Posted on by Mark Mortimer

Book Review: Astronomy Hacks

This hack book can be taken two ways. One is as a reference to look up solutions to problems or seek a reference for a better method. Two is as a complete back grounder for the beginner and higher level amateur astronomer. Within it are 65 distinct hacks grouped into four chapters; Getting Started, Observing Hacks, Scope Hacks and Accessory Hacks. No embellishments obscure the text. There are only the hacks, each relating to astronomy the same way a Clymers manual refers to motorcycle repairs. No extenuating plots nor complex character development obstructs the wording. This book just lists lots of techniques, hints and recommendations.

The first chapter, Getting Started, has enough detail to guide the beginner or assist the intermediate practitioner. The standard encapsulation of binocular and telescope types ensues. To provide an example of the depth of detail, consider the binocular. The discussion includes; magnification, aperture, exit pupil, eye relief, field of view, interpupilary distance, prism type and lens coatings. A summary list recommends choices for various budget ranges ($75 to $5000) and gives recommendations on certain manufacturers and models.

The telescope selection hack is equally detailed, with descriptions of the three main types; reflector, refractors and catadioptric as well as criteria and recommendations. The authors are admitted fans of Dobsonian telescopes and tend to give more attention to this type both here and elsewhere in the book.

Safety, as its own hack or as a backdrop for many other hacks, appears throughout. Most is for personal safety, whether by staying in groups or not dropping large, heavy mirrors on toes. Perhaps the recommendations to bring a firearm for protection against four legged predators goes a bit far. The repeated references to courtesy for group viewing is just one of the many indicators of the wealth of the author’s experience.

The chapter for observing hacks includes, amongst others, the principles of light, a comprehensive biological description of our eye’s receivers, and a method to running a Messier Marathon. This chapter revolves around the purpose or goals of amateur astronomers. Accepting that these aren’t planning on detecting new stars or planets, the authors clearly convey the simple pleasures of viewing. Whether taking copious notes, simple sketches or photographs, the rewards are many and admittedly differ with each person. Simple hacks to improve style or refine goals, aid in refining the reward.

The scope hacks essentially look at scope maintenance and they can get complex. There are step by step cleaning instructions for a 10 pound mirror, including swishing it under the faucet for minutes. The same goes for collimation, with its consideration of Strehl values and diffraction spikes. But equally, the reasoning and the simple instructions convince and empower the reader to take charge of their viewing capabilties.

The last chapter, Accessories Hacks, is chock full of the little tips to branching out. Eyepieces and filters get a thorough treatment. Light proofing your vehicle or using software to build custom star charts round out the suggestions.

In all, whether as a reference or as an introductory read, this book delivers. The background and justification for the hacks give sufficient information to believe in their value without overtaxing the brain. Neat hints, like keeping red pens away from night sites, help any observer from commiting blunders. The table of contents and index simply and easily guide readers. While sketches, illustrations and photographs clarify many of the sublte points. There’s even a note on the proper pronunciation of Greek letters.

With simple prose copiously sprinkled with personal, humorous anecdotes, the reading is a pleasure. Many references to manufacturers and equipment costs aid in selections today, though they probably won’t stand the test of time. As well, there is very little on astro-photography. The authors simply say that this activity demands much practise and much equipment. Fair enough, but given the upsurge in computer literates, this area cries for more information.

Reading car repair manuals helps fix a car’s problem or learn more about fixing cars in general. The same can be said for Robert and Barbara Thompson’s book, Astronomy Hacks. Each hack includes details, hints and tips to embellish a viewer’s night time activities. Most of all it ably empowers you to take charge of your hobby and make the most of astronomical viewing.

Click here to visit Amazon.com and read more reviews online or purchase a copy.

Review by Mark Mortimer

Posted on by Fraser Cain

Japanese Astro-E2 Satellite Launched

Artist illuatration of Astro-E2. Image credit: JAXA. Click to enlarge.
The M-V Launch Vehicle No. 6 (M-V-6) with the 23rd scientific satellite (ASTRO-EII) onboard was launched at 12:30 p.m. on July 10, 2005 (Japan Standard Time, JST) from the Uchinoura Space Center (USC). The launcher was set to a vertical angle of 80.2 degrees, and the flight azimuth was 87.6 degrees.

The launch vehicle flew smoothly, and the third stage motor was ignited at 205 seconds after liftoff. The third stage flight was also smooth, and after its motor burnout, it was confirmed to be safely injected into its scheduled orbit of an apogee altitude of approximately 247 km and a perigee altitude of approximately 560 km with an inclination of approximately 31.4 degrees.

JAXA received signals from the ASTRO-EII at the Santiago tracking station and the USC, and from those signals we verified that the ASTRO-EII had successfully separated.

The in-orbit ASTRO-EII was given the International Designator of 2005-025A and a nickname of “Suzaku.”

The weather at the time of the launch was slightly cloudy with a wind speed of 7m/s from the west-south-west, and the temperature was 31.7 degrees Celsius.

Original Source: JAXA News Release

Posted on by Fraser Cain

How Much Material Was Blasted Off By Deep Impact?

X-ray detections from Tempel 1 after Deep Impact collision. Image credit: Swift. Click to enlarge.
Here come the X-rays, on cue. Scientists studying the Deep Impact collision using NASA’s Swift satellite report that comet Tempel 1 is getting brighter and brighter in X-ray light with each passing day.

The X-rays provide a direct measurement of how much material was kicked up in the impact. This is because the X-rays are created by the newly liberated material lifted into the comet’s thin atmosphere and illuminated by the high-energy solar wind from the Sun. The more material liberated, the more X-rays are produced.

Swift data of the water evaporation on comet Tempel 1 also may provide new insights into how solar wind can strip water from planets such as Mars.

“Prior to its rendezvous with the Deep Impact probe, the comet was a rather dim X-ray source,” said Dr. Paul O’Brien of the Swift team at the University of Leicester. “How things change when you ram a comet with a copper probe traveling over 20,000 miles per hour. Most of the X-ray light we detect now is generated by debris created by the collision. We can get a solid measurement of the amount of material released.”

“It takes several days after an impact for surface and sub-surface material to reach the comet’s upper atmosphere, or coma,” said Dr. Dick Willingale, also of the University of Leicester. “We expect the X-ray production to peak this weekend. Then we will be able to assess how much comet material was released from the impact.”

Based on preliminary X-ray analysis, O’Brien estimates that several tens of thousands of tons of material were released, enough to bury Penn State’s football field under 30 feet of comet dust. Observations and analysis are ongoing at the Swift Mission Operations Center at Penn State University as well as in Italy and the United Kingdom.

Swift is providing the only simultaneous multi-wavelength observation of this rare event, with a suite of instruments capable of detecting visible light, ultraviolet light, X-rays, and gamma rays. Different wavelengths reveal different secrets about the comet.

The Swift team hopes to compare the satellite’s ultraviolet data, collected hours after the collision, with the X-ray data. The ultraviolet light was created by material entering into the lower region of the comet’s atmosphere; the X-rays come from the upper regions. Swift is a nearly ideal observatory for making these comet studies, as it combines both a rapidly responsive scheduling system with both X-ray and optical/UV instruments in the same satellite.

“For the first time, we can see how material liberated from a comet’s surface migrates to the upper reaches of its atmosphere,” said Prof. John Nousek, Director of Mission Operations at Penn State. “This will provide fascinating information about a comet’s atmosphere and how it interacts with the solar wind. This is all virgin territory.”

Nousek said Deep Impact’s collision with comet Tempel 1 is like a controlled laboratory experiment of the type of slow evaporation process from solar wind that took place on Mars. The Earth has a magnetic field that shields us from solar wind, a particle wind composed mostly of protons and electrons moving at nearly light speed. Mars lost its magnetic field billions of years ago, and the solar wind stripped the planet of water.

Comets, like Mars and Venus, have no magnetic fields. Comets become visible largely because ice is evaporated from their surface with each close passage around the Sun. Water is dissociated into its component atoms by the bright sunlight and swept away by the fast-moving and energetic solar wind. Scientists hope to learn about this evaporation process on Tempel 1 now occurring quickly — over the course of a few weeks instead of a billion years — as the result of a planned, human intervention.

Swift’s “day job” is detecting distant, natural explosions called gamma-ray bursts and creating a map of X-ray sources in the universe. Swift’s extraordinary speed and agility enable scientists to follow Tempel 1 day by day to see the full effect from the Deep Impact collision.

The Deep Impact mission is managed by NASA’s Jet Propulsion Laboratory, Pasadena, California. Swift is a medium-class NASA explorer mission in partnership with the Italian Space Agency and the Particle Physics and Astronomy Research Council in the United Kingdom, and is managed by NASA Goddard. Penn State controls science and flight operations from the Mission Operations Center in University Park, Pennsylvania. The spacecraft was built in collaboration with national laboratories, universities and international partners, including Penn State University; Los Alamos National Laboratory, New Mexico; Sonoma State University, Rohnert Park, Calif.; Mullard Space Science Laboratory in Dorking, Surrey, England; the University of Leicester, England; Brera Observatory in Milan; and ASI Science Data Center in Frascati, Italy.

Original Source: PSU News Release

Posted on by Fraser Cain

Transit Method Turns Up Planets

Perhaps 1 in 4 stars have planets. Image credit: Hubble. Click to enlarge.
In the past decade, more than 130 extrasolar planets have been discovered to date. Most of these have been found using a technique that measures tiny changes in a star’s radial velocity, the speed of its motion relative to Earth. In a talk at a recent symposium on extrasolar planets, astronomer Alan Boss, of the Carnegie Institution of Washington, presented this overview of the difficult measurements – and the profound discoveries – made by planet-hunters using the radial-velocity technique.

In 1991, Michel Mayor and Antoine Duquennoy published a classic survey of binary stars in our solar neighborhood. They found all the binary companions that they could, but there were another 200 or so G-type stars that didn’t seem to have any binary companions. Subsequently, Michel Mayor, along with Didier Queloz, decided to look at these 200-odd stars, potential solar analogs, to see if they had planetary systems. The technique they used involved looking for stellar wobbles, cyclical changes in the stars’ radial velocity, induced by the gravitational tug of orbiting planets.

In the spring of 1994, they installed a new spectrometer on their telescope at the Haute Provence Observatory, ELODIE, which had a resolution of about 13 meters per second. This was just about the right level to be able to see the velocity wobble, the Doppler wobble, induced in the Sun by a Jupiter-like planet. By the end of 1994 they had noticed a very interesting wobble in a star called 51 Peg.

Unfortunately, 51 Peg at that point was getting closer and closer to the Sun and couldn’t be observed, so they had to take a 6-month sabbatical, and come back in the summer of 1995 and start looking at 51 Peg again. They had an 8-night observing run at the Haute Provence Observatory, and by the end of that observing run, they were ready to go to Nature and publish.

The curve they produced fit a model of 51 Peg, a solar-type star, being orbited by a planet with roughly a half of a Jupiter mass, on a nice, circular orbit. The only problem was that the object had an orbital period of 4.23 days. It was orbiting in at about 0.05 AU, nowhere near where people had been expecting to find Jupiter-mass planets. So it was a bit of a puzzle. But it was clear early on that this had to be a planet, which perhaps had formed farther out and migrated in. That was the only way to explain how it could exist at that location.

The next step was to see if anyone else could reproduce the result. Because, of course, the critical problem with the planet around Barnard’s star was that no one could confirm it. There were several other planet-hunting efforts underway at the time in 1995, but the folks who got to the telescope first were Paul Butler and Geoff Marcy. They were able to confirm 51 Peg’s planet, with even smaller scatter than the original discovery measurements.

We realized at this point that the field of extrasolar planets had truly been born. In October 1995 a new era was entered, where we actually had convincing, solid proof of the existence of extrasolar planets around normal stars.

Now Geoff and Paul had been working in this field for many years. They had actually started seriously around 1987, and so they had a lot of data ready to analyze. They immediately began to reduce all of their data, looking for short period orbits, took some more measurements, and by January of 1996, they were able to announce a couple more planets. One of them, 47 UMa b, was considerably more reassuring a planet than the one discovered orbiting 51 Peg. It was roughly a 2 or 3 Jupiter-mass object orbiting at a distance of 2 or so AU, more like what we were expecting to find based on the planets in our own solar system. We now know that this is a multiple-planet system, but at the time they fit it with a single Keplerian orbit.

Almost all of the known extrasolar planets have been found using this radial-velocity technique; roughly 117 planets have been discovered that way. But there’s another way of finding planets, transit detection. The first transit detection was achieved by David Charboneau and colleagues and separately by Greg Henry and colleagues in 2000. This was a planet which had been found originally by radial velocity, but then these other researchers went on and did both ground-based and later Hubble photometry of the host star and found a really wonderful light curve, indicative of the planet passing in front of the star, dimming its light slightly. The initial detection by Charbonneau’s team was done, believe it or not, using a 4-inch telescope in a parking lot in Boulder, Colorado.

The dip in the star’s light amplitude is about 1.5 percent, so it’s truly amazing that this very first transit detection could have been made by a good amateur telescope. When HST went back and re-did the photometry with much higher precision, it produced an incredibly beautiful light curve, which is so precise you could use it to try to search for moons around the planet and place limits on how large they could be.

So transits are now coming into their own. I think they’re the second leading way of finding planets. Six planets have been discovered by transits now.

Original source: NASA Astrobiology

Posted on by Fraser Cain

No, Mars Won’t Look as Big as the Moon

Hubble Space Telescope view of Mars at its closest point 2 years ago. Image credit: Hubble. Click to enlarge.
There’s a rumor going around. You might have heard it at a 4th of July BBQ or family get-together. More likely you’ve read it on the Internet. It goes like this:

“The Red Planet is about to be spectacular.”

“Earth is catching up with Mars [for] the closest approach between the two planets in recorded history.”

“On August 27th ? Mars will look as large as the full moon.”

And finally, “NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN.”

Those are snippets from a widely-circulated email. Only the first sentence is true. The Red Planet is about to be spectacular. The rest is a hoax.

Here are the facts: Earth and Mars are converging for a close encounter this year on October 30th at 0319 Universal Time. Distance: 69 million kilometers. To the unaided eye, Mars will look like a bright red star, a pinprick of light, certainly not as wide as the full Moon.

Disappointed? Don’t be. If Mars did come close enough to rival the Moon, its gravity would alter Earth’s orbit and raise terrible tides.

Sixty-nine million km is good. At that distance, Mars shines brighter than anything else in the sky except the Sun, the Moon and Venus. The visual magnitude of Mars on Oct. 30, 2005, will be -2.3. Even inattentive sky watchers will notice it, rising at sundown and soaring overhead at midnight.

You might remember another encounter with Mars, about two years ago, on August 27, 2003. That was the closest in recorded history, by a whisker, and millions of people watched as the distance between Mars and Earth shrunk to 56 million km. This October’s encounter, at 69 million km, is similar. To casual observers, Mars will seem about as bright and beautiful in 2005 as it was in 2003.

Although closest approach is still months away, Mars is already conspicuous in the early morning. Before the sun comes up, it’s the brightest object in the eastern sky, really eye-catching. If you have a telescope, even a small one, point it at Mars. You can see the bright icy South Polar Cap and strange dark markings on the planet’s surface.

One day people will walk among those dark markings, exploring and prospecting, possibly mining ice from the polar caps to supply their settlements. It’s a key goal of NASA’s Vision for Space Exploration: to return to the Moon, to visit Mars and to go beyond.

Every day the view improves. Mars is coming–and that’s no hoax.

Original Source: NASA News Release

Posted on by Fraser Cain

Shuttle Exhaust Can Make Clouds in Antarctica

Space shuttle Discovery on the launch pad. Image credit: NASA. Click to enlarge.
A new study, funded in part by the Naval Research Laboratory and the National Aeronautics and Space Administration (NASA) reports that exhaust from the space shuttle can create high-altitude clouds over Antarctica mere days following launch, providing valuable insight to global transport processes in the lower thermosphere[mhs1]. The same study also finds that the shuttle’s main engine exhaust plume carries small quantities of iron that can be observed from the ground, half a world away.

The international team of authors of the study, to appear in the July 6 issue of Geophysical Research Letters, used the STS-107 Shuttle mission as a case study to show that exhaust released in the lower thermosphere, near 110 kilometers altitude, can form Antarctic polar mesospheric clouds (PMCs). The thermosphere is the highest layer in our atmosphere, with the mesosphere (between 50-90 kilometers above the Earth), stratosphere, and troposphere below.

New observations presented by the research team from the Global Ultraviolet Imager (GUVI) on NASA’s Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite reveal transport of the STS-107 exhaust into the southern hemisphere just two days after the January 2003 launch. Water from the exhaust ultimately led to a significant burst of PMCs during the 2002-2003 southern polar summer, observed by the Solar Backscatter Ultraviolet (SBUV) satellite experiment. The inter-hemispheric transport followed by Antarctic PMC formation were unexpected.

PMCs, also known as noctilucent clouds, appear near 83 kilometers altitude and are made up of water ice particles created through microphysical processes of nucleation, condensation, and sedimentation. They typically appear in the frigid polar summer mesosphere where temperatures plummet below 130? Kelvin (-220? F). Little is known about the specific processes that lead to PMC formation.

According to the study’s lead author, Dr. Michael Stevens, a research physicist at the E.O. Hulburt Center for Space Research at the Naval Research Laboratory, the research produced multiple groundbreaking science results.

“This research is exciting in that it extends a new explanation for the formation of these clouds by demonstrating the global effect of a Shuttle exhaust plume in a region of the atmosphere that has traditionally not been well understood,” said Stevens.

Some believe that the impact of anthropogenic change in the lower atmosphere is reflected in these upper atmospheric clouds. Although historically PMCs have only been seen in the polar region, in recent years PMCs have been spotted at lower latitudes as far south as [mhs2]Colorado and Utah, renewing interest and sparking debate on the implications. However, the findings of this work, “call into question the interpretation of the impact of late 20th century PMC trends solely in terms of global climate change,” Stevens said. The team concludes that the water from a space shuttle’s exhaust plume can contribute a remarkable 10-20 percent to PMCs observed during one summer season in Antarctica.

A key piece of data that confirmed the plume’s arrival in Antarctica was the ground-based observation of iron atoms near 110 km. The presence of iron at this altitude originally perplexed scientists because there is no known natural source there. The data imply that iron ablated, or vaporized, by the main engines of the Shuttle was transported along with the water plume, arriving in Antarctica three to four days after the January 2003 launch. Both the water plume and the presence of iron demonstrate that the mean southward wind inferred from the team’s data is much faster than gleaned from global circulation models or wind climatologies.

“This tells us something new and exciting about transport in this region of the atmosphere,” said Stevens. “It can be so fast that a shuttle plume can form ice over Antarctica before other loss processes can really take effect. We must take great care in interpreting the long-term implications to observations and features of these clouds because of this contribution from the shuttle and the potential contribution from many other smaller launch vehicles.”

NRL and NASA funded the study, with contributions from the National Science Foundation, the British Antarctic Survey in Cambridge, United Kingdom, and the University of Illinois, Urbana-Champaign. Other researchers on the study include Robert Meier of George Mason University, Fairfax, Va.; Xinzhao Chu of the University of Illinois, Urbana-Champaign; Matthew DeLand of Science Systems & Applications, Inc., Lanham, Md.; and John Plane of the University of East Anglia, Norwich, United Kingdom.

Original Source: NRL News Release

Posted on by Fraser Cain

Microquasar Puzzles Astronomers

Computer illustration of microquasar LS5039. Image credit: PPARC. Click to enlarge.
In a recent issue of Science Magazine, the High Energy Stereoscopic System (H.E.S.S.) team of international astrophysicists reports the discovery of another new type of very high energy (VHE) gamma ray source.

Gamma-rays are produced in extreme cosmic particle accelerators such as supernova explosions and provide a unique view of the high energy processes at work in the Milky Way. VHE gamma-ray astronomy is still a young field and H.E.S.S. is conducting the first sensitive survey at this energy range, finding previously unknown sources.

The object that is producing the high energy radiation is thought to be a ‘microquasar’. These objects consist of two stars in orbit around each other. One star is an ordinary star, but the other has used up all its nuclear fuel, leaving behind a compact corpse. Depending on the mass of the star that produced it, this compact object is either a neutron star or a black hole, but either way its strong gravitational pull draws in matter from its companion star. This matter spirals down towards the neutron star or the black hole, in a similar way to water spiraling down a plughole.

However, sometimes the compact object receives more matter than it can cope with. The material is then squirted away from the system in a jet of matter moving at speeds close to that of light, resulting in a microquasar. Only a few such objects are known to exist in our galaxy and one of them, an object called LS5039, has now been detected by the H.E.S.S. team.

In fact, the real nature LS5039 is something of a mystery. It is not clear what the compact object is. Some of the characteristics suggest it is a neutron star, some that it is a black hole. Not only that, but the jet isn’t much of a jet; although it is moving at about 20% of the speed of light, which might seem a lot, in the context of these objects it’s actually quite slow.

Nor is it clear how the gamma rays are being produced. As Dr. Guillaume Dubus of the Ecole Polytechnique points out “We really shouldn’t have detected this object. Very high energy gamma rays emitted close to the companion star are more likely to be absorbed, creating a matter/antimatter cascade, than escape from the system.”

Dr Paula Chadwick of the University of Durham adds “It’s very exciting to have added another class of object to the growing catalogue of gamma ray sources. It’s an intriguing object – it will take more observations to work out what is going on in there.”

The H.E.S.S. array is ideal for finding new VHE gamma ray objects; because it’s wide field of view (ten times the diameter of the Moon) means that it can survey the sky and discover previously unknown sources.

The results were obtained using the High Energy Stereoscopic System (H.E.S.S.) telescopes in Namibia, in South-West Africa. This system of four 13 m diameter telescopes is currently the most sensitive detector of VHE gamma-rays – radiation that is a million, million times more energetic than the visible light. These high energy gamma rays are quite rare even for relatively strong sources; only about one gamma ray per month hits a square metre at the top of the Earth’s atmosphere. Also, since they are absorbed in the atmosphere, a direct detection of a significant number of the rare gamma rays would require a satellite of huge size. The H.E.S.S. telescopes employ a trick – they use the atmosphere as detector medium. When gamma rays are absorbed in the air, they emit short flashes of blue light, named Cherenkov light, lasting a few billionths of a second. This light is collected by the H.E.S.S. telescopes with large mirrors and extremely sensitive cameras and can be used to create images of astronomical objects as they appear in gamma-rays.

The H.E.S.S. telescopes represent several years of construction effort by an international team of more than 100 scientists and engineers from Germany, France, the UK, Ireland, the Czech Republic, Armenia, South Africa and the host country Namibia. The instrument was inaugurated in September 2004 by the Namibian Prime Minister, Theo-Ben Guirab, and its first data have already resulted in a number of important discoveries, including the first astronomical image of a supernova shock wave at the highest gamma-ray energies.

Original Source: PPARC News Release

Posted on by Fraser Cain

Seas are Rising Faster than Ever

Artist illustration of NASA satellite measuring sea levels. Image credit: NASA/JPL. Click to enlarge.
For the first time, NASA has the tools and expertise to understand the rate at which sea level is changing, some of the mechanisms that drive those changes and the effects that sea level change may have worldwide.

“It’s estimated that more than 100 million lives are potentially impacted by a one-meter (3.3-foot) increase in sea level,” said Dr. Waleed Abdalati, head of the Cryospheric Sciences Branch at NASA’s Goddard Space Flight Center, Greenbelt, Md. “When you consider this information, the importance of learning how and why these changes are occurring becomes clear,” he added.

Although scientists have directly measured sea level since the early part of the 20th century, it was not known how many of the observed changes in sea level were real and how many were related to upward or downward movement of the land. Now satellites have changed that by providing a reference by which changes in ocean height can be determined regardless of what the nearby land is doing. With new satellite measurements, scientists are able to better predict the rate at which sea level is rising and the cause of that rise.

“In the last 50 years sea level has risen at an estimated rate of .18 centimeters (.07 inches) per year, but in the last 12 years that rate appears to be .3 centimeters (.12 inches) per year. Roughly half of that is attributed to the expansion of ocean water as it has increased in temperature, with the rest coming from other sources,” said Dr. Steve Nerem, associate professor, Colorado Center for Astrodynamics Research, University of Colorado, Boulder.

Another source of sea level rise is the increase in ice melting. Evidence shows that sea levels rise and fall as ice on land grows and shrinks. With the new measurements now available, it’s possible to determine the rate at which ice is growing and shrinking.

“We’ve found the largest likely factor for sea level rise is changes in the amount of ice that covers the Earth. Three-fourths of the planet’s freshwater is stored in glaciers and ice sheets or the equivalent of about 67 meters (220 feet) of sea level,” said Dr. Eric Rignot, principal scientist for the Radar Science and Engineering Section at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Ice cover is shrinking much faster than we thought, with over half of recent sea level rise due to the melting of ice from Greenland, West Antarctica’s Amundsen Sea and mountain glaciers,” he said.

Additionally, NASA scientists and partner researchers now are able to measure and monitor the world’s waters globally in a sustained and comprehensive way using a combination of satellite observations and sensors in the ocean. By integrating the newly available satellite and surface data, scientists are better able to determine the causes and significance of current sea level changes.

“Now the challenge is to develop an even deeper understanding of what is responsible for sea level rise and to monitor for possible future changes. That’s where NASA’s satellites come in, with global coverage and ability to examine the many factors involved,” said Dr. Laury Miller, chief of the National Oceanic and Atmospheric Administration Laboratory for Satellite Altimetry, Washington, D.C.

NASA works with agency partners such as the National Oceanic and Atmospheric Administration and the National Science Foundation to explore and understand sea level change. Critical resources that NASA brings to bear on this issue include such satellites as:

— Topex/Poseidon and Jason, the U.S. portions of which are managed by JPL, which use radar to map the precise features of the oceans’ surface, measuring ocean height and monitoring ocean circulation;

— Ice, Cloud and Land Elevation Satellite (IceSat), which studies the mass of polar ice sheets and their contributions to global sea level change;

— Gravity Recovery And Climate Experiment (Grace), also managed by JPL, which maps Earth’s gravitational field, allowing us to better understand movement of water throughout the Earth.

Original Source: NASA News Release

Posted on by Fraser Cain

STS-114 Countdown Begins July 10

Space shuttle Discovery moving from the Vehicle Assembly building. Image credit: NASA. Click to enlarge.
NASA will begin the countdown for the Return to Flight launch of Space Shuttle Discovery on mission STS-114 July 10 at 6 p.m. EDT, 43 hours before liftoff. Discovery’s seven-member crew will test new equipment and procedures to increase the safety of the Shuttle and deliver spare parts, water and supplies to the International Space Station.

The Kennedy Space Center (KSC) launch team will conduct the countdown from Firing Room 3 of the Launch Control Center. The countdown includes nearly 27 hours of built-in hold time leading to a preferred launch time at about 3:51 p.m. on July 13 with a launch window extending about five minutes.

This historic mission is the 114th Space Shuttle flight and the 17th U.S. flight to the International Space Station. STS-114 is scheduled to last about 12 days with a planned KSC landing at about 11:01 a.m. EDT on July 25.

Discovery rolled into KSC’s Orbiter Processing Facility (OPF) on Aug. 22, 2001, after returning from its last mission STS-105 in August 2001 and undergoing an Orbiter Major Modification period. The Shuttle rolled out of OPF bay 3 and into the Vehicle Assembly Building (VAB) on March 29. While in VAB high bay 1, Discovery was mated to its redesigned External Tank and Solid Rocket Boosters. The entire Space Shuttle stack was transferred to Launch Pad 39B on April 7.

In order to allow for the addition of a new heater to the External Tank, Space Shuttle Discovery was rolled back to the VAB on May 26 for that modification to be performed. Discovery was removed from its External Tank and attached to a new tank originally scheduled to fly with orbiter Atlantis on mission STS-121, the second Return to Flight mission.

Discovery was rolled back out to Launch Pad 39B on June 15 in preparation for the July launch window.

On mission STS-114, the crew will perform inspections on orbit for the first time of all of the Reinforced Carbon-Carbon (RCC) panels on the leading edge of the wings and the Thermal Protection System tiles using the new Canadian-built Orbiter Boom Sensor System and the data from 176 impact and temperature sensors. Mission Specialists will also practice repair techniques on RCC and tile samples during a spacewalk in the payload bay.

In the payload bay, the Multi-Purpose Logistic Module Raffaello, built by the Italian Space Agency, will carry 11 racks with supplies, hardware, equipment and the Human Research Facility-2.

During two additional spacewalks, the crew will install the External Stowage Platform-2, equipped with spare part assemblies, and a replacement Control Moment Gyroscope contained in the Lightweight Multi-Purpose Experiment Support Structure.

The STS-114 crew includes Commander Eileen Collins, Pilot James Kelly, and Mission Specialists Soichi Noguchi, Stephen Robinson, Andrew Thomas, Wendy Lawrence and Charles Camarda.

Original Source:NASA News Release