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Archive for April, 2013

Comet to Make Close Flyby of Red Planet in October 2014

Pasadena CA (JPL)

Apr 15, 2013

New observations of comet C/2013 A1 (Siding Spring) have allowed NASA’s Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif. to further refine the comet’s orbit.

Based on data through April 7, 2013, the latest orbital plot places the comet’s closest approach to Mars slightly closer than previous estimates, at about 68,000 miles (110,000 kilometers).

At the same time, the new data set now significantly reduces the probability the comet will impact the Red Planet, from about 1 in 8,000 to about 1 in 120,000.

The latest estimated time for close approach to Mars is about 11:51 a.m. PDT (18:51 UTC) on Oct. 19, 2014. At the time of closest approach, the comet will be on the sunward side of the planet…

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Comet_to_Make_Close_Flyby_of_Red_Planet_in_October_2014_999.html.

Where are the Best Windows Into Europa’s Interior?

Pasadena CA (JPL)

Apr 15, 2013

The surface of Jupiter’s moon Europa exposes material churned up from inside the moon and also material resulting from matter and energy coming from above. If you want to learn about the deep saltwater ocean beneath this unusual world’s icy shell — as many people do who are interested in possible extraterrestrial life — you might target your investigation of the surface somewhere that has more of the up-from-below stuff and less of the down-from-above stuff.

New analysis of observations made more than a decade ago by NASA’s Galileo mission to Jupiter helps identify those places.

“We have found the regions where charged electrons and ions striking the surface would have done the most, and the least, chemical processing of materials emplaced at the surface from the interior ocean,” said J. Brad Dalton of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the report published recently in the journal Planetary and Space Science.

“That tells us where to look for materials representing the most pristine ocean composition, which would be the best places to target with a lander or study with an orbiter.”

Europa is about the size of Earth’s moon and, like our moon, keeps the same side toward the planet it orbits. Picture a car driving in circles around a mountain with its left-side windows always facing the mountain.

Europa’s orbit around Jupiter is filled with charged, energetic particles tied to Jupiter’s powerful magnetic field. Besides electrons, these particles include ions of sulfur and oxygen originating from volcanic eruptions on Io, a neighboring moon.

The magnetic field carrying these energetic particles sweeps around Jupiter faster than Europa orbits Jupiter, in the same direction: about 10 hours per circuit for the magnetic field versus about 3.6 days for Europa’s orbit. So, instead of our mountain-circling car getting bugs on the front windshield, the bugs are plastered on the back of the car by a “wind” from behind going nearly nine times faster than the car. Europa has a “leading hemisphere” in front and a “trailing hemisphere” in back.

Earlier studies had found more sulfuric acid being produced toward the center of the trailing hemisphere than elsewhere on Europa’s surface, interpreted as resulting from chemistry driven by sulfur ions bombarding the icy surface.

Dalton and his co-authors at JPL and at Johns Hopkins University Applied Physics Laboratory, Laurel, Md., examined data from observations by Galileo’s near infrared mapping spectrometer of five widely distributed areas of Europa’s surface. The spectra of reflected light from frozen material on the surface enabled them to distinguish between relatively pristine water and sulfate hydrates.

These included magnesium and sodium sulfate salt hydrates, and hydrated sulfuric acid. They compared the distributions of these substances with models of how the influxes of energetic electrons and of sulfur and oxygen ions are distributed around the surface of Europa.

The concentration of frozen sulfuric acid on the surface varies greatly, they found. It ranges from undetectable levels near the center of the leading hemisphere, to more than half of the surface materials near the center of the heavily bombarded trailing hemisphere. The concentration was closely related to the amount of electrons and sulfur ions striking the surface.

“The close correlation of electron and ion fluxes with the sulfuric acid hydrate concentrations indicates that the surface chemistry is affected by these charged particles,” says Dalton.

“If you are interested in the composition and habitability of the interior ocean, the best places to study would be the parts of the leading hemisphere we have identified as receiving the fewest electrons and having the lowest sulfuric acid concentrations.”

Surface deposits in these areas are most likely to preserve the original chemical compounds that erupted from the interior. Dalton suggests that any future spacecraft missions to Europa should target these deposits for study from orbit, or even attempt to land there.

Dalton said, “The darkest material, on the trailing hemisphere, is probably the result of externally-driven chemical processing, with little of the original oceanic material intact.

While investigating the products of surface chemistry driven by charged particles is still interesting from a scientific standpoint, there is a strong push within the community to characterize the contents of the ocean and determine whether it could support life. These kinds of places just might be the windows that allow us to do that.”

The study was funded by NASA’s Outer Planets Research Program. NASA’s Galileo mission, launched in 1989, orbited Jupiter, investigating the planet and its diverse moons from 1995 to 2003. JPL, a division of the California Institute of Technology in Pasadena, managed Galileo for NASA’s Science Mission Directorate, Washington.

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Where_are_the_Best_Windows_Into_Europas_Interior_999.html.

Can One Buy the Right to Name a Planet?

Paris, France (SPX)

Apr 15, 2013

In the light of recent events, where the possibility of buying the rights to name exoplanets has been advertised, the International Astronomical Union (IAU) wishes to inform the public that such schemes have no bearing on the official naming process.

The IAU wholeheartedly welcomes the public’s interest to be involved in recent discoveries, but would like to strongly stress the importance of having a unified naming procedure.

More than 800 planets outside the Solar System have been found to date, with thousands more waiting to be confirmed. Detection methods in this field are steadily and quickly increasing – meaning that many more exoplanets will undoubtedly be discovered in the months and years to come.

Recently, an organisation has invited the public to purchase both nomination proposals for exoplanets, and rights to vote for the suggested names. In return, the purchaser receives a certificate commemorating the validity and credibility of the nomination.

Such certificates are misleading, as these campaigns have no bearing on the official naming process – they will not lead to an officially-recognized exoplanet name, despite the price paid or the number of votes accrued.

Upon discovery, exoplanets and other astronomical objects receive unambiguous and official catalogue designations. While exoplanet names such as 16 Cygni Bb or HD 41004 Ab may seem boring when considering the names of planets in our own Solar System, the vast number of objects in our Universe – galaxies, stars, and planets to name just a few – means that a clear and systematic system for naming these objects is vital.

Any naming system is a scientific issue that must also work across different languages and cultures in order to support collaborative worldwide research and avoid confusion.

To make this possible, the IAU acts as a single arbiter of the naming process, and is advised and supported by astronomers within different fields.

As an international scientific organisation, it dissociates itself entirely from the commercial practice of selling names of planets, stars or or even “real estate” on other planets or moons. These practices will not be recognized by the IAU and their alternative naming schemes cannot be adopted.

However, the IAU greatly appreciates and wishes to acknowledge the increasing interest from the general public in being more closely involved in the discovery and understanding of our Universe.

As a result in 2013 the IAU Commission 53 Extrasolar Planets and other IAU members will be consulted on the topic of having popular names for exoplanets, and the results will be made public on the IAU website.

Meanwhile, astronomers and the public are encouraged to keep using the existing accepted nomenclature – details of which can be found on the Astronomy for the Public section of the IAU web page, under Naming Astronomical Objects.

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Can_One_Buy_the_Right_to_Name_a_Planet_999.html.

Russia to Explore Moon, Mars by 2030

Blagoveshensk, Russia

(RIA Novosti) Apr 15, 2013

Russia will develop new technology including huge new rockets for manned flights to the Moon and Mars by 2030, Deputy Prime Minister Dmitry Rogozin said on Friday.

Rogozin, who oversees the space and military industries, said on Friday Russia is going to design a carrier rocket with a payload of 130 to 180 tons as well as powerful interplanetary vehicles.

The new technologies will lay the ground for manned flights to the Mars, Rogozin said.

Rogozin made his remarks while opening a meeting on the space industry in Russia’s Far East on Friday, as Russia marks the anniversary of Yury Gagarin’s first manned space flight on April 12, 1961.

Russia plans to start test of a new-generation spacecraft in the next two decades which could potentially be used for manned flights to the Moon, Rogozin said.

The Russian space industry is also set to develop a robot system for Moon exploration, as well as construct a permanent research base and a takeoff and landing pad there, he said.

The Soviet Union was developing a large rocket called the N-1 in the late 1960’s for a lunar landing, but the project was abandoned after the United States won the race to land on the moon in 1969.

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Russia_to_Explore_Moon_Mars_by_2030_999.html.

Green Pea galaxies could help astronomers understand early universe

Ann Arbor MI (SPX)

Apr 04, 2013

The rare Green Pea galaxies discovered by the general public in 2007 could help confirm astronomers’ understanding of reionization, a pivotal stage in the evolution of the early universe, say University of Michigan researchers.

Reionization occurred a few hundred million years after the Big Bang as the first stars were turning on and forming the first galaxies. During this period, the space between the galaxies changed from an opaque, neutral fog to a transparent charged plasma, as it is today. Plasma is gas that’s electrically charged.

As for how this happened, the prevailing theory holds that massive stars in the early galaxies produced an abundance of high-energy ultraviolet light that escaped into intergalactic space.

There, the UV light interacted with the neutral hydrogen gas it met, blasting electrons off the hydrogen atoms and leaving behind a plasma of negatively charged electrons and positively charged hydrogen ions.

“We think this is what happened but when we looked at galaxies nearby, the high-energy radiation doesn’t appear to make it out. There’s been a push to find some galaxies that show signs of radiation escaping,” said Anne Jaskot, a doctoral student in astronomy.

Jaskot and Sally Oey, an associate professor of astronomy in the College of Literature, Science, and the Arts, have found that the Green Peas could hold that evidence. Their findings are published in the current edition of the Astrophysical Journal.

“The Green Peas are compact, highly star-forming galaxies that are very similar to the early galaxies in the universe,” Jaskot said. “Our analysis shows they may be leaking ionizing radiation.”

The researchers focused on six of the most intensely star-forming Green Pea galaxies, which are between one billion and five billion light years away.

They studied their emission lines as observed by the Sloan Digital Sky Survey. Emission lines show how light interacts with matter, and in this case, they helped the astronomers understand the relationship between the stars and gas in these galaxies.

The emission lines told Jaskot and Oey how much light the galaxies absorbed. Then, to determine how much light was there to start with, they ran models to estimate, for example, how old the galaxies are and how many stars they contain.

The galaxies, the researchers determined, produced more radiation than the researchers detected, so they infer that some of it must have escaped.

“An analogy might be if you have a tablecloth and you spill something on it. If you see the cloth has been stained all the way to the edges, there’s a good chance it also spilled onto the floor,” Jaskot said.

“We’re looking at the gas like the tablecloth and seeing how much light it has absorbed. It has absorbed a lot of light. We’re seeing that the galaxy is saturated with it and there’s probably some extra that spilled off the edges.”

Jaskot says the Green Peas are exciting candidates to help astronomers understand a major milestone in the development of the cosmos 13 billion years ago.

The paper is called The Origin and Optical Depth of Ionizing Radiation in the ‘Green Pea’ Galaxies. The research is funded by the National Science Foundation.

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Green_Pea_galaxies_could_help_astronomers_understand_early_universe_999.html.

American charged, ex-general held in Venezuela

April 28, 2013

CARACAS, Venezuela (AP) — An American filmmaker was formally charged late Saturday by Venezuelan officials who accuse him of paying right-wing groups to foment postelection unrest on behalf of U.S. intelligence.

The federal prosecutor’s office said Timothy Tracy, 35, of West Hollywood, California, was charged with crimes including conspiracy, association for criminal purposes and use of a false document. On Thursday, President Nicolas Maduro said he had personally ordered Tracy’s arrest on suspicion of “creating violence in the cities of this country” in the wake of an April 14 presidential election narrowly won by the hand-picked successor to Hugo Chavez.

Opposition candidate Henrique Capriles contends the election was stolen from him by fraud, setting up postelection tensions and bitter accusations between Venezuela’s government and opposition. Friends say Tracy is an innocent, self-funded documentary filmmaker with no political aims or government ties.

The U.S. government has also said Tracy is innocent but declined comment on the specifics of his case. Venezuela’s national prosecutor’s office said a judge had ordered Tracy held until further notice in a jail run by the national intelligence service in the capital, Caracas, because he presented a risk of flight.

Tracy had a translator and private lawyers hired by him, or on his behalf, during the hearing, prosecutors said. The Georgetown University English graduate was a story consultant on the 2009 documentary “American Harmony,” about competitive barbershop quartet singing, and produced the recent Discovery Channel program “Under Siege,” about terrorism and smuggling across the U.S.-Canada border as well the History Channel series “Madhouse,” on modified race-car drivers in North Carolina.

Separately, Venezuelan officials said Saturday that they have arrested a retired general who had become a fierce critic of the government, a detention the opposition called part of a hardening crackdown in the wake of the disputed election.

Retired Brig. Gen. Antonio Rivero gained fame for denouncing Cuban involvement in the Venezuelan military in 2010 and became a prominent member of the opposition, participating in post-vote protests this month.

Rivero appeared in a brief video of a postelection protest that prosecutors played for the press Thursday after announcing Tracy’s arrest. They said the video was taken from Tracy’s belongings, along with another short video that shows a group of young people talking, in what appears to be a joking, sarcastic manner, about being paid many millions of dollars to participate in anti-government demonstrations.

In a snippet that is clearly heavily edited, Rivero discusses demonstrators’ use of clubs and rocks in a clash with National Guard members. It is unclear, because of the editing and brevity of the clip, whether he is encouraging them to use weapons or discouraging them.

The footage appeared to be taken at a protest in Caracas soon after the vote results were announced, in which university students and National Guard members traded rocks and tear gas. Leopoldo Lopez, national coordinator of the opposition Voluntad Popular party, called Rivero’s detention illegal and part of a campaign to arrest and “morally assassinate” Venezuela’s opposition leadership.

“The government errs if it thinks we are going to falter in our just solicitude that the truth be known about the April 14” election, Lopez said. Rivero is a member of Lopez’s party. Venezuela’s Public Ministry released a statement saying that Rivero would be presented before a tribunal “for his presumed connection to violent acts that have occurred recently in this country.”

The statement said the retired general was arrested by Venezuela’s intelligence service on Saturday. The government says postelection attacks by Capriles supporters killed nine members of the ruling Chavista movement, left dozens injured and damaged government offices and medical clinics.

The opposition vehemently denies the accusations.

Associated Press Writers Christopher Toothaker in Caracas contributed to this report.

Supernova remnant 1987A continues to reveal its secrets

Perth, Australia (SPX)

Apr 03, 2013

A team of astronomers led by the International Centre for Radio Astronomy Research (ICRAR) have succeeded in observing the death throws of a giant star in unprecedented detail

In February of 1987 astronomers observing the Large Magellanic Cloud, a nearby dwarf galaxy, noticed the sudden appearance of what looked like a new star. In fact they weren’t watching the beginnings of a star but the end of one and the brightest supernova seen from Earth in the four centuries since the telescope was invented.

By the next morning news of the discovery had spread across the globe and southern hemisphere stargazers began watching the aftermath of this enormous stellar explosion, known as a supernova.

In the two and a half decades since then, the remnant of Supernova 1987A has continued to be a focus for researchers around the world, providing a wealth of information about one of the Universe’s most extreme events.

In research published in the Astrophysical Journal a team of astronomers in Australia and Hong Kong have succeeded in using the Australia Telescope Compact Array, CSIRO radio telescope in northern New South Wales, to make the highest resolution radio images of the expanding supernova remnant at millimeter wavelengths.

“Imaging distant astronomical objects like this at wavelengths less than 1 centimeter demands the most stable atmospheric conditions. For this telescope these are usually only possible during cooler winter conditions but even then, the humidity and low elevation of the site makes things very challenging,” said lead author, Dr Giovanna Zanardo of ICRAR, a joint venture of Curtin University and The University of Western Australia in Perth.

Unlike optical telescopes, a radio telescope can operate in the daytime and can peer through gas and dust allowing astronomers to see the inner workings of objects like supernova remnants, radio galaxies and black holes.

“Supernova remnants are like natural particle accelerators, the radio emission we observe comes from electrons spiraling along the magnetic field lines and emitting photons every time they turn. The higher the resolution of the images the more we can learn about the structure of this object,” said Professor Lister Staveley-Smith, Deputy Director of ICRAR and CAASTRO, the Center for All-sky Astrophysics.

Scientists study the evolution of supernovae into supernova remnants to gain an insight into the dynamics of these massive explosions and the interaction of the blast wave with the surrounding medium.

“Not only have we been able to analyse the morphology of Supernova 1987A through our high resolution imaging, we have compared it to X-ray and optical data in order to model its likely history,” said Professor Bryan Gaensler, Director of CAASTRO at the University of Sydney.

The team suspects a compact source or pulsar wind nebula to be sitting in the center of the radio emission, implying that the supernova explosion did not make the star collapse into a black hole. They will now attempt to observe further into the core and see what’s there.

Source: Space Daily.

Link: http://www.spacedaily.com/reports/Supernova_remnant_1987A_continues_to_reveal_its_secrets_999.html.

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