientists have not yet been able to identify. The findings lead scientists to believe that the organic compounds are shellacking over the water ice that makes up Titan's bedrock with a film of hydrocarbons at least a few millimeters to centimeters thick, but possibly much deeper in some places. The ice remains covered up even as liquid methane and ethane flow all over Titan's surface and fill up lakes and seas much as liquid water does on Earth.

"Titan's atmospheric chemistry is cranking out organic compounds that rain down on the surface so fast that even as streams of liquid methane and ethane at the surface wash the organics off, the ice gets quickly covered again," Clark said. "All that implies Titan is a dynamic place where organic chemistry is happening now."

The absence of detectable acetylene on the Titan surface can very well have a non-biological explanation, said Mark Allen, principal investigator with the NASA Astrobiology Institute Titan team. Allen is based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Allen said one possibility is that sunlight or cosmic rays are transforming the acetylene in icy aerosols in the atmosphere into more complex molecules that would fall to the ground with no acetylene signature.

"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed," Allen said. "We have a lot of work to do to rule out possible non-biological explanations. It is more likely that a chemical process, without biology, can explain these results - for example, reactions involving mineral catalysts."

"These new results are surprising and exciting," said Linda Spilker, Cassini project scientist at JPL. "Cassini has many more flybys of Titan that might help us sort out just what is happening at the surface."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

For more information about the Cassini-Huygens mission visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

For more information visit http://www.nasa.gov/topics/solarsystem/features/titan20100603.html

NASA Rover Finds Clue to Mars' Past And Environment for Life

PASADENA, Calif. -- Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA's rovers have found other evidence of formerly wet Martian environments. However the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Lengthy detective work with data NASA's Mars Exploration Rover Spirit collected in late 2005 has confirmed that an outcrop called "Comanche" contains a mineral indicating that a past environment was wet and non-acidic, possibly favorable to life. Image credit: NASA/JPL-Caltech/Cornell University

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place. "

Spirit inspected rock outcrops, including one scientists called Comanche, along the rover's route from the top of Husband Hill to the vicinity of the Home Plate plateau which Spirit has studied since 2006. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

"We used detective work combining results from three spectrometers to lock this down," said Dick Morris, lead author of the report and a member of a rover science team at NASA's Johnson Space Center in Houston."The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is."

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.

It is important to determine where most of the carbon dioxide went. Some theorize it departed to space. Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Morris suspected iron-bearing carbonate at Comanche years ago from inspection of the rock with Spirit's Moessbauer Spectrometer, which provides information about iron-containing minerals. Confirming evidence from other instruments emerged slowly. The instrument with the best capability for detecting carbonates, the Miniature Thermal Emission Spectrometer, had its mirror contaminated with dust earlier in 2005, during a wind event that also cleaned Spirit's solar panels.

NASA's Mars Rover Spirit began its Mars exploration at its landing site in January 2004. Image credit: NASA/JPL-Caltech/UA/Cornell/NM Museum of Natural History and Science

"It was like looking through dirty glasses," said Steve Ruff of Arizona State University in Tempe, Ariz., another co-author of the report. "We could tell there was something very different about Comanche compared with other outcrops we had seen, but we couldn't tell what it was until we developed a correction method to account for the dust on the mirror."

Spirit's Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The rovers landed on Mars in January 2004 for missions originally planned to last three months. Spirit has been out of communication since March 22 and is in a low-power hibernation status during Martian winter. Opportunity is making steady progress toward a large crater, Endeavour, which is about seven miles away.

NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Exploration Rovers for the agency's Science Mission Directorate in Washington. For more information about the rovers, visit:

http://www.nasa.gov/rovers

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20100603.html

NASA Center for Climate Simulation: Data Supporting Science

Debuting in spring 2010, the NASA Center for Climate Simulation (NCCS) is the new name for a Goddard Space Flight Center organization that has provided supercomputing resources to NASA scientists and engineers for over 25 years.

"Computation here at Goddard is primarily to create datasets and make them available for science researchers around the world," said Phil Webster, chief of Goddard's Computational and Information Sciences and Technology Office, which includes NCCS. With climate and weather modeling representing the bulk of NCCS computing, the new name reflects "our mission to support NASA Earth science."

Supercomputing the Climate

This short video introduces the NCCS and takes you behind-the-scenes into the fascinating field of climate modeling. Credit: NASA/Goddard Space Flight Center

› Download this video from Goddard's Scientific Visualization Studio

This science is carried out by hundreds of NCCS users from Goddard, other NASA centers, laboratories, and universities across the U.S. The two largest user groups are Goddard's Global Modeling and Assimilation Office (GMAO), headed by Michele Rienecker, and the Goddard Institute for Space Studies (GISS), directed by Jim Hansen. NCCS-hosted simulations span time scales from days (weather prediction) to seasons and years (short-term climate prediction) to decades and centuries (climate change projection).

Data-Centric Science

At any time scale, NASA climate simulations use and produce vast amounts of data. "The unique thing about NASA is that we are the source of most of the research satellite observational data of the atmosphere, land, and ocean," Webster said. Add data from the National Oceanic and Atmospheric Administration (NOAA) and other sources, and GMAO needs to process as many as 8 million observations from satellites and additional platforms per day before assimilating them into models.

The NASA Center for Climate Simulation (NCCS) Data Exploration Theater features a 17- by 6-foot multi-screen visualization wall for engaging visitors and scientists with high-definition movies of simulation results. Here, the wall displays a 3.5-kilometer-resolution global simulation that captures numerous cloud types at groundbreaking fidelity. Credit: NASA/Goddard/Pat Izzo

Data assimilation and other techniques create the right starting conditions for simulating physical processes around the Earth. In predicting future conditions, climate models generate data much like the observations: temperature, humidity, wind speed and direction, precipitation, and other values. Data processing requirements can be considerable. The largest project run at NCCS to date -- GMAO's Modern Era Retrospective-analysis for Research and Applications (MERRA) -- ingests more than 50 billion observations over the Earth Observing System satellite era. MERRA will eventually produce more than 150 terabytes (tera = trillion) of value-added Earth science data.

Today's climate science is "data-centric," as Webster describes it. "Everything we do supports the creation, utilization, and exploitation of Earth science model data," he said. The new NCCS is expanding its services to meet NASA's growing climate data needs.

Augmented Supercomputer

The heart of the new NCCS is the "Discover" supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. The new processors are from Intel's latest Xeon 5500 series, which uses the Nehalem architecture introduced in spring 2009. Nehalem is well suited to climate studies, offering greater speed, larger memory, and faster memory access than processors installed just one year before. Significant augmentations to Discover will occur in summer 2010.

"With the new augmentations of Discover we probably have a 3 to 4x increase in the amount of work that we can push through the computer in a day," Webster said. "You can run more simulations at the same resolutions you've had, but the thing that really excites us is that we can run much higher resolution simulations."

The heart of NCCS is the “Discover” supercomputer. In 2009, NCCS added more than 8,000 computer processors to Discover, for a total of nearly 15,000 processors. Discover-hosted simulations span time scales from days (weather prediction) to seasons and years (short-term climate prediction) to decades and centuries (climate change projection). Credit: NASA/Pat Izzo

Using Discover's new Nehalem processors, a "cubed-sphere" version of GMAO's flagship Goddard Earth Observing System Model, Version 5 (GEOS-5) ran at resolutions including 3.5 kilometers -- equaling the highest resolution to date for a global climate model. Most startling is the formation of numerous cloud types at groundbreaking fidelity. "When you hold that up against pictures taken from satellites, it's almost impossible to tell the difference between the simulation and the pictures," Webster said.

Working with Data

In addition to powerful computers, NCCS has long had a massive data archive for researchers to store, and later retrieve, model output and other data. The archive's current capacity is 17.5 petabytes (peta = 1,000 trillion). A new data management system (DMS) will reduce dataset duplication and keep the most heavily used datasets online for faster access. DMS software tools will help users to more easily locate and access the data they need.

NCCS is also expanding its data analysis and visualization capabilities. Webster explained that it is very difficult to analyze terabytes of data on a standard workstation, which might have a few hundred gigabytes of disk and perhaps eight gigabytes of memory. The NCCS' "Dali" analysis system offers "a machine comparable to the size of the data that is being generated by the computing center," Webster said. It is "specifically designed to allow a scientist to use that data as quickly as possible." Dali's capabilities include data visualization, scientific workflow management, and diagnostics for model evaluation and comparison. For visualization at room size, a 17- by 6-foot multi-screen visualization wall is engaging visitors and scientists with high-definition movies of simulation results.

Over the last few years, NCCS has distributed simulation data to users and non-users alike through its Data Portal. Especially to support data distribution for NASA's Intergovernmental Panel on Climate Change (IPCC) simulations, NCCS is deploying a node on the Earth System Grid (ESG). ESG integrates supercomputers with large-scale data and analysis servers at national laboratories and research centers, with the goal of "turning climate datasets into community resources."

The Modern Era Retrospective-analysis for Research and Applications (MERRA) is producing a comprehensive record of Earth’s weather and climate from 1979, the beginning of the operational Earth observing satellite era, up to the present. This visualization depicts specific atmospheric humidity on June 17, 1993, during the Great Flood that hit the Midwestern United States. Credit: Research: Michele Rienecker, Max Suarez, Ron Gelaro, Julio Bacmeister, Ricardo Todling, Larry Takacs, Emily Liu, Steve Pawson, Mike Bosilovich, Siegfried Schubert, Gi-Kong Kim, NASA/Goddard; Visualization: Trent Schindler, NASA/Goddard/UMBC

The IPCC's Fifth Assessment Report, due to be completed in 2014, will include input from climate modeling groups worldwide. NASA contributions will come from GISS and GMAO, which are running the latest versions of their models on Discover. GISS ModelE will perform simulations going back a full millennium and forward to 2100. GMAO will focus on the years 1960 to 2035 and perform decadal prediction simulations using GEOS-5 and atmospheric chemistry-climate simulations using the GEOS Chemistry Climate Model. Employing ESG and its common data format, NCCS expects to distribute more than 50 terabytes of data from IPCC simulations to the climate research community.

Within that community, Webster sees Goddard and NCCS as particularly equipped to make contributions. "We have a tremendous amount of observational data, which is captured by our satellites," he said. "We have probably the largest collection of Earth scientists anywhere in the world, and we have this new state-of-the-art computing center. The combination of the data, the scientists, and the computing puts us in a unique position to enable advances in weather and climate research."

Related Links

NASA Center for Climate Simulation – http://www.nccs.nasa.gov/

Global Modeling and Assimilation Office – http://gmao.gsfc.nasa.gov/

Goddard Institute for Space Studies – http://www.giss.nasa.gov/

NASA High-End Computing Program – http://www.hec.nasa.gov/

Multimedia Resources – http://svs.gsfc.nasa.gov/Gallery/NCCS.html

For more information visit http://www.nasa.gov/topics/earth/features/climate-sim-center.html

Tropical Cyclone Phet Intensifies, Coastal Oman Bracing for Strong Winds, Heavy Rains

Tropical storm Phet intensified over the last 24 hours and has grown into a full-blown and powerful cyclone. NASA's Terra satellite imagery of the storm from earlier today also revealed an eye in the storm, confirming the intensification. Residents of coastal Oman are bracing for strong winds, heavy rainfall and rough surf today and tomorrow.

NASA's Terra satellite flew over Tropical Cyclone Phet at 06:55 UTC (2:55 a.m. EDT or 6:55 p.m. local time/Pakistan). The Moderate Resolution Imaging Spectroradiometer instrument, or MODIS captured a visible image of Phet at that time, and noticed an eye in the center of the storm's circulation. Satellite imagery indicates the eye is about 12 kilometers (7 miles) in diameter.

NASA's MODIS instrument captured a visible image of Phet at 06:55 UTC (2:55 a.m. EDT or 6:55 p.m. local time/Pakistan) on June 2, and indicated the eye is about 12 kilometers (7 miles) in diameter. Credit: NASA Goddard/ MODIS Rapid Response Team

At 0900 UTC (9 p.m. local time/Pakistan), Tropical Cyclone Phet had maximum sustained winds near 110 knots (126 mph) with gusts to 135 knots (155 mph). It is now considered a major cyclone (equivalent to a Category 3 hurricane on the Saffir-Simpson hurricane scale). It is about 560 miles southwest of Karachi, Pakistan, near 17.7 North and 60.6 East. It is moving to the northwest near 5 knots (6 mph). Cyclone-force winds extend to 35 miles from the storm's center, while tropical-storm force winds extend as far as 75 miles from the center. It is creating very rough seas on the Arabian Sea with waves as high as 18 feet.

Cyclone Phet is a threat to coastal Oman, India (Gujarat), and Pakistan (Sindh and Balochistan). The Joint Typhoon Warning Center (JTWC) has forecast the storm to continue intensifying and to approach Oman on its way to a weekend landfall in southeastern Pakistan between Karachi and to the border with India.

RSMC New Delhi warns that gale force winds will be experienced along the Oman coast today and tomorrow as Phet continues to move through the Arabian Sea.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_phet.html

Backwards Black Holes Might Make Bigger Jets

PASADENA, Calif. - Going against the grain may turn out to be a powerful move for black holes. New research suggests supermassive black holes that spin backwards might produce more ferocious jets of gas. The results have broad implications for how galaxies change over time.

"A lot of what happens in an entire galaxy depends on what's going on in the miniscule central region where the black hole lies," said theoretical astrophysicist David Garofalo of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Garofalo is lead author of a new paper that appeared online May 27 in the Monthly Notices of the Royal Astronomical Society. Other authors are Daniel A. Evans of the Massachusetts Institute of Technology, Cambridge, Mass., and Rita M. Sambruna of NASA Goddard Space Flight Center, Greenbelt, Md.

Black holes are immense distortions of space and time with gravity that is so great, even light itself cannot escape. Astronomers have known for more than a decade that all galaxies, including our own Milky Way, are anchored by tremendous, so-called supermassive black holes, containing billions of suns' worth of mass. The black holes are surrounded and nourished by disks of gas and dust, called accretion disks. Powerful jets stream out from below and above the disks like lasers, and fierce winds blow off from the disks themselves.

The black holes can spin either in the same direction as the disks, called prograde black holes, or against the flow - the retrograde black holes. For decades, astronomers thought that the faster the spin of the black hole, the more powerful the jet. But there were problems with this "spin paradigm" model. For example, some prograde black holes had been found with no jets.

Garofalo and his colleagues have been busy flipping the model on its head. In previous papers, they proposed that the backward, or retrograde, black holes spew the most powerful jets, while the prograde black holes have weaker or no jets.

This artist's concept shows a galaxy with a supermassive black hole at its core. The black hole is shooting out jets of radio waves. Image credit: NASA/JPL-Caltech

The new study links the researchers' theory with observations of galaxies across time, or at varying distances from Earth. They looked at both "radio-loud" galaxies with jets, and "radio-quiet" ones with weak or no jets. The term "radio" comes from the fact that these particular jets shoot out beams of light mostly in the form of radio waves.

The results showed that more distant radio-loud galaxies are powered by retrograde black holes, while relatively closer radio-quiet objects have prograde black holes. According to the team, the supermassive black holes evolve over time from a retrograde to a prograde state.

"This new model also solves a paradox in the old spin paradigm," said David Meier, a theoretical astrophysicist at JPL not involved in the study. "Everything now fits nicely into place."

The scientists say that the backward black holes shoot more powerful jets because there's more space between the black hole and the inner edge of the orbiting disk. This gap provides more room for the build-up of magnetic fields, which fuel the jets, an idea known as the Reynold's conjecture after the theoretical astrophysicist Chris Reynolds of the University of Maryland, College Park.

"If you picture yourself trying to get closer to a fan, you can imagine that moving in the same rotational direction as the fan would make things easier," said Garofalo. "The same principle applies to these black holes. The material orbiting around them in a disk will get closer to the ones that are spinning in the same direction versus the ones spinning the opposite way."

Jets and winds play key roles in shaping the fate of galaxies. Some research shows that jets can slow and even prevent the formation of stars not just in a host galaxy itself, but also in other nearby galaxies.

"Jets transport huge amounts of energy to the outskirts of galaxies, displace large volumes of the intergalactic gas, and act as feedback agents between the galaxy's very center and the large-scale environment," said Sambruna. "Understanding their origin is of paramount interest in modern astrophysics."

The California Institute of Technology, Pasadena, manages JPL for NASA.

For more information visit http://www.nasa.gov/topics/universe/features/spitzer20100601.html

Hurricane Season 2010: Tropical Storm Phet (Northern Indian Ocean)

Tropical Cyclone Phet Threatens the Indian and Pakistani Coastlines

NASA satellite imagery confirmed that Tropical cyclone 03A has intensified quickly in the last 24 hours, and as a result, the storm has been renamed Tropical Storm Phet. Phet is located in the Arabian Sea, Northern Indian Ocean, and is threatening the Indian and Pakistani coastlines.

NASA's Aqua satellite flew over Tropical Storm Phet on June 1 at 9:11 UTC (5:11 EDT) and captured an infrared image of the cloud top temperatures. The image indicated large areas of high, cold cloud tops, as cold as -63 degrees Fahrenheit, indicating strong convection.

At 1500 UTC (11 a.m. EDT) on June 1, Tropical Storm Phet had maximum sustained winds near 55 knots (62 mph) with higher gusts. Phet was located about 550 miles south-southwest of Karachi, Pakistan, near 16.8 North and 62.2 East. Phet is moving to the northwest near 6 knots (7 mph).

NASA's Aqua satellite flew over Tropical Storm Phet on June 1 at 9:11 UTC (5:11 EDT) and captured this infrared image of the cloud top temperatures. The purple color indicates high, cold cloud tops, as cold as -63 degrees Fahrenheit, indicating strong convection. Credit: NASA JPL, Ed Olsen

Current landmasses threatened by Phet include: India (Gujarat), Pakistan (Sindh and Balochistan).

Phet is forecast to continue strengthening and turn northeast later this week. The Joint Typhoon Warning Center forecasts landfall by the end of the week in the border area between India and Pakistan.

Regional warnings are already in effect for the Indian and Pakistani coastlines from Thursday on. The Indian Meteorological Department's Regional Specialized Meteorological Center noted on June 1, "Under the influence of this system, fairly widespread rainfall with isolated heavy to very heavy falls would commence over coastal areas of Gujarat from June 3 and increase thereafter. Squally winds with speed reaching 55-65 kmph (34-40 mph) (with higher gusts) would commence along and off Gujarat coast from June 2 and increase gradually." For updated forecasts, visit: www.imd.gov.in

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_phet.html