Posts Tagged ‘August.’

Jupiter-Bound Space Probe Captures Earth And Moon

August 31, 2011 Leave a comment

This image of Earth (on the left) and the moon (on the right) was taken by NASA's Juno spacecraft on Aug. 26, 2011, when the spacecraft was about 6 million miles (9.66 million kilometers) away.  Image credit: NASA/JPL-Caltech

This image of Earth (on the left) and the moon (on the right) was taken by NASA's Juno spacecraft on Aug. 26, 2011, when the spacecraft was about 6 million miles (9.66 million kilometers) away. Image credit: NASA/JPL-Caltech

On its way to the biggest planet in the solar system — Jupiter, NASA’s Juno spacecraft took time to capture its home planet and its natural satellite — the moon.
“This is a remarkable sight people get to see all too rarely,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “This view of our planet shows how Earth looks from the outside, illustrating a special perspective of our role and place in the universe. We see a humbling yet beautiful view of ourselves.”

The image was taken by the spacecraft’s camera, JunoCam, on Aug. 26 when the spacecraft was about 6 million miles (9.66 million kilometers) away. The image was taken as part of the mission team’s checkout of the Juno spacecraft. The team is conducting its initial detailed checks on the spacecraft’s instruments and subsystems after its launch on Aug. 5.

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Uncovering the Secrets of the Great Supernova

August 29, 2011 Leave a comment

Credit: Peter Nugent and the Palomar Transient Factory

Credit: Peter Nugent and the Palomar Transient Factory

A once-in-a-lifetime nearby stellar explosion now unfolding in a neighboring galaxy has astronomers at the W. M. Keck Observatory scrambling to ask questions that can’t be answered at any other ground-based telescope in the world. The first big question: What causes this pivotally important type of stellar cataclysm?

Observing this spectacular supernova, dubbed PTF11kly, began on August 24, with the detection of the explosion in the nearby Pinwheel Galaxy, a.k.a. M101, by the automated Palomar Transient Factory (PTF) survey. That survey is designed to detect short-lived astronomical events as they happen.

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Cassini Closes in on Saturn’s Tumbling Moon Hyperion

August 29, 2011 Leave a comment

NASA's Cassini spacecraft obtained this unprocessed image of Saturn's moon Hyperion on Aug. 25, 2011. Image credit: NASA/JPL-Caltech/Space Science Institute

NASA’s Cassini spacecraft captured new views of Saturn’s oddly shaped moon Hyperion during its encounter with this cratered body on Thursday, Aug. 25. Raw images were acquired as the spacecraft flew past the moon at a distance of about 15,500 miles (25,000 kilometers), making this the second closest encounter.
Hyperion is a small moon — just 168 miles (270 kilometers) across. It has an irregular shape and surface appearance, and it rotates chaotically as it tumbles along in orbit. This odd rotation prevented scientists from predicting exactly what terrain the spacecraft’s cameras would image during this flyby.

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A Planet Made of Diamond

August 25, 2011 Leave a comment

An artist's visualisation of the pulsar and its orbiting planet. Image credit – Swinburne Astronomy Productions

An artist's visualisation of the pulsar and its orbiting planet. Image credit – Swinburne Astronomy Productions

A once-massive star that’s been transformed into a small planet made of diamond: that’s what astronomers think they’ve found in our Milky Way.

The discovery has been made by an international research team, led by Professor Matthew Bailes of Swinburne University of Technology in Melbourne, Australia, and is reported in today’s [Thursday August 25, 2011] issue of the journal Science.

Although bizarre, the “diamond planet” is in accord with our current picture of how certain binary star systems form.

The researchers, from Australia, Germany, Italy, the UK and the USA first detected an unusual star called a pulsar using the 64-m Parkes radio telescope of the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) and followed up their discovery with the Lovell radio telescope in the UK and one of the Keck telescopes in Hawaii.

Pulsars are small spinning stars about 20 km in diameter — the size of a small city — that emit a beam of radio waves. As the star spins and the radio beam sweeps repeatedly over Earth, radio telescopes detect a regular pattern of radio pulses.

For the newly discovered pulsar, known as PSR J1719-1438, the astronomers noticed that the arrival times of the pulses were systematically modulated. They concluded that this was due to the gravitational pull of a small companion planet, orbiting the pulsar in a binary system.

The pulsar and its planet are part of the Milky Way’s plane of stars and lie 4,000 light-years away in the constellation of Serpens (the Snake). The system is about an eighth of the way towards the galactic center from the Earth.

The modulations in the radio pulses tell astronomers several things about the planet.

First, it orbits the pulsar in just two hours and ten minutes, and the distance between the two objects is 600,000 km — a little less than the radius of our Sun.

Second, the companion must be small, less than 60,000 km (that’s about five times the Earth’s diameter). The planet is so close to the pulsar that, if it were any bigger, it would be ripped apart by the pulsar’s gravity.

But despite its small size, the planet has slightly more mass than Jupiter.

“This high density of the planet provides a clue to its origin”, said Professor Bailes.

A Star Is Torn

The team thinks that the “diamond planet” is all that remains of aonce-massive star, most of whose matter was siphoned off towards the pulsar.

Pulsar J1719-1438 is a very fast-spinning pulsar — what’s called a millisecond pulsar. Amazingly, it rotates more than 10,000 times per minute, and has a mass of about 1.4 times that of our Sun, but is only 20 km in diameter. About 70 per cent of millisecond pulsars have companions of some kind. Astronomers think it is the companion that, in its star form, transforms an old, dead pulsar into a millisecond pulsar by transferring matter and spinning it up to a very high speed. The result is a fast-spinning millisecond pulsar with a shrunken companion — most often a so-called white dwarf.

“We know of a few other systems, called ultra-compact low-mass X-ray binaries, that are likely to be evolving according to the scenario above and may likely represent the progenitors of a pulsar like J1719-1438,” said team member Dr. Andrea Possenti, Director at INAF-Osservatorio Astronomico di Cagliari.

But pulsar J1719-1438 and its companion are so close together that the companion can only be a very stripped-down white dwarf, one that has lost its outer layers and over 99.9 per cent of its original mass.

“This remnant is likely to be largely carbon and oxygen, because a star made of lighter elements like hydrogen and helium would be too big to fit the measured orbit,” said Dr. Michael Keith (CSIRO), one of the research team members.

The density means that this material is certain to be crystalline: that is, a large part of the star may be similar to a diamond.

“The ultimate fate of the binary is determined by the mass and orbital period of the donor star at the time of mass transfer. The rarity of millisecond pulsars with planet-mass companions means that producing such exotic planets is the exception rather than the rule, and requires special circumstances,” said Dr. Benjamin Stappers from the University of Manchester.

The team found pulsar J1719-1438 among almost 200,000 gigabytes of data using special codes on supercomputers at Swinburne University of Technology in Australia, The University of Manchester in the UK, and the INAF-Osservatorio Astronomico di Cagliari, Italy.

The discovery was made during a systematic search for pulsars over the whole sky that also involves the 100 meter Effelsberg radio telescope of the Max-Planck-Institute for Radio Astronomy (MPIfR) in Germany. “This is the largest and most sensitive survey of this type ever conducted. We expected to find exciting things, and it is great to see it happening. There is more to come!,” said Professor Michael Kramer, Director at the MPIfR.

Professor Matthew Bailes leads the “Dynamic Universe” theme in a new wide-field astronomy initiative in Australia, the Centre of Excellence for All-sky Astrophysics (CAASTRO).

The discovery of the new binary system is of special significance for him and fellow team member Professor Andrew Lyne, who jointly ignited the whole pulsar-planet field in 1991 with what proved to an erroneous claim of the first extra-solar planet. The next year though the first extra-solar planetary system was discovered around the pulsar PSR B1257+12.

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Seattle Students Chat With Space Station Astronauts On Monday

August 25, 2011 Leave a comment

Students gathered at the Museum of Flight in Seattle will make a long distance call to astronauts aboard the International Space Station at approximately 1:35 p.m. EDT on Monday, Aug. 29.

Students from Aviation High School, Puyallup High School, Civil Air Patrol and Liberty High School will ask Expedition 28 Flight Engineers Ron Garan, Mike Fossum and Satoshi Furukawa questions about life, work and research in space. The event will include a video link with the three astronauts and will be broadcast live on NASA Television.

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NASA’S Swift Satellite Spots Black Hole Devouring A Star

August 25, 2011 Leave a comment

Two studies appearing in the Aug. 25 issue of the journal Nature provide new insights into a cosmic accident that has been streaming X-rays toward Earth since late March. NASA’s Swift satellite first alerted astronomers to intense and unusual high-energy flares from the new source in the constellation Draco.

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New Ohio Park Protects Nighttime Environment

August 24, 2011 Leave a comment

An overcast sky in Geauga County, Ohio, did not dampen the enthusiasm of the 1,500 people attending Observatory Park’s dedication on 20 August, when it announced its full status as an International Dark Sky Park (IDSPark). The new park is the latest member of the growing IDSPlaces program, the flagship of the International Dark-Sky Association’s ongoing efforts to promote stewardship of the night sky.

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NASA Television To Air Space Station Cargo Ship Arrival

August 24, 2011 Leave a comment

NASA Television will provide live coverage as a Russian Progress cargo spacecraft arrives at the International Space Station at 9:38 a.m. CDT on Friday, Aug. 26.

NASA TV coverage will begin at 9 a.m. The unpiloted Progress 44 spacecraft will automatically dock to the rear port of the station’s Zvezda service module.

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NASA Hosts News Conference On Upcoming Mission To Moon

August 24, 2011 Leave a comment

NASA will host a news conference at 11 a.m. EDT, on Thursday Aug. 25, to discuss the upcoming launch of the Gravity Recovery And Interior Laboratory (GRAIL) mission.

Scheduled to launch Sept. 8, GRAIL will help answer longstanding questions about Earth’s moon and provide a better understanding of how Earth and other rocky planets in our solar system formed.

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LHC Experiments Present Latest Results in Mumbai

August 22, 2011 Leave a comment

Geneva, 22 August 2011. Results from the ATLAS and CMS collaborations, presented at the biennial Lepton-Photon conference in Mumbai, India today, show that the elusive Higgs particle, if it exists, is running out of places to hide. Proving or disproving the existence the Higgs boson, which was postulated in the 1960s as part of a mechanism that would confer mass on fundamental particles, is among the main goals of the LHC scientific programme. ATLAS and CMS have excluded the existence of a Higgs over most of the mass region 145 to 466 GeV with 95 percent certainty.

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