samedi 3 novembre 2012

Scientists Monitor Comet Breakup











Asteroid and comet watch.

Nov. 3, 2012


Comet 168P-Hergenrother was imaged by the NOAO/Gemini telescope on Nov. 2, 2011 at about 6 a.m. UTC. Image credit: NASA/JPL-Caltech/NOAO/Gemini.

 The Hergenrother comet is currently traversing the inner-solar system. Amateur and professional astronomers alike have been following the icy-dirt ball over the past several weeks as it has been generating a series of impressive outbursts of cometary-dust material. Now comes word that the comet's nucleus has taken the next step in its relationship with Mother Nature.

"Comet Hergenrother is splitting apart," said Rachel Stevenson, a post-doctoral fellow working at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Using the National Optical Astronomy Observatory's Gemini North Telescope on top of Mauna Kea, Hawaii, we have resolved that the nucleus of the comet has separated into at least four distinct pieces resulting in a large increase in dust material in its coma."

With more material to reflect the sun's rays, the comet's coma has brightened considerably.

"The comet fragments are considerably fainter than the nucleus," said James Bauer, the deputy principal investigator for NASA's NEOWISE mission, from the California Institute of Technology. "This is suggestive of chunks of material being ejected from the surface."

For those interested in viewing Hergenrother, with a larger-sized telescope and a dark sky, the comet can be seen in between the constellations of Andromeda and Lacerta.

The orbit of comet 168P/Hergenrother comet is well understood. The comet, nor any of its fragments, are a threat to Earth.

Splitting event in Comet 168P/Hergenrother

Stacking of 26 R-filtered exposures, 35-sec each, obtained remotely, from the Haleakala-Faulkes Telescope North on 2012, Nov. 2.4, through a 2.0-m f/10.0 Ritchey-Chretien + CCD, under good seeing conditions, confirms the presence of a secondary nucleus, or fragment, now placed about 3.3" in PA 165 with respect to the main central condensation of comet 168P. This fragment is now fainter, compared to our previous Oct. 26.4 detection, having R magnitude about 18.7; its diameter is still about 2", but now it appears more diffuse, without a clear central condensation (this hampers a precise determination of its photocenter). This fragment appears to have developed its own tail, nearly 4" long in PA 113 (about parallel to the main tail originating from the central condensation of 168P).

Below you can see our rendition of yesterday imaging session. Through some image processing, the tail of the fragment became easily visible.


Another rendition of the same image is shown below.


Related links:
Faulkes Telescope Education project: http://www.faulkes-telescope.com/

Remanzacco Observatory: http://remanzacco.blogspot.ch/

Images, Text, Credits: NASA / JPL-Caltech / DC Agle / NOAO / Gemini /  Remanzacco Observatory / Giovanni Sostero, Nick Howes & Ernesto Guido.

Greetings, Orbiter.ch

NASA Rover Finds Clues to Changes in Mars' Atmosphere












NASA - Mars Science Laboratory (MSL) patch.

Nov. 3, 2012


This picture shows a lab demonstration of the measurement chamber inside the Tunable Laser Spectrometer, an instrument that is part of the Sample Analysis at Mars investigation on NASA's Curiosity rover. Image Credit: NASA/JPL-Caltech.

NASA's car-sized rover, Curiosity, has taken significant steps toward understanding how Mars may have lost much of its original atmosphere.

Learning what happened to the Martian atmosphere will help scientists assess whether the planet ever was habitable. The present atmosphere of Mars is 100 times thinner than Earth's.

A set of instruments aboard the rover has ingested and analyzed samples of the atmosphere collected near the "Rocknest" site in Gale Crater where the rover is stopped for research. Findings from the Sample Analysis at Mars (SAM) instruments suggest that loss of a fraction of the atmosphere, resulting from a physical process favoring retention of heavier isotopes of certain elements, has been a significant factor in the evolution of the planet. Isotopes are variants of the same element with different atomic weights.

Initial SAM results show an increase of five percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed. These enriched ratios of heavier isotopes to lighter ones suggest the top of the atmosphere may have been lost to interplanetary space. Losses at the top of the atmosphere would deplete lighter isotopes. Isotopes of argon also show enrichment of the heavy isotope, matching previous estimates of atmosphere composition derived from studies of Martian meteorites on Earth.


This graph shows the percentage abundance of five gases in the atmosphere of Mars, as measured by the Quadrupole Mass Spectrometer instrument of the Sample Analysis at Mars instrument suite on NASA's Mars rover in October 2012. Image Credit: NASA/JPL-Caltech, SAM/GSFC.

Scientists theorize that in Mars' distant past its environment may have been quite different, with persistent water and a thicker atmosphere. NASA's Mars Atmosphere and Volatile Evolution, or MAVEN, mission will investigate possible losses from the upper atmosphere when it arrives at Mars in 2014.

With these initial sniffs of Martian atmosphere, SAM also made the most sensitive measurements ever to search for methane gas on Mars. Preliminary results reveal little to no methane. Methane is of interest as a simple precursor chemical for life. On Earth, it can be produced by either biological or non-biological processes.

Methane has been difficult to detect from Earth or the current generation of Mars orbiters because the gas exists on Mars only in traces, if at all. The Tunable Laser Spectrometer (TLS) in SAM provides the first search conducted within the Martian atmosphere for this molecule. The initial SAM measurements place an upper limit of just a few parts methane per billion parts of Martian atmosphere, by volume, with enough uncertainty that the amount could be zero.

"Methane is clearly not an abundant gas at the Gale Crater site, if it is there at all. At this point in the mission we're just excited to be searching for it," said SAM TLS lead Chris Webster of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "While we determine upper limits on low values, atmospheric variability in the Martian atmosphere could yet hold surprises for us."

video
First CheMin Results

Video above: NASA's Curiosity rover gets its first taste of Mars and finds minerals: plagioclase feldspar, pyroxene and olivine. Credit: NASA/JPL-Caltech.

In Curiosity's first three months on Mars, SAM has analyzed atmosphere samples with two laboratory methods. One is a mass spectrometer investigating the full range of atmospheric gases. The other, TLS, has focused on carbon dioxide and methane. During its two-year prime mission, the rover also will use an instrument called a gas chromatograph that separates and identifies gases. The instrument also will analyze samples of soil and rock, as well as more atmosphere samples.

"With these first atmospheric measurements we already can see the power of having a complex chemical laboratory like SAM on the surface of Mars," said SAM Principal Investigator Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Md. "Both atmospheric and solid sample analyses are crucial for understanding Mars' habitability."

Curiosity Instruments Description. Credit: NASA/JPL-Caltech

SAM is set to analyze its first solid sample in the coming weeks, beginning the search for organic compounds in the rocks and soils of Gale Crater. Analyzing water-bearing minerals and searching for and analyzing carbonates are high priorities for upcoming SAM solid sample analyses.

Researchers are using Curiosity's 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate, Washington, and built Curiosity. The SAM instrument was developed at Goddard with instrument contributions from Goddard, JPL and the University of Paris in France.

For more information about Curiosity and its mission, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

Curiosity gallery: http://www.nasa.gov/mission_pages/msl/multimedia/gallery-indexEvents.html

Images (mentioned), Video (mnetioned), Text, Credits: NASA / Dwayne Brown / NASA Goddard Space Flight Center / Jet Propulsion Laboratory / Guy Webster.

Best regards, Orbiter.ch

vendredi 2 novembre 2012

Proton lifts off with Russian communications satellites












ROSCOSMOS logo.

Nov. 2, 2012

 Proton-M launch

A Russian Proton-M rocket launched today, November 2nd 2012 at 21:04 UTC with two communications satellites, Luch-5B and Yamal-300K. Lift off occurred from Baikonur in Kazachstan.

video
Proton-M Launch of Luch-5B & Yamal-300K

Luch-5B is a S-band and Ku-band relay satellite that will receive signals from low flying satellites, such as the International Space Station, and relay the signals to ground stations on Earth. Yamal-300K is a C-band and Ku-band satellite that will transmit Television and Internet to Russia.

Luch-5B satellite

Yamal-300K satellite

For more information about ROSCOSMOS, visit: http://www.federalspace.ru/

Images, Video, Text, Credits: ROSCOSMOS / Roscosmos TV / ISS Reshetnev / Orbiter.ch.

Cheers, Orbiter.ch

CERN - What else could this boson be?












CERN - European Organization for Nuclear Research logo.

2 November 2012

On 4 July 2012 the ATLAS and CMS experiments at CERN presented their latest preliminary results in the search for the long-sought Higgs particle. Both experiments observed a new particle in the mass region around 125-126 GeV.


The next step is to determine the precise nature of the particle and its significance for our understanding of the universe. Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? Symmetry has more on what this Higgs-like particle could be.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

Read more:

Symmetry - "What else could the Higgs be?": http://www.symmetrymagazine.org/article/october-2012/what-else-could-the-higgs-be

CERN related article: http://press.web.cern.ch/press-releases/2012/07/cern-experiments-observe-particle-consistent-long-sought-higgs-boson

For more information about the CERN, visit: http://public.web.cern.ch/public/Welcome.html

Image, Text, Credits: CERN / Graphic NEWS.

Greetings, Orbiter.ch

jeudi 1 novembre 2012

Station Spacewalk Today; Debris Avoidance Maneuver Completed Thursday












ISS - Expedition 33 Mission patch.

Nov. 1, 2012

Expedition 33 Commander Suni Williams and Flight Engineer Aki Hoshide switched their spacesuits to battery power at 8:29 a.m. EDT, signalling the start of Thursday’s planned 6.5-hour excursion outside the International Space Station. 

During the spacewalk, Williams and Hoshide are venturing out to the port side of the station’s truss to configure the 2B solar array power channel’s photovoltaic thermal control system (PVTCS) to support ground-based troubleshooting of an ammonia leak.


Image above: Astronaut Aki Hoshide participates in Thursday's spacewalk outside the International Space Station. Credit: NASA TV.

The spacewalking duo will isolate the photovoltaic radiator on the P6 truss from the PVTCS, shutting off the flow of ammonia in and out of it and rerouting the ammonia flow through a spare radiator so the PVTCS can continue operation. Over the following weeks and months, flight controllers at Mission Control Houston will monitor telemetry to see if the leak continues.

If rerouting the ammonia through the spare radiator stops the leak, mission managers will evaluate whether to leave the fix as-is or replace the photovoltaic radiator on a future spacewalk. If the leak continues, additional troubleshooting will be required.


Image above: Commander Suni Williams (right) and Flight Engineer Aki Hoshide participate in Thursday's spacewalk outside the International Space Station Credit: NASA TV.

Williams, who is the lead for this spacewalk, is wearing the suit with red stripes. This is the seventh spacewalk for Williams who holds the record for spacewalking time for female astronauts with over 44 hours during six previous excursions. Hoshide, who is making his third spacewalk, now holds the equivalent record for Japanese astronauts.

This is the 166th spacewalk in support of International Space Station assembly and maintenance and the 138th spacewalk from the station.


Image above: Expedition 33 Astronaut works outside the space station during a November 1 spacewalk.

Last night, thrusters on the ISS Progress 48 cargo ship at the Pirs Docking Compartment were used to raise the station’s altitude in a debris avoidance maneuver to steer clear of a small fragment of debris from the Iridium 33 satellite. Only one set of thrusters on a single manifold was used to execute the reboost at 6:08 p.m. CDT instead of the planned both sets of thrusters on two manifolds, resulting in a slightly reduced altitude change. The single manifold selection was the result of a software configuration, but the burn lasted 10 minutes in duration and was automatically terminated by thruster cut off limits.

Despite the fact that the maneuver achieved only about 72 percent of the planned altitude change, the goal of maneuvering away from the debris was accomplished and no additional maneuver is required.

The reboost increased the station’s altitude by 0.18 statute miles at apogee and 0.49 statute miles at perigee. The station is now orbiting at an altitude of 261.3 x 252.3 statute miles.

Follow @Astro_Suni on Twitter: http://twitter.com/Astro_Suni

Visit Gateway to Astronaut Photography of Earth: http://eol.jsc.nasa.gov/

Read more about Expedition 33: http://www.nasa.gov/mission_pages/station/expeditions/expedition33/index.html

For information on the International Space Station (ISS), visit: http://www.nasa.gov/station

Images, Text, Credit: NASA / NASA TV.

Greetings, Orbiter.ch

Dawn Sees "Young" Surface on Giant Asteroid












NASA - Dawn Mission patch.

Nov. 1, 2012


This image from NASA's Dawn spacecraft shows a close up of part of the rim around the crater Canuleia on the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI/Brown.

 Like a Hollywood starlet constantly retouching her makeup, the giant asteroid Vesta is constantly stirring its outermost layer to present a young face. Data from NASA's Dawn mission show that a form of weathering that occurs on the moon and other airless bodies we've visited in the inner solar system does not alter Vesta's outermost layer in the same way. Carbon-rich asteroids have also been splattering dark material on Vesta's surface over a long span of the body's history. The results are described in two papers released today in the journal Nature.

"Dawn's data allow us to decipher how Vesta records fundamental processes that have also affected Earth and other solar system bodies," said Carol Raymond, Dawn deputy principal investigator at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "No object in our solar system is an island. Throughout solar system history, materials have exchanged and interacted."

Over time, soils on Earth's moon and asteroids such as Itokawa have undergone extensive weathering in the space environment. Scientists see this in the accumulation of tiny metallic particles containing iron, which dulls the fluffy outer layer. Dawn's visible and infrared mapping spectrometer (VIR) and framing camera detected no accumulation of such tiny particles on Vesta, and this particular protoplanet, or almost-planet, remains bright and pristine.


Image above: Canuleia, about 6 miles (10 kilometers) in diameter, is distinguished by the rays of bright material that streak out from it. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI/Brown.

Nevertheless, the bright rays of the youngest features on Vesta are seen to degrade rapidly and disappear into background soil. Scientists know frequent, small impacts continually mix the fluffy outer layer of broken debris. Vesta also has unusually steep topography relative to other large bodies in the inner solar system, which leads to landslides that further mix surface material.

"Getting up close and familiar with Vesta has reset our thinking about the character of the uppermost soils of airless bodies," said Carle Pieters, one of the lead authors and a Dawn team member based at Brown University, Providence, R.I. "Vesta 'dirt' is very clean, well mixed and highly mobile."

Early pictures of Vesta showed a variety of dramatic light and dark splotches on Vesta's surface. These light and dark materials were unexpected and now show the brightness range of Vesta is among the largest observed on rocky bodies in our solar system.

Dawn scientists suspected early on that bright material is native to Vesta. One of their first hypotheses for the dark material suggested it might come from the shock of high-speed impacts melting and darkening the underlying rocks or from recent volcanic activity. An analysis of data from VIR and the framing camera has revealed, however, that the distribution of dark material is widespread and occurs both in small spots and in diffuse deposits, without correlation to any particular underlying geology. The likely source of the dark material is now shown to be the carbon-rich material in meteoroids, which are also believed to have deposited hydrated minerals from other asteroids on Vesta.


Image above: The interplay of bright and dark material at the rim of Marcia crater on Vesta is visible in this image mosaic taken by NASA's Dawn spacecraft. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/LPI/ASU.

To get the amount of darkening we now see on Vesta, scientists on the Dawn team estimate about 300 dark asteroids with diameters between 0.6 to 6 miles (1 and 10 kilometers) likely hit Vesta during the last 3.5 billion years. This would have been enough to wrap Vesta in a blanket of mixed material about 3 to 7 feet (1 to 2 meters) thick.

"This perpetual contamination of Vesta with material native to elsewhere in the solar system is a dramatic example of an apparently common process that changes many solar system objects," said Tom McCord, the other lead author and a Dawn team member based at the Bear Fight Institute, Winthrop, Wash. "Earth likely got the ingredients for life - organics and water - this way."

Launched in 2007, Dawn spent more than a year investigating Vesta. It departed in September 2012 and is currently on its way to the dwarf planet Ceres.


Image above: Artist concept showing the Dawn spacecraft with Ceres and Vesta. Image credit: William K. Hartmann Courtesy of UCLA.

JPL manages the Dawn mission for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. The University of California at Los Angeles (UCLA) is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.

For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .

Image (mentioned), Text, Credits: NASA / Jet Propulsion Laboratory (JPL) / Jia-Rui Cook.

Cheers, Orbiter.ch

NASA'S Fermi Measures Cosmic 'Fog' Produced by Ancient Starlight











NASA - Fermi Gamma-ray Space Telescope logo.

Nov. 1, 2012

Astronomers using data from NASA's Fermi Gamma-ray Space Telescope have made the most accurate measurement of starlight in the universe and used it to establish the total amount of light from all of the stars that have ever shone, accomplishing a primary mission goal.

"The optical and ultraviolet light from stars continues to travel throughout the universe even after the stars cease to shine, and this creates a fossil radiation field we can explore using gamma rays from distant sources," said lead scientist Marco Ajello, a postdoctoral researcher at the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in California and the Space Sciences Laboratory at the University of California at Berkeley.

video

Video above: This animation tracks several gamma rays through space and time, from their emission in the jet of a distant blazar to their arrival in Fermi's Large Area Telescope (LAT). During their journey, the number of randomly moving ultraviolet and optical photons (blue) increases as more and more stars are born in the universe. Eventually, one of the gamma rays encounters a photon of starlight and the gamma ray transforms into an electron and a positron. The remaining gamma-ray photons arrive at Fermi, interact with tungsten plates in the LAT, and produce the electrons and positrons whose paths through the detector allows astronomers to backtrack the gamma rays to their source. (Credit: NASA's Goddard Space Flight Center/Cruz deWilde).

Gamma rays are the most energetic form of light. Since Fermi's launch in 2008, its Large Area Telescope (LAT) observes the entire sky in high-energy gamma rays every three hours, creating the most detailed map of the universe ever known at these energies.

Fermi Gamma-ray Space Telescope. Credit NASA

The total sum of starlight in the cosmos is known to astronomers as the extragalactic background light (EBL). To gamma rays, the EBL functions as a kind of cosmic fog. Ajello and his team investigated the EBL by studying gamma rays from 150 blazars, or galaxies powered by black holes, that were strongly detected at energies greater than 3 billion electron volts (GeV), or more than a billion times the energy of visible light.

"With more than a thousand detected so far, blazars are the most common sources detected by Fermi, but gamma rays at these energies are few and far between, which is why it took four years of data to make this analysis," said team member Justin Finke, an astrophysicist at the Naval Research Laboratory in Washington.


Image above: This plot shows the locations of 150 blazars (green dots) used in the EBL study. The background map shows the entire sky and was constructed from four years of gamma rays with energies above 10 billion electron volts (GeV) detected by Fermi. The plane of our Milky Way galaxy runs along the middle of the plot. The Fermi LAT instrument is the first to detect more than 500 sources in this energy range. (Credit: NASA/DOE/Fermi LAT Collaboration).

As matter falls toward a galaxy's supermassive black hole, some of it is accelerated outward at almost the speed of light in jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, the galaxy appears especially bright and is classified as a blazar.

Gamma rays produced in blazar jets travel across billions of light-years to Earth. During their journey, the gamma rays pass through an increasing fog of visible and ultraviolet light emitted by stars that formed throughout the history of the universe.

Occasionally, a gamma ray collides with starlight and transforms into a pair of particles -- an electron and its antimatter counterpart, a positron. Once this occurs, the gamma ray light is lost. In effect, the process dampens the gamma ray signal in much the same way as fog dims a distant lighthouse.

From studies of nearby blazars, scientists have determined how many gamma rays should be emitted at different energies. More distant blazars show fewer gamma rays at higher energies -- especially above 25 GeV -- thanks to absorption by the cosmic fog.


Graphic above: Fermi measured the amount of gamma-ray absorption in blazar spectra produced by ultraviolet and visible starlight at three different epochs in the history of the universe. (Credit: NASA's Goddard Space Flight Center).

The farthest blazars are missing most of their higher-energy gamma rays.

The researchers then determined the average gamma-ray attenuation across three distance ranges between 9.6 billion years ago and today.

From this measurement, the scientists were able to estimate the fog's thickness. To account for the observations, the average stellar density in the cosmos is about 1.4 stars per 100 billion cubic light-years, which means the average distance between stars in the universe is about 4,150 light-years.

A paper describing the findings was published Thursday on Science Express.

"The Fermi result opens up the exciting possibility of constraining the earliest period of cosmic star formation, thus setting the stage for NASA's James Webb Space Telescope," said Volker Bromm, an astronomer at the University of Texas, Austin, who commented on the findings. "In simple terms, Fermi is providing us with a shadow image of the first stars, whereas Webb will directly detect them."


This illustration places the Fermi measurements in perspective with other well-known features of cosmic history. Star formation reached a peak when the universe was about 3 billion years old and has been declining ever since. (Credit: NASA's Goddard Space Flight Center).

Measuring the extragalactic background light was one of the primary mission goals for Fermi.

"We're very excited about the prospect of extending this measurement even farther," said Julie McEnery, the mission's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

Goddard manages the Fermi astrophysics and particle physics research partnership. Fermi was developed in collaboration with the U.S. Department of Energy with contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

Press briefing multimedia associated with this story: http://www.nasa.gov/mission_pages/GLAST/news/cosmic-fog-briefing.html

For more information about NASA's Fermi Gamma-Ray Space Telescope, visit: http://www.nasa.gov/mission_pages/GLAST/main/index.html

Images (mentioned), Video (mentioned), Text, Credit: NASA's Goddard Space Flight Center / Francis Reddy.

Best regards, Orbiter.ch

NASA's SAMPEX Mission: A Space Weather Warrior










NASA - SAMPEX Mission patch.

Nov. 1, 2012


Image above: An artist's rendition of the Solar, Anomalous, and Magnetospheric Particle Explorer or SAMPEX. Credit: NASA.

NASA's very first small explorer, the Solar, Anomalous, and Magnetospheric Particle Explorer or SAMPEX, was launched July 3, 1992 to study the zoo of particles and cosmic rays surrounding Earth. Surviving much longer than its expected mission of three years and providing invaluable observations for those who study space weather, the SAMPEX mission is now almost over. In early November, the spacecraft's orbit will decay enough that it will re-enter Earth's atmosphere, burning up completely on re-entry.

When SAMPEX launched, the sun was just finishing the peak of its 11-year solar cycle and beginning to move toward solar minimum. Scientists were eager to watch what happened in near-Earth space in those first few years, as eruptions on the sun shot out energy and solar material and eventually tapered down into a period of quiet. However, those same effects were also predicted to lead to the spacecraft's demise. As the sun once again ramped up to solar maximum around 2000, the sun's output would create enough atmospheric drag that SAMPEX was expected to tumble out of its stable orbit.

Contrary to such predictions, SAMPEX is still in orbit having survived that maximum and continuing in orbit long enough to see the sun move toward another solar max, currently predicted for 2013. But time is running out. As the atmosphere near Earth heats and swells in response to the sun's activity, the expansion of the uppermost atmosphere has encased SAMPEX, slowing it down. Soon the 20-year-old spacecraft will succumb to the very space weather it has helped scientists to study. Some time at the end of 2012, the orbit of the five-by-three-foot craft will spiral far enough in that SAMPEX will re-enter Earth's atmosphere, burning up completely and disappearing forever.

"SAMPEX was launched on a shoe string budget," says Shri Kanekal, a space weather scientist at NASA's Goddard Space Weather Center in Greenbelt, Md. who has been involved with SAMPEX research since its launch. "It was proposed as a minimum one-year mission with a goal of three years, but it lasted for an unexpectedly long time. It has provided 20 years of high quality data, used by nearly everyone who studies near-Earth space."

In its two decades, SAMPEX provided one of the main sources of data on how the radiation environment around Earth changed over time, waxing and waning in response to incoming particles from the sun and galaxy. SAMPEX confirmed earlier theories that cosmic rays streaming in from outer space were being trapped in Earth's own magnetic environment, the magnetosphere, and it helped pinpoint the location where they gathered in a belt around Earth. Another area of research has been to tease out the composition of various particle populations from high-speed and high-energy particles from the sun known as solar energetic particles, to the host of electrons in Earth's middle atmosphere.

Also, SAMPEX has been one of our best eyes on the radiation belts – two giant donuts of radiation surrounding Earth that can affect satellites in orbit during their occasional bouts of swelling. Indeed, scientists are eager for SAMPEX data still, eking out the last weeks of observation time to compare with early data from the Radiation Belt Storm Probes (RBSP) mission that launched in August, 2012.


Image above: SAMPEX data have provided some of the most useful observations of the Van Allen Belts -- two rings of radiation around Earth. This SAMPEX data shows the belts during what's known as the Halloween Storms in October 2003, a time when the radiation belts around Earth swelled so much that they merged into a single ring. Credit: NASA/Goddard Space Flight Center .

When those who study the radiation belts realized how imminent was the demise of SAMPEX, they adjusted the schedule to turn on a SAMPEX-compatible instrument aboard RBSP, an instrument called Relativistic Electron Proton Telescope (REPT), earlier than planned. One of the space phenomena that SAMPEX has helped categorize is something called microbursts, an intense but short lived phase during which electrons drop out of the radiation belts. From its viewpoint under the radiation belts, SAMPEX can still record such microbursts. As part of RBSP, on the other hand, REPT can look at the electron population while traveling through the radiation belts proper. In combination, the data may help show what occurrences in the radiation belts correlate to the rain of electrons, the microbursts.

"Since one of the main goals of RBSP is to understand why and how electrons rain down out of the radiation belts, this will be important science," says Kanekal. "It's made all the more impressive that we can do this kind of research despite the fact that SAMPEX's science mission officially ended in 2004."

Although the spacecraft has remained in orbit, the official SAMPEX science mission ended in June 2004. New data remained available, however, thanks to The Aerospace Corporation of El Segundo, Calif., which continued to fund costs to download data, and to Bowie State University in Bowie, Md., which operated the spacecraft to maintain the download process as an educational tool for its students. Kanekal was also instrumental in getting a grant to process all the data from 2004 to 2012, so it will be usable by the science community.

NASA's first small explorer had an impressive run, far outliving its planned three-year mission. It provided data crucial to understanding how the space around Earth responds to space weather from the sun and will continue to do so up until the moment it re-enters Earth's atmosphere, disappearing forever.

NASA's SAMPEX Mission: http://science.nasa.gov/missions/sampex/

The SAMPEX Data Center: http://www.srl.caltech.edu/sampex/DataCenter/

Images (mentioned), Text, Credit: NASA Goddard Space Flight Center / Karen C. Fox.

Greetings, Orbiter.ch

Nereidum Montes helps unlock Mars’ glacial past












ESA - Mars Express Mission patch.

1 November 2012

(Click on the images for enlarge)

 Nereidum Montes

On 6 June, the high-resolution stereo camera on ESA’s Mars Express revisited the Argyre basin as featured in our October release, but this time aiming at Nereidum Montes, some 380 km northeast of Hooke crater.

The stunning rugged terrain of Nereidum Montes marks the far northern extent of Argyre, one of the largest impact basins on Mars.

Nereidum Montes stretches almost 1150 km and was named by the noted Greek astronomer Eugène Michel Antoniadi (1870–1944).

Based on his extensive observations of Mars, Antoniadi famously concluded that the ‘canals’ on Mars reported by Percival Lowell were, in fact, just an optical illusion. 

Nereidum Montes perspective view

The images captured by Mars Express show a portion of the region, displaying multiple fluvial, glacial and wind-driven features.

Extensive dendritic drainage patterns, seen towards the north (lower right side) of the first and topographic images, were formed when liquid water drained into deeper regions within the area.

On Earth, tree-like channels of this kind are usually formed by surface runoff after significant rainfall, or when snow or ice melts. Similar processes are thought to have occurred on Mars in the distant past, when scientists now know there to have been water on the surface of the Red Planet.

Several of the craters within the region, particularly in eastern parts (lower section) of the first image, show concentric crater fill, a distinctive martian process marked by rings of surface fluctuations within a crater rim.

The ratios between the diameter and depth of the filled craters suggest that there may still be water ice, possibly in the form of ancient glaciers, present below the dry surface debris cover.

Nereidum Montes in context

Scientists have estimated that the water-ice depth in these craters varies from several tens up to hundreds of metres.

The largest crater on the south western side (top-left half) of the first and topographic images appears to have spilled out a glacier-like formation towards lower-lying parts of the region (shown as blue in the topographic image).

Topographical view

A smooth area to the east of (below) the glacial feature appears to be the youngest within the image, evidenced by an almost complete lack of cratering.

Another indication of subsurface water is seen in the fluidised ejecta blanket surrounding the crater at the northern edge (right-hand side) of the first and topographic images.

These ejecta structures can develop when a comet or asteroid hits a surface saturated with water or water ice.

Perspective view

Finally, throughout the images and often near the wind-sheltered sides of mounds and canyons, extensive rippling sand dune fields are seen to have formed.

3D view

In-depth studies of regions such as Nereidum Montes play an essential role in unlocking the geological past of our terrestrial neighbour, as well as helping to find exciting regions for future robotic and human explorers to visit.

Related links:

Mars Express: http://www.esa.int/SPECIALS/Mars_Express/index.html

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens: http://www.esa.int/SPECIALS/Mars_Express/SEMSXE1PGQD_0.html

Frequently asked questions: http://www.esa.int/SPECIALS/Mars_Express/SEM76D9OY2F_0.html

Images, Text, Credits: Credits: ESA / DLR / FU Berlin (G. Neukum) / NASA MGS MOLA Science Team.

Greetings, Orbiter.ch

mercredi 31 octobre 2012

Progress M-17M docked at the Station











ROSCOSMOS - Russian Vehicles patch.

Oct. 31, 2012

Traveling about 250 miles above Bogota, Colombia, the Progress 49 Russian cargo ship docked at 9:33 a.m. EDT to the Russian Segment (RS) of the International Space Station (at 17:33.46 Moscow time).

Progress-M cargo spacecraft approaching the Station

The craft is delivering almost 3 tons of supplies -- including propellant, oxygen, water, air, spare parts and experimental hardware -- to the six crew members on the orbital laboratory. Progress 49 is scheduled to remain docked to the space station until mid-April.

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Docking of Progress M-17M to ISS

A Progress resupply spacecraft performed a same-day rendezvous and docking to the International Space Station for the second time. Progress 48 and 49 verified an abbreviated launch-to-rendezvous schedule designed to reduce the typical two-day flight between a launch and docking. The data may be applied for a similar single-day operation for manned Soyuz missions to the station beginning in 2013.

Docking location at the ISS on the Russian Orbital Segment

Currently, the International Space Station crew works 33/34-y long expedition consisting of commander Sanita Williams (NASA), the flight engineer Yuri Malenchenko (Roscosmos), Akihiko Hoshide (JAXA), Oleg Novitsky (Roscosmos), Eugene Tarelkin (Roscosmos) Kevin Ford (NASA).

For information on the International Space Station and the Expedition 33/34 crew, visit: http://www.nasa.gov/station

Report of Press Service of the Russian Federal Space Agency (Roscosmos PAO): http://www.federalspace.ru/main.php?id=2&nid=19655

Press Service of the Russian Federal Space Agency (Roscosmos PAO) / NASA / NASA TV / Translation: Orbiter.ch.

Greetings, Orbiter.ch

Stars Ancient and Modern?












ESO - European Southern Observatory logo.

31 October 2012

 The globular star cluster NGC 6362

This colourful view of the globular star cluster NGC 6362 was captured by the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. This new picture, along with a new image of the central region from the NASA/ESA Hubble Space Telescope, provide the best view of this little-known cluster ever obtained. Globular clusters are mainly composed of tens of thousands of very ancient stars, but they also contain some stars that look suspiciously young.

The globular star cluster NGC 6362 in the constellation of Ara (The Altar)

Globular star clusters are among the oldest objects in the Universe, and NGC 6362 cannot hide its age in this picture. The many yellowish stars in the cluster have already run through much of their lives and become red giant stars. But globular clusters are not static relics from the past —  some curious stellar activities are still going on in these dense star cities.

Wide-field view of the sky around the globular cluster NGC 6362

For instance, NGC 6362 is home to many blue stragglers — old stars that really do succeed in passing for a younger age. All of the stars in a globular cluster formed over a fairly short period of time, typically about 10 billion years ago for most globulars. Yet blue stragglers are bluer and more luminous — and hence more massive — than they should be after ten billion years of stellar evolution. Blue stars are hot and consume their fuel quickly, so if these stars had formed about ten billion years ago, then they should have fizzled out long ago. How did they survive?

Hubble image of the globular star cluster NGC 6362

Astronomers are keen to understand the secret of the youthful appearance of blue stragglers. Currently, there are two main theories: stars colliding and merging, and a transfer of material between two companion stars. The basic idea behind both of these options is that the stars were not born as big as we see them today, but that they received an injection of extra material at some point during their lifetimes and this then gave them a new lease of life.

Comparison of views of the globular star cluster NGC 6362 from WFI and Hubble

Although less well known than some brighter globular clusters, NGC 6362 holds much that is of interest to astronomers and has been well studied over the years. It was selected as one of the 160 stellar fields for the Pre-FLAMES Survey — a preliminary survey conducted between 1999 and 2002 using the 2.2-metre telescope at La Silla to find suitable stars for follow-up observations with the VLT’s spectroscopic instrument FLAMES. The picture here comes from data collected as part of this survey.

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Zooming in on the globular star cluster NGC 6362

The new image shows the entire cluster against a rich background of the carpet of stars in the Milky Way. The central parts of NGC 6362 have also been studied in detail by the NASA/ESA Hubble Space Telescope. The Hubble view shows a much smaller area of sky in much greater detail. The two views — one wide-angle and one zoomed in — complement each other perfectly.

video
Panning across the globular star cluster NGC 6362

This brilliant ball of stars lies in the southern constellation of Ara (The Altar). It can be easily seen in a small telescope. It was first spotted in 1826 by the Scottish astronomer James Dunlop using a 22-centimetre telescope in Australia.

More information:

The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

    Photos of the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

    Other photos taken with the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=15

    Photos of La Silla: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO / Richard Hook / IAU and Sky & Telescope / Digitized Sky Survey 2 / Acknowledgement: Davide De Martin / ESA/ Hubble & NASA / Videos: ESO/NASA/ESA/Hubble, Nick Risinger (skysurvey.org), Digitized Sky Survey 2 / Music: delmo "acoustic".

Best regards, Orbiter.ch

The launch of the cargo spacecraft Progress M-17M











ROSCOSMOS - Russian Vehicles patch.

31/10/2012

 Soyuz-U & Progress M-17M launch

October 31 at 11:41.18 MSK (MSK - Moscow Time) from the launch complex of the platform 1 was launched Baikonur Launch Vehicle (ILV) Soyuz-U to transport cargo ship (THC) Progress M-17M.

video
Russian Cargo Craft Launches

According to the RCN in flight cyclogram 11:50.07 MSK spacecraft separated from the third stage of the launch vehicle and placed into the desired orbit.

Docking THC Progress M-17M from the International Space Station (service module Zvezda of the Russian segment of the ISS) is scheduled today at 17:40 MSK (3:41 a.m. EDT Wednesday).

Progress-M space cargo

Cargo ship should be delivered to the ISS more than 2.5 tonnes of cargo - scientific equipment and spare parts for the station, the fuel to maintain its orbit, food, water and air for the astronauts.

Original text in  Russian: http://www.federalspace.ru/main.php?id=2&nid=19653

For more information about International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images, Video, Text, Credits: ROSCOSMOS / NASA / NASA TV / Translation: Orbiter.ch.

Cheers, Orbiter.ch