Astronomers at NASA's Marshall Space Flight Center have recorded the br
ightest meteor seen by their network in almost three years of operation. On May 20, 2011, at 9:47 p.m. CDT, a six-foot diameter fragment of an unknown comet entered the atmosphere approximately 66 miles above the city of Macon, Ga., traveling northwest at a speed of some 24 miles per second (86,000 mph). At this velocity, the boulder-sized "dirty snowball" possessed an energy or striking power somewhere between 500-1000 tons of TNT.This was seen by many eyewitnesses in Georgia and Alabama; the American Meteor Society has some of the reports here: 
It was tracked by two NASA all sky cameras, one located in Chickamauga, Ga., and the other at the Tellus Science Museum in the town of Cartersville, Ga. Analysis of the video data from these cameras enabled the Meteoroid Environment Office to estimate the trajectory, speed, mass and orbit of the meteor. More information on these cameras and a log of recent meteor events can be found at: http://fireballs.ndc.nasa.gov.Fortunately the atmosphere provided us with excellent protection, as the 
video below illustrates. Because the video is slowed to one-third of the actual real-time speed, it's easy to spot the large fragments coming off in the wake after the flares.The video shows four distinct flares caused by the meteor breaking apart in its fiery final few seconds. You can see fragments coming off in the meteor's wake after three of these flares. After a last burst of light, the meteor ablated -- or "burned up" -- 38 miles above the town of Villa Rica, Ga., located on the border between Carrol and Douglas counties in Georgia.
On Wednesday, April 27, a widespread and historic severe weather outbreak occurred across the southeastern United States, including numerous, significant, and long-track tornadoes across the state of Alabama, causing billions in state-wide damage. NASA's Short-term Prediction Research and Transition (SPoRT) Center at Marshall Space Flight Center in Huntsville, Ala. is helping in the aftermath of these severe storms by providing the National Weather Service (NWS) with unique NASA satellite data for observation and damage assessment.
On May 19 from 3-4 p.m. EDT, members of the NASA SPoRT team will answer questions on these topics, to discuss how NASA is involved in weather forecasting research and their support of National Weather Service activities. Research meteorologists Andrew Molthan and Brad Zavodsky will be joined by Applications Integration Meteorologist Brian Carcione of the National Weather Service Forecast office in Huntsville, Alabama and available to answer your questions, to learn more about SPoRT and NASA's activities in support of local severe weather prediction and response.
Joining the chat is easy! Simply return to this page http://www.nasa.gov/connect/chat/sport_chat.html a few minutes before the chat begins. The chat module will appear at the bottom of this page. After you log in, wait for the chat module to be activated, then ask your questions!More About SPoRTThe SPoRT Center assists with damage assessments through application of high resolution imagery obtained from NASA polar-orbiting satellites, such as Terra and Aqua. SPoRT is using these capabilities and data sets to assist the NWS in the severe storms that occurred in the Tennessee Valley, such as the recent historic April 27 outbreak.
During severe weather, the SPoRT Center provides total lightning data to forecasters via the North Alabama Lightning Mapping Array, useful for monitoring storm severity and potentially increasing lead time for hail, wind, and tornadoes. The SPoRT Center provides training and support to the NWS in the use of total lightning data to aid in the prediction of short-term severe weather events.The SPoRT Center continues to investigate new data sets and data assimilation techniques to improve weather predictive capabilities using high resolution weather forecast models. Improved forecast models increase the awareness of severe weather likelihood, providing additional lead time for public advisories and other preparedness activities.
Recent Landsat satellite data captured by the USGS and NASA on May 10 shows the major flooding of the Mississippi River around Memphis, Tenn. and along the state borders of Tennessee, Kentucky, Missouri, and Arkansas as seen from 438 miles above the Earth.The flood crest of 47.87 feet on May 10, is the second highest rise in recent history; the highest being 48.7 feet in 1937. Five counties surrounding Memphis have been declared disaster areas, and the costs of the flooding are expected to approach $1 billion. The Mississippi River crest continues to move south and is expected to occur in the Greenville, Miss. Area around May 16 to finally crest in New Orleans around May 23.When natural hazards like flooding occur, USGS provides the most recent Landsat data to local emergency managers."Landsat imagery is crucial in helping to monitor the flood rate and effects of the flooding in the region, and to aid in the decision making process regarding flood control. Decisions such as closing portions of the Mississippi River to shipping and opening flood gates outside of low-lying New Orleans in preparation to the flood wave as it makes its way slowly down the river to the Gulf of Mexico," said Mark Anderson, Acting Director of the USGS Earth Resources Observation and Science Center.
James Irons, Landsat Data Continuity Mission (LDCM) Project Scientist at NASA Goddard Space Flight Center in Greenbelt, Md. said, "NASA Goddard has managed the development of all the successfully launched Landsat satellites and is currently developing the next Landsat satellite system, the Landsat Data Continuity Mission, in partnership with USGS." The launch of LDCM is scheduled for December, 2012.Remotely sensed data are not the only science endeavors occurring due to floods. The USGS collects river data through its network of about 7,700 stream gauges around the Nation. You can receive instant, customized updates about water conditions, including flooding, by subscribing to USGS WaterAlert.The scenes captured by Landsat 5 show the Mississippi River in the Memphis, Tenn. area, and along the state borders of Tennessee, Kentucky, Missouri, and Arkansas. The January images show the river before it began to flood. In the May images, the dark blue tones are water, the light green is cleared fields, and the light tones are clouds.
Design techniques honed at NASA's Jet Propulsion Laboratory in Pasadena, Calif., for Mars rovers were used to create the rover currently examining the inside of Japan's nuclear reactors, in areas not yet deemed safe for human crews.
The iRobot PackBot employs technologies used previously in the design of "Rocky-7," which served as a terrestrial test bed at JPL for the current twin Mars rovers, Spirit and Opportunity. PackBot's structural features are modeled after Rocky-7, including the lightweight, high-torque actuators that control the rover; and its strong, lightweight frame structure and sheet-metal chassis.PackBot's other "ancestor," called Urbie, was an urban reconnaissance robot with military and disaster response applications. Urbie's lightweight structure and rugged features also made it useful in emergency response situations; for example, at sites contaminated with radiation and chemical spills, and at buildings damaged by earthquakes. Urbie's physical structure was designed by iRobot Corp., Bedford, Mass., while JPL was responsible for the intelligent robot's onboard sensors and vision algorithms, which helped the robot factor in obstacles and determine an appropriate driving path. Following the success of Urbie's milestones, the team at iRobot created its successor: PackBot.Since 2002, iRobot has delivered variations of the PackBot model to the U.S. Army, U.S. Air Force and U.S. Navy. The tactical robot's first military deployment was to Afghanistan in July 2002, to assist soldiers by providing "eyes and ears" in the most dangerous or inaccessible areas. It was also used to search through debris at Ground Zero after the Sept. 11, 2001 attacks in New York.Recently, iRobot provided two PackBots to help after the devastating March 11
, 2011, earthquake and tsunami in Japan. The PackBot models, currently taking radioactivity readings in the damaged Fukushima Daiichi nuclear power plant buildings, are equipped with multiple cameras and hazard material sensors. The images and readings provided by the PackBots indicated radiation levels are still too high to allow human repair crews to safely enter the buildings.Urbie was a joint effort of the Defense Advanced Research Project's Agency's (DARPA) Tactical Mobile Robot program, JPL, iRobot Corp., the Robotics Institute of Carnegie Mellon University, and the University of Southern California's Robotics Research Laboratory. JPL is managed for NASA by the California Institute of Technology in Pasadena.
Tornado tracks from last week's powerful tornado outbreak are visible in data from NASA's Aqua satellite and the Landsat satellite.Among the more than 150 tornadoes reported on April 27 and 28, 2011, was a rare EF-5 storm. Such a storm has the capacity to collapse a concrete building. The tornado hit Smithville, Mississippi, where it killed at least 14 people, and moved northeast nearly 3 miles toward the Alabama border. It is the first EF5 tornado to occur in Mississippi since 1966, according to the National Weather Service.An image captured by NASA's Aqua satellite shows the path of exposed ground left in the tornado’s wake. The trail left by the EF5 tornado in Mississippi is much shorter than a similar trail that cuts across northwestern Alabama. The National Weather Service rated this tornado at EF4, with winds around 175 miles per hour, said local news reports. The track was about 12 miles long, and the tornado caused more than 20 deaths.
The image was taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 28. The image was compared to an earlier image taken on April 12, 2011 and the tracks were not present.The tornado of April 27, 2011 hit Smithville, Mississippi, where it killed at least 14 people, and moved northeast nearly 3 miles toward the Alabama border. This NASA MODIS image shows the path of exposed ground left in the tornado’s wake. The trail left by the EF5 tornado in Mississippi is much shorter than a similar trail that cuts across northwestern Alabama. Credit: NASA MODIS Rapid Response Team, Jeff SchmaltzAnother satellite revealed the track from a tornado that touched down near Griffin, Georgia. In a Landsat image from April 28, 2011, a pale green swath indicated the path of a tornado outside of Griffin, Georgia. The tornado was on the ground between 12:03 and 12:28 a.m. local time on April 28, hours before the image was taken. By the time the funnel cloud lifted, the tornado had covered about 20 miles with a path about half a mile wide, said the National Weather Service. The tornado was an EF3 tornado with winds of about 140 miles per hour.The Landsat satellite image showed that the tornado moved across lightly populated farmland. Bright-colored spots that appear in the image are buildings, and some were close to storm’s path. The town of Griffin is the nearest community to the storm track in this area. Landsat data was provided by the United States Geological Survey.
The space shuttle is the undisputed star of launch day, with its towering fire and thunderous sound as it soars into the heavens. It gets significant help, though, from a robust supporting actor in the form of a gray launch pad and its weave of wiring, pipes and even a crane.
The pad area is a rough circle more than a mile-and-a-half around. Inside that circle lie huge propellant tanks, banks of high-speed and television cameras, and a water tower that deluges the pad just before liftoff. Baskets anchored beneath high-tension cables stand ready to evacuate astronauts from a shuttle to a protective bunker. The shuttle stack stands in the middle of it all, the ultimate focus of human and hardware attention.All at a place less than a mile from the ocean that broils in the Florida summer and chills in the winter. As with so many places at NASA's Kennedy Space Center, it's a unique world to work in."I kind of feel like I found home," said Kevin Panik, NASA's Pad Facility Integration manager. "I come to work and it's not work. I'm driving in and I'm smiling."David Sutherland, Pad Operations manager for United Space Alliance, started working at the shuttle launch pads in 1987."I'm a lucky guy, no doubt about it," Sutherland said. "I never in my wildest dreams thought I'd have a job like this. Not just being an engineer on shuttle, but being manager of operations. Pretty lucky guy."Sutherland saw the pad the first time during a job interview.
"I just couldn't imagine that it was this big," he recalled. "It just looked so complicated, that there was so much to it that I'd never understand it, never get it."About 170 engineers and technicians work at the launch pad to ready a shuttle for liftoff, along with a few dozen more specialists who come and go during the 30-day preparation period at the pad. Those preparations range from the broad tasks of connecting hundreds of wires and cables when the shuttle stack rolls to the pad to the delicate work of moving multi-ton payloads inches at a time into the cargo bay."You can't know it all," Panik said. "There's some 50, 75 different systems. You've got to realize you can't know it all."The crews who work on the launch pad are affectionately called "pad rats" and they average between 16 and 17 years of experience, Sutherland said. Their specialties rang
e from handling extremely toxic chemicals to tying down metal platforms, rails and equipment with rope to prevent it from accidentally impacting the spacecraft. The team also is cross-trained in a number of specialties. Sutherland said it takes about two years to get comfortable with a system."I have a high level of confidence in their expertise," Sutherland said. "We're very comfortable with what we do."Shuttles lifted off two pads during the 30 years of the program, Launch Complex 39A and Launch Complex 39B, or just "pad A" and "pad B" to those who worked on them. Built for the Apollo/Saturn V combination, the pads were identical and each had its own work force during most of the shuttle years. Though shuttles occasionally were on both pads together, the practical benefit of having two pads was to let one be refurbished while launches took place on the other.
A crawler-transporter moves the shuttle stack, mounted on a mobile launcher platform, or MLP, the three miles from the Vehicle Assembly Building to pad A, three-and-a-half miles to pad B. The MLP is anchored to steel columns on the pad surface and connected to the rest of the pad complex.The MLP holds the shuttle stack with eight bolts that are blown apart at the same time the boosters ignite to allow the shuttle to soar into space.Also, a pair of connection masts on either side of the shuttle's aft compartment is housed on the MLP. The masts contain a battery of wires, cables and the lines that run propellants into the external tank. At launch, the connectors pull back from the shuttle into the masts where armored doors close over them to protect them from the blast.
The pads are considered by some the most advanced in the world, although straight comparisons are difficult because a pad's structure is a direct reflection of the spacecraft it is hosting. A space shuttle, with its reusable engines, delta wings and 60-foot-long cargo bay, has significantly different needs than a capsule."I know that what we do out here is a lot more complicated in that we do the final flight processing, all the propellants are loaded out here," Sutherland said. "The hypergolics are loaded at the pad. I know that at other launch facilities those type tasks are done prior to arrival on the launch pad."
More than 30 years after they left Earth, NASA's twin Voyager probes are now at the edge of the solar system. Not only that, they're still working. And with each passing day they are beaming back a message that, to scientists, is both unsettling and thrilling. The message is, "Expect the unexpected.""It's uncanny," says Ed Stone of the California Institute of Technology in Pasadena, Voyager Project Scientist since 1972. "Voyager 1 and 2 have a knack for making discoveries."
Today, April 28, 2011, NASA held a live briefing to reflect on what the Voyager mission has accomplished--and to preview what lies ahead as the probes prepare to enter the realm of interstellar space in our Milky Way galaxy.The adventure began in the late 1970s when the probes took advantage of a rare alignment of outer planets for an unprecedented Grand Tour. Voyager 1 visited Jupiter and Saturn, while Voyager 2 flew past Jupiter, Saturn, Uranus and Neptune. (Voyager 2 is still the only probe to visit Uranus and Neptune.)When pressed to name the top discoveries from those encounters, Stone pauses, not for lack of material, but rather an embarrassment of riches. "It's so hard to choose," he says.Stone's partial list includes the discovery of volcanoes on Jupiter's moon Io; evidence for an ocean beneath the icy surface of Europa; hints of methane rain on Saturn's moon Titan; the crazily-tipped magnetic poles of Uranus and Neptune; icy geysers on Neptune's moon Triton; planetary winds that blow faster and faster with increasing distance from the sun."Each of these discoveries changed the way we thought of other worlds," says Stone.In 1980, Voyager 1 used the gravity of Saturn to fling itself slingshot-style out of the plane of the solar system. In 1989, Voyager 2 got a similar assist from Neptune. Both probes set sail into the void. Sailing into the void sounds like a quiet time, but the discoveries have continued.Stone sets the stage by directing our attention to the kitchen sink. "Turn on
the faucet," he instructs. "Where the water hits the sink, that's the sun, and the thin sheet of water flowing radially away from that point is the solar wind. Note how the sun 'blows a bubble' around itself."There really is such a bubble, researchers call it the "heliosphere," and it is gargantuan. Made of solar plasma and magnetic fields, the heliosphere is about three times wider than the orbit of Pluto. Every planet, asteroid, spacecraft, and life form belonging to our solar system lies inside.The Voyagers are trying to get out, but they're not there yet. To locate them, Stone peers back into the sink: "As the water [or solar wind] expands, it gets thinner and thinner, and it can't push as hard. Abruptly, a sluggish, turbulent ring forms. That outer ring is the heliosheath--and that is where the Voyagers are now."The heliosheath is a very strange place, filled with a magnetic froth no spacecraft has ever encountered before, echoing with low-frequency radio bursts heard only in the outer reaches of the solar system, so far from home that the sun is a mere pinprick of light."In many ways, the heliosheath is not like our models predicted," says Stone.In June 2010, Voyager 1 beamed back a startling number: zero. That's the outward velocity of the solar wind where the probe is now. No one thinks the solar wind has completely stopped; it may have just turned a corner. But which way? Voyager 1 is trying to figure that out through a series of "weather vane" maneuvers, in which the spacecraft turns itself in a different direction to track the local breeze. The old spacecraft still has some moves left, it seems.No one knows exactly how many more miles the Voyagers must travel before they "pop free" into interstellar space. Most researchers believe, however, that the end is near. "The heliosheath is 3 to 4 billion miles in thickness," estimates Stone. "That means we'll be out within five years or so."There is plenty of power for the rest of the journey. Both Voyagers are energized by 
the radioactive decay of a Plutonium 238 heat source. This should keep critical subsystems running through at least 2020.After that, he says, "Voyager will become our silent ambassador to the stars."Each probe is famously equipped with a Golden Record, literally, a gold-coated copper phonograph record. It contains 118 photographs of Earth; 90 minutes of the world's greatest music; an audio essay entitled Sounds of Earth (featuring everything from burbling mud pots to barking dogs to a roaring Saturn 5 liftoff); greetings in 55 human languages and one whale language; the brain waves of a young woman in love; and salutations from the secretary general of the United Nations. A team led by Carl Sagan assembled the record as a message to possible extraterrestrial civilizations that might encounter the spacecraft.
ightest meteor seen by their network in almost three years of operation. On May 20, 2011, at 9:47 p.m. CDT, a six-foot diameter fragment of an unknown comet entered the atmosphere approximately 66 miles above the city of Macon, Ga., traveling northwest at a speed of some 24 miles per second (86,000 mph). At this velocity, the boulder-sized "dirty snowball" possessed an energy or striking power somewhere between 500-1000 tons of TNT.
video below illustrates. Because the video is slowed to one-third of the actual real-time speed, it's easy to spot the large fragments coming off in the wake after the flares.
