samedi 3 mars 2012

Asteroids - The trajectory of the disaster

Asteroid Alert.


A few days ago, astronomers discovered an asteroid have grown closer to the Earth from the Apollo family. Its diameter is about 50 meters. Scientists estimate that at its next turn, exactly one year later a heavenly body, which was named 2012 DA14, fly very close to us, at a distance of 27,000 kilometers. This is below the geostationary orbit, which is operated basic constellation. If the trajectory of the asteroid's orbit will change slightly, the researchers did not exclude a collision with our planet.

Apollo family asteroids

By sweeping the Earth asteroid the size of the Tunguska-like. These days, astronomers at Pulkovo Observatory have confirmed the approach of a body with a complex named 2012 DA14. Exactly one year later an asteroid with a diameter of 50 meters, fly at an altitude of 26,000 kilometers, below the orbit of satellites. Its trajectory can still change, and a collision with our planet is not excluded.

Pulkovo Observatory

"We have to keep track of each particular body and the consequences of a collision with the body. That is until we are ill prepared for this. Speaking of dangerous bodies of more than 50 meters in diameter, our knowledge is limited by only one percent of such bodies, "- says Boris Shustov, director of the Institute of Astronomy.

A huge part of the small objects in space standards, which tend to not notice the earth, even with the most advanced telescopes - meteor showers come from the Sun and not visible at optical wavelengths. They're called Taurids. Perhaps because of such a flow burst body, which fell in the Tunguska River in 1908, the year.

"It is possible that in this thread there is a body, may be even larger, and in this regard the Taurids have to learn. While no one was doing "- says Sergey Barabanov, Chief Zvenigorod Observatory of the RAS.

2012 DA14 asteroid trajectory

In 2002 this body was almost brought disaster. The so-called Vitim bolide fell seven hundred kilometers away from Irkutsk. Scientists suggest that it was not a meteorite, a fragment of a comet, which consisted of a mixture of ice, dust and frozen gases. After his fall, formed toxic substances harmful to humans.

"Vitim bolide is not as big, but it never happened when he was flying. Asteroids and comets whose orbital inclination is large, we simply do not know "- tells Elena Bakanas, Fellow of the Institute of Astronomy the fall of bodies from outer space do without casualties.

But this - yet. The largest - the size of 20 kilometers once fell into the territory of South Africa. Now - it's Vredefort crater with a diameter of 300 kilometers, with the towns and villages inside. But the comet collided with Earth in the Mexican Yucatan peninsula, turned the course of history.


"It happened 65 million years ago and is usually associated with this dramatic change in the Earth's biosphere, since 80 percent of all deaths at that time. The fall of bodies larger than 1 km lead to global consequences, no matter where it falls, will not find anyone "- says Boris Shustov, director of the Institute of Astronomy.

Humanity still has a chance to explore these unwelcome invaders. In 2036, the year the Earth will meet with the already created quite a stir Apophis. 400 meters in diameter, more than an aircraft carrier.

"We must be ready for this, we should be able to investigate it, very quickly. We need to advise what action to take, what to do with it - or try to deny, or destroy or evacuate and wait for the attack, prepare to minimize the consequences "- says Sergey Barabanov, head of the Zvenigorod Observatory of the RAS.

Zvenigorod Observatory

Federal Space Agency is ready to take control of space killer. In the interior design department developed a plan to send Apophis first beacon, and then the spacecraft, which could reject an asteroid on a trajectory.

"It will be necessary, above all, bring back radio beacon, which would have allowed us to determine its position accurately. And second, of course, solve the second problem - the study of Apophis as a celestial body, it is also very interesting "- says Maxim Martynov, Deputy General Designer of NPO. Lavochkin.

In order to successfully predict the asteroid and comet threat to our country is preparing a network of telescopes for continuous monitoring of the entire celestial sphere. It will be Russia's contribution to the security of the planet called Earth.

"No country alone can hardly cope with a major, major challenge. Because each country is limited to a certain area, it is natural global monitoring with only one country does not work. And in general quite expensive, difficult both theoretically and practically, this problem, plus the financial and capacious "- explains Gennady Raykunov, CEO TsNIIMASH.

This year, contrary to many predictions, the collisions with large asteroids are expected. But space is unpredictable. In September, the Earth is waiting, as experts say the "perfect solar storm" - an unprecedented release of solar energy. Worsen the health of people, many devices can be damaged.

"With a powerful flash can make a wire transmission line. I'm not talking about the less-studied problems of the impact on the biosphere, humans. There are many not fully clear, but it can also affect the increase in the number of heart attacks, suicides, "- said Vladimir Obridko, head of the Laboratory of IZMIRAN heliophysics.

Yet a global catastrophe in the near future, scientists are not waiting. Apocalypse on the Mayan calendar, to which the whole world is so actively preparing, in December of this year, it seems, will not happen. This postponement of mankind owes to use.

Original text in Russian:

Images, Text, Credits: ROSCOSMOS PAO / TV Studio Space Agency / ESA - Medialab / / Translation:


vendredi 2 mars 2012

Dark Matter Core Defies Explanation in NASA Hubble Image

NASA - Hubble Space Telescope patch.

March 2, 2012

Astronomers using data from NASA's Hubble Telescope have observed what appears to be a clump of dark matter left behind from a wreck between massive clusters of galaxies. The result could challenge current theories about dark matter that predict galaxies should be anchored to the invisible substance even during the shock of a collision.

Abell 520 is a gigantic merger of galaxy clusters located 2.4 billion light-years away. Dark matter is not visible, although its presence and distribution is found indirectly through its effects. Dark matter can act like a magnifying glass, bending and distorting light from galaxies and clusters behind it. Astronomers can use this effect, called gravitational lensing, to infer the presence of dark matter in massive galaxy clusters.

This technique revealed the dark matter in Abell 520 had collected into a "dark core," containing far fewer galaxies than would be expected if the dark matter and galaxies were anchored together. Most of the galaxies apparently have sailed far away from the collision.
"This result is a puzzle," said astronomer James Jee of the University of California in Davis, lead author of paper about the results available online in The Astrophysical Journal. "Dark matter is not behaving as predicted, and it's not obviously clear what is going on. It is difficult to explain this Hubble observation with the current theories of galaxy formation and dark matter."

Initial detections of dark matter in the cluster, made in 2007, were so unusual that astronomers shrugged them off as unreal, because of poor data. New results from NASA's Hubble Space Telescope confirm that dark matter and galaxies separated in Abell 520.

One way to study the overall properties of dark matter is by analyzing collisions between galaxy clusters, the largest structures in the universe. When galaxy clusters crash, astronomers expect galaxies to tag along with the dark matter, like a dog on a leash. Clouds of hot, X-ray emitting intergalactic gas, however, plow into one another, slow down, and lag behind the impact.

That theory was supported by visible-light and X-ray observations of a colossal collision between two galaxy clusters called the Bullet Cluster. The galactic grouping has become an example of how dark matter should behave.

Merging Galaxy Cluster Abell 520

Studies of Abell 520 showed that dark matter's behavior may not be so simple. Using the original observations, astronomers found the system's core was rich in dark matter and hot gas, but contained no luminous galaxies, which normally would be seen in the same location as the dark matter. NASA's Chandra X-ray Observatory was used to detect the hot gas. Astronomers used the Canada-France-Hawaii Telescope and Subaru Telescope atop Mauna Kea to infer the location of dark matter by measuring the gravitationally lensed light from more distant background galaxies.

The astronomers then turned to the Hubble's Wide Field Planetary Camera 2, which can detect subtle distortions in the images of background galaxies and use this information to map dark matter. To astronomers' surprise, the Hubble observations helped confirm the 2007 findings.

"We know of maybe six examples of high-speed galaxy cluster collisions where the dark matter has been mapped," Jee said. "But the Bullet Cluster and Abell 520 are the two that show the clearest evidence of recent mergers, and they are inconsistent with each other. No single theory explains the different behavior of dark matter in those two collisions. We need more examples."

The team proposed numerous explanations for the findings, but each is unsettling for astronomers. In one scenario, which would have staggering implications, some dark matter may be what astronomers call "sticky." Like two snowballs smashing together, normal matter slams together during a collision and slows down. However, dark matter blobs are thought to pass through each other during an encounter without slowing down. This scenario proposes that some dark matter interacts with itself and stays behind during an encounter.

Another possible explanation for the discrepancy is that Abell 520 has resulted from a more complicated interaction than the Bullet Cluster encounter. Abell 520 may have formed from a collision between three galaxy clusters, instead of just two colliding systems in the case of the Bullet Cluster.

Hubble Space Telescope

A third possibility is that the core contained many galaxies, but they were too dim to be seen, even by Hubble. Those galaxies would have to have formed dramatically fewer stars than other normal galaxies. Armed with the Hubble data, the group will try to create a computer simulation to reconstruct the collision and see if it yields some answers to dark matter's weird behavior.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For more information about Hubble visit:

ESA Hubble website:

For images and more information about Abell 520's dark core, visit:

For more information about dark matter, visit:

Images, Text, Credits: NASA, ESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University).


jeudi 1 mars 2012

Spitzer Telescope Finds Hidden Jet

NASA - SPITZER Space Telescope logo.

March 1, 2012

NASA's Spitzer Space Telescope took this image of a baby star sprouting two identical jets (green lines emanating from fuzzy star). The jet on the right had been seen before in visible-light views, but the jet at left -- the identical twin to the first jet -- could only be seen in detail with Spitzer's infrared detectors. The left jet was hidden behind a dark cloud, which Spitzer can see through.

The twin jets, in a system called Herbig-Haro 34, are made of identical knots of gas and dust, ejected one after another from the area around the star. By studying the spacing of these knots, and knowing the speed of the jets from previous studies, astronomers were able to determine that the jet to the right of the star punches its material out 4.5 years later than the counter-jet.

The new data also reveal that the area from which the jets originate is contained within a sphere around the star, with a radius of 3 astronomical units. An astronomical unit is the distance between Earth and the sun. Previous studies estimated that the maximum size of this jet-making zone was 10 times larger.

The wispy material is gas and dust. Arc-shaped bow shocks can be seen at the ends of the twin jets. The shocks consist of compressed material in front of the jets.

The Herbig-Haro 34 jets are located at approximately 1,400 light-years away in the Orion constellation.

Fore more information about Spitzer Space Telescope, visit:

Image, Text, Credit: NASA / JPL-Caltech.


Happy birthday, Envisat

ESA - ENVISAT Mission logo's.

1 March 2012

Happy birthday, Envisat!

In the early hours of 1 March 2002, the largest Earth observation satellite ever built soared into orbit from ESA’s launch base in Kourou, French Guiana. For a decade, Envisat has been keeping watch over our planet.

The eight-tonne satellite has doubled its planned five-year lifetime, circling Earth more than 50 000 times.

With ten sophisticated optical and radar sensors, the satellite is continuously observing and monitoring Earth’s land, atmosphere, oceans and ice caps. An estimated 2000 scientific publications have been based on this information. 

Envisat’s largest instrument is the Advanced Synthetic Aperture Radar, which can be used day or night because it sees through clouds and darkness. This is particularly useful over polar regions, which are prone to long periods of bad weather and extended darkness.

Arctic ice

Last summer, the radar monitored record-low sea ice cover in the Arctic.

The Medium Resolution Imaging Spectrometer – or MERIS – captures images of ocean colour and land cover.

MERIS images are used to produce high-resolution global land-cover maps under the GlobCover project. These maps are useful for modelling the extent and effects of climate change, conserving biodiversity and managing natural resources.

Nitrogen dioxide over Europe

Envisat’s MIPAS, Sciamachy and GOMOS suite of sensors is able to see the holes in the thinning ozone layer and the plumes of pollutants hanging over major industrial cities or burning forests.

They can simultaneously observe the atmosphere in ways the human eye cannot, producing detailed horizontal and vertical cross-sections of a series of chemical components.

Working like a thermometer in the sky, Envisat’s Advanced Along-Track Scanning Radiometer measures thermal-infrared radiation to take the temperature of Earth’s land and sea surfaces. The ATSR World Fire Atlas is one useful product.

Global hot spots

Other instruments include the Radar Altimeter, which measures surface topography to an accuracy of a few centimetres, revealing the changes in sea-surface height over time.

Envisat provides crucial Earth observation data not only to scientists, but also to many operational services such as sea ice mapping or oil spill monitoring.

High engineering and scientific skills keep the mission going – Envisat owes its decade of success to over ten years of teamwork.

With an increased demand from scientific users for Envisat products, the mission gradually increased the flow of data within the first five years. Ground facilities have improved over the years to speed the delivery of data and their quality.

Envisat soars into orbit

In 2004, the mission’s first scientific results were presented at the Envisat Symposium in Salzburg, Austria. With about 1000 participants, it marked the establishment of Envisat as one of the major tools available to Earth scientists.

Three years later, another symposium dedicated to Envisat included the first global measurements of greenhouse gases, demonstrating the fast-growing concentration of carbon dioxide and the seasonal variation of methane.

MERIS: plankton blooms

In 2010, the satellite’s orbit was changed to allow Envisat to continue operating for at least another three years.

This is ensuring the continuity of crucial Earth-observation data until the next generation of satellites – the Sentinels – are fully operational in 2013.

The Sentinel missions are being developed as part of Europe’s Global Monitoring for Environment and Security (GMES) programme.

For more Envisat achievements, visit Envisat’s tenth-birthday minisite:

Related links:

ATSR World Fire Atlas:


Envisat operations:

Images, Video, Text, Credits: ESA / CNES / Arianespace / S. Corvaja / DMI / NIC / University of Heidelberg.


mercredi 29 février 2012

Fledgling stars flicker in the heart of Orion

ESA Herschel Mission patch / NASA - SPITZER Space Telescope patch.

29 February 2012

Astronomers using ESA’s Herschel and NASA’s Spitzer space telescopes have detected surprisingly rapid changes in the brightness of embryonic stars within the well-known Orion Nebula.

Images from Herschel’s far-infrared instrument and two of Spitzer’s instruments working at shorter wavelengths give us a more detailed picture of stars growing in the heart of one of the most famous objects in the night sky.

The Orion Nebula is 1350 light years from Earth, and appears prominently in the winter skies for European observers.

Sometimes referred to as the Sword of Orion, the nebula lies below the three stars that form the belt of Orion the Hunter, one of the most easily recognised constellations.

It is one of the few nebulas visible to the naked eye and is a popular target for amateur astronomers.

Baby stars in Orion Nebula

The nebula contains the nearest site of massive star formation, with intense ultraviolet light from hot young stars causing gas and dust in the region to glow.

Inside that dust – hidden at visible wavelengths – is a host of even younger stars, still growing in their earliest phase of evolution.

This new combined far- and mid-infrared image cuts through the obscuring dust and reveals these embryonic stars.

A star forms when a dense cloud of gas and dust coalesces and then collapses under its own gravity, creating a central warm protostar surrounded by a swirling disc and a larger envelope.

Much of this material will spiral in and collect on to the star over hundreds of thousands of years, before nuclear fusion is triggered at the core and it becomes a fully-fledged star.

Some of the remnant gas and dust in the disc may go on to form a planetary system – as happened with our Solar System.

 ESA's Hershel

A team of astronomers led by Nicolas Billot of the Institut de Radioastronomie Millimétrique, in Granada, Spain used Herschel to image the Orion Nebula region once a week for six weeks in the late winter and spring last year.

Herchel’s PACS Photodetector Array Camera and Spectrometer detected cold dust particles in discs around the youngest protostars at far-infrared wavelengths.

This was combined with archival Spitzer images taken at shorter, mid-infrared wavelengths, which show older, hotter objects.

Astronomers were surprised to see the brightness of the young objects varying by more than 20% over just these few weeks, since the accretion process should take years or even centuries. They now have to explain why this is happening.

One possibility is that lumpy filaments of gas are funnelling from the outer disc towards central regions near the star, temporarily warming the inner disc and leading it to brighten.

Another scenario is that cold material is piling up at the inner edge and casting shadows on the outer disc, causing it to darken temporarily.


In either case, it is clear that the gestation of baby stars is anything but a smooth, uniform process.

“Yet again, Herschel observations surprise us and provide more interesting insights in to what happens during the very earliest phases of stars and planet formation,” comments Göran Pilbratt, ESA’s Herschel Project Scientist.

It is only through the unprecedented far-infrared sensitivity and resolution of the Herschel space observatory, combined with the shorter-wavelength data from Spitzer, that astronomers are able to witness and fully discover the physical processes of star birth. 

Related links:

Herschel: ESA's giant infrared observatory:

More on Herschel First Results:

Herschel overview:

Notes to editors:

Online Showcase of Herschel Images OSHI:

Herschel in depth:

Herschel first science results in depth:

Herschel Science Centre:

Images, Text, Credits: ESA / Markus Bauer / Institut de Radioastronomie Millimétrique / Nicolas Billot / PACS / NASA / JPL-Caltech / IRAM.


mardi 28 février 2012

Beside a Giant

NASA / ESA - Cassini-Huygens Mission patch.

Feb. 28, 2012

Saturn's largest moon, Titan, looks small here, pictured to the right of the gas giant in this Cassini spacecraft view.

Titan (3,200 miles, or 5,150 kilometers across) is in the upper right. Saturn's rings appear across the top of the image, and they cast a series of shadows onto the planet across the middle of the image.

The moon Prometheus (53 miles, or 86 kilometers across) appears as a tiny white speck above the rings in the far upper right of the image. The shadow cast by Prometheus can be seen as a small black speck on the planet on the far left of the image, between the shadows cast by the main rings and the thin F ring. The shadow of the moon Pandora also can be seen on the planet south of the shadows of all the rings, below the center of the image towards the right side of the planet. Pandora is not shown here.

This view looks toward the southern, unilluminated side of the rings from about 1 degree below the ringplane.

The image was taken with the Cassini spacecraft wide-angle camera on Jan. 5, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers. The view was acquired at a distance of approximately 426,000 miles (685,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 20 degrees. Image scale is 23 miles (37 kilometers) per pixel on Saturn. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about Cassini Mission, visit:

NASA - Cassini:

ESA - Cassini-Huygens:

Image, Text, Credit: NASA / JPL-Caltech / Space Science Institute.


André’s PromISSe mission extended on Space Station

ESA - PromISSe Mission patch.

28 February 2012

ESA astronaut André Kuipers will stay on the International Space Station for more than a month longer than originally planned. In addition to his normal routine he will spend some of the extra time conducting scientific experiments.

The Station partners have agreed that this expedition will be prolonged following a delay in the launch of the next Soyuz crew ferry.

Soyuz docked to Station

Routine testing revealed problems in the original Soyuz spacecraft, requiring that it be replaced. The new date for André and his crewmates to return to Earth is 1 July – he will now stay on the Space Station for over six months.

The extra time André has in space does not mean he will have time for extra work because the science and maintenance activities continue regardless of which astronaut is available to do the job.

Owing to the delay, the Space Station will operate with only three crewmembers for a longer period than originally planned. 

Science experiments

Space food

André has already completed some of his experiments. He was the tenth astronaut to follow the special SOLO diet to understand why astronauts lose bone density in space.

For five days, André ate only a third of the salt found in a normal diet. The results may offer insights into how bones age on Earth and could be used to combat diseases such as osteoporosis.

André completed the DSC experiment in the European-built Microgravity Science Glovebox, looking at temperature changes in mixtures of different fluids.

The results of this experiment will contribute to improving computer models used in oil drilling.

André recently shared a picture from the Space Station wearing what looked like a bathing cap. Worn for the Neurospat experiment, it is actually a complex network of electrodes for measuring his brain waves.

André records his brain waves

A total of 64 electrodes were carefully and precisely placed on André’s head by colleague Don Pettit. The goal is to understand if the brain processes some tasks differently in space.

André has also finished the Roald2 biology experiment on human immune cells. Astronauts’ immune systems work less effectively in space and scientists are trying to find out why.

Immune cells taken from volunteers on Earth were chemically frozen on the Space Station at specific intervals. By looking closely at the cells once they return to Earth, scientists hope to gain insight into the workings of the human immune system.

There are many scientific experiments still to finish. Maintenance work waits for no one so André and his crewmates will be busy keeping the Space Station running smoothly.

In the highly unlikely possibility that André has time to spare, the scientists on Earth have a set of ‘back-pocket’ activities available that could be conducted at short notice should the opportunity arise.

Related links:

ESA PromISSe Mission:

ISS Expedition 30 (NASA):

ISS Expedition 31 (NASA):

Roscosmos (Russia):

Ruimteschip Aarde:

Images, Text, Credits: ESA / NASA.

Best regards,