vendredi 7 octobre 2011

NASA Leads Study of Unprecedented Arctic Ozone Loss












NASA - CNES - DLR Calipso logo labeled / NASA - EOS Aura Mission patch.

Oct. 7, 2011

A NASA-led study has documented an unprecedented depletion of Earth's protective ozone layer above the Arctic last winter and spring caused by an unusually prolonged period of extremely low temperatures in the stratosphere.

The study, published online Sunday, Oct. 2, in the journal Nature, finds the amount of ozone destroyed in the Arctic in 2011 was comparable to that seen in some years in the Antarctic, where an ozone "hole" has formed each spring since the mid-1980s. The stratospheric ozone layer, extending from about 10 to 20 miles (15 to 35 kilometers) above the surface, protects life on Earth from the sun's harmful ultraviolet rays.


Image above: Left: Ozone in Earth's stratosphere at an altitude of approximately 12 miles (20 kilometers) in mid-March 2011, near the peak of the 2011 Arctic ozone loss. Right: chlorine monoxide – the primary agent of chemical ozone destruction in the cold polar lower stratosphere – for the same day and altitude. Image credit: NASA/JPL-Caltech.

The Antarctic ozone hole forms when extremely cold conditions, common in the winter Antarctic stratosphere, trigger reactions that convert atmospheric chlorine from human-produced chemicals into forms that destroy ozone. The same ozone-loss processes occur each winter in the Arctic. However, the generally warmer stratospheric conditions there limit the area affected and the time frame during which the chemical reactions occur, resulting in far less ozone loss in most years in the Arctic than in the Antarctic.

To investigate the 2011 Arctic ozone loss, scientists from 19 institutions in nine countries (United States, Germany, The Netherlands, Canada, Russia, Finland, Denmark, Japan and Spain) analyzed a comprehensive set of measurements. These included daily global observations of trace gases and clouds from NASA's Aura and CALIPSO spacecraft; ozone measured by instrumented balloons; meteorological data and atmospheric models. The scientists found that at some altitudes, the cold period in the Arctic lasted more than 30 days longer in 2011 than in any previously studied Arctic winter, leading to the unprecedented ozone loss. Further studies are needed to determine what factors caused the cold period to last so long.

video
Unprecedented Arctic Ozone Loss in 2011

"Day-to-day temperatures in the 2010-11 Arctic winter did not reach lower values than in previous cold Arctic winters," said lead author Gloria Manney of NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the New Mexico Institute of Mining and Technology in Socorro. "The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time. This implies that if winter Arctic stratospheric temperatures drop just slightly in the future, for example as a result of climate change, then severe Arctic ozone loss may occur more frequently."

The 2011 Arctic ozone loss occurred over an area considerably smaller than that of the Antarctic ozone holes. This is because the Arctic polar vortex, a persistent large-scale cyclone within which the ozone loss takes place, was about 40 percent smaller than a typical Antarctic vortex. While smaller and shorter-lived than its Antarctic counterpart, the Arctic polar vortex is more mobile, often moving over densely populated northern regions. Decreases in overhead ozone lead to increases in surface ultraviolet radiation, which are known to have adverse effects on humans and other life forms.

CALIPSO satellite

Although the total amount of Arctic ozone measured was much more than twice that typically seen in an Antarctic spring, the amount destroyed was comparable to that in some previous Antarctic ozone holes. This is because ozone levels at the beginning of Arctic winter are typically much greater than those at the beginning of Antarctic winter.

Manney said that without the 1989 Montreal Protocol, an international treaty limiting production of ozone-depleting substances, chlorine levels already would be so high that an Arctic ozone hole would form every spring. The long atmospheric lifetimes of ozone-depleting chemicals already in the atmosphere mean that Antarctic ozone holes, and the possibility of future severe Arctic ozone loss, will continue for decades.

EOS AURA Satellite

"Our ability to quantify polar ozone loss and associated processes will be reduced in the future when NASA's Aura and CALIPSO spacecraft, whose trace gas and cloud measurements were central to this study, reach the end of their operational lifetimes," Manney said. "It is imperative that this capability be maintained if we are to reliably predict future ozone loss in a changing climate."

Other institutions participating in the study included Alfred Wegener Institute for Polar and Marine Research, Potsdam, Germany; NASA Langley Research Center, Hampton, Va.; Royal Netherlands Meteorological Institute, De Bilt, The Netherlands; Delft University of Technology, 2600 GA Delft, The Netherlands; Science Systems and Applications, Inc., Greenbelt, Md., and Hampton, Va.; Science and Technology Corporation, Lanham, Md.; Environment Canada, Toronto, Ontario, Canada; Central Aerological Observatory, Russia; NOAA Earth System Research Laboratory, Boulder, Colo.; Arctic Research Center, Finnish Meteorological Institute, Finland; Danish Climate Center, Danish Meteorological Institute, Denmark; Eindhoven University of Technology, Eindhoven, The Netherlands; Arctic and Antarctic Research Institute, St. Petersburg, Russia; National Institute for Environmental Studies, Japan; National Institute for Aerospace Technology, Spain; and University of Toronto, Ontario, Canada.

For more information on NASA's Aura mission, visit: http://www.nasa.gov/aura . For more information on NASA's CALIPSO mission, visit: http://www.nasa.gov/calipso

JPL is managed for NASA by the California Institute of Technology in Pasadena.

Images, Video, Text, Credits: NASA / JPL-Caltech / Alan Buis / Steve Cole.

Greetings, Orbiter.ch

Mars Express observes clusters of recent craters in Ares Vallis












ESA - Mars Express Mission patch.

7 October 2011

(Click on the images for enlarge)

 Oraibi crater in Ares Vallis

Newly released images taken by ESA’s Mars Express show an unusual accumulation of young craters in the large outflow channel called Ares Vallis. Older craters have been reduced to ghostly outlines by the scouring effects of ancient water.

In the distant past, probably over 3.8 billion years ago, large volumes of water must have rushed through the Ares Vallis with considerable force. Mars Express imaged the preserved aftermath of this scene on 11 May 2011.

The prominent Oraibi crater lies in the channel and is about 32 km across. It is filled with sediments and its southern rim has been eroded by water. NASA’s Pathfinder mission landed in this region in 1997, 100 km to the north of the crater and off the right-hand side of this image.

Oraibi crater in Ares Vallis in context

The great outflow that partially eroded Oraibi also cut stepped riverbanks and excavated parallel channels in the riverbed that indicate the flow path. Streamlined islands have been left standing above the valley floor, again indicating the direction taken by the flow.

On the floor and on the plateau to the left of the image there are a number of ‘ghost craters’. These were once fully formed craters, but water or wind eroded their rims and filled them by depositing sediments. Their presence on the plateau suggests that even that higher ground may have been at least partially overrun by flooding. The solitary mounds that can be seen likely represent the remaining sections of the plateau’s original surface.

In addition to these heavily eroded, ancient features, however, there is evidence in the image for an impact on the martian surface in the much more recent past.

Features in Ares Vallis

On the far left side of the image, parts of an ejecta blanket can be seen, made of material excavated from the ground during the formation of an impact crater. In the upper left corner of the image, there is a landslide roughly 4 km wide, probably caused by the same impact, and surrounding the landslide, single streaks of ejecta can be traced out.

Ares Vallis in perspective

Furthermore, there are numerous small craters in the image, appearing both in clusters and in aligned groups. An abundance of such craters can result when an asteroid or other projectile breaks up into many pieces in the atmosphere before crashing to the ground.

Ares Vallis in perspective

Clusters of craters may also be created when a large impact ejects rock fragments with such force that they travel from a few kilometres to hundreds of kilometres before returning to the surface, creating new impacts called secondary craters.

Oraibi crater in perspective

The clusters of craters in this image are relatively young and likely formed within the past 20 million years: erosion would have erased them if they had occurred a long time ago.

Ares Vallis in perspective

 Ares Vallis in high resolution

 Ares Vallis in 3D

Related links:

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

For specialists:

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Greetings, Orbiter.ch

jeudi 6 octobre 2011

Astronomers Find Elusive Planets in Decade-Old Hubble Data












NASA - Hubble Space Telescope patch.

10.06.11

In a painstaking re-analysis of Hubble Space Telescope images from 1998, astronomers have found visual evidence for two extrasolar planets that went undetected back then.

Finding these hidden gems in the Hubble archive gives astronomers an invaluable time machine for comparing much earlier planet orbital motion data to more recent observations. It also demonstrates a novel approach for planet hunting in archival Hubble data.


Image description: (click on the image for enlarge)

Left: This is an image of the star HR 8799 taken by Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in 1998. A mask within the camera (coronagraph) blocks most of the light from the star. In addition, software has been used to digitally subtract more starlight. Nevertheless, scattered light from HR 8799 dominates the image, obscuring any details.

Center: Recent, sophisticated software processing of the NICMOS data removes most of the scattered starlight to reveal three planets orbiting HR 8799. The positions of these planets coincide with orbits of planets observed by ground-based telescopes in 2007 and 2008.

Right: This is an illustration of the HR 8799 exoplanet system based on the reanalysis of Hubble NICMOS data and ground-based observations. The positions of the star and the orbits of the four known planets are shown schematically. The size of the dots is not to scale with their true size. The three outermost planets, a, b, and c are detected in both the NICMOS and ground-based data. A fourth, inner planet, e was detected in ground-based observations. The orbits appear elongated because of a slight tilt of the plane of the orbits relative to our line of sight. The size of the HR 8799 planetary system is comparable to our solar system, as indicated by the orbit of Neptune, shown to scale. Credit: NASA; ESA; STScI, R. Soummer.

Four giant planets are known to orbit the young, massive star HR 8799, which is130 light-years away. In 2007 and 2008 the first three planets were discovered in near-infrared ground-based images taken with the W.M. Keck Observatory and the Gemini North telescope by Christian Marois of the National Research Council in Canada and his team. Marois and his colleagues then uncovered a fourth innermost planet in 2010. This is the only multiple exoplanetary system for which astronomers have obtained direct snapshots.

In 2009 David Lafreniere of the University of Montreal recovered hidden exoplanet data in Hubble images of HR 8799 taken in 1998 with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). He identified the position of the outermost planet known to orbit the star. This first demonstrated the power of a new data-processing technique for retrieving faint planets buried in the glow of the central star.

A new analysis of the same archival NICMOS data by Remi Soummer of the Space Telescope Science Institute in Baltimore has recovered all three of the outer planets. The fourth, innermost planet is 1.5 billion miles from the star and cannot be seen because it is on the edge of the NICMOS coronagraphic spot that blocks the light from the central star.

By finding the planets in multiple images spaced over years of time, the orbits of the planets can be tracked. Knowing the orbits is critical to understanding the behavior of multiple-planet systems because massive planets can perturb each other's orbits. "From the Hubble images we can determine the shape of their orbits, which brings insight into the system stability, planet masses and eccentricities, and also the inclination of the system," says Soummer.

These results are to be published in the Astrophysical Journal.

The three outer gas-giant planets have approximately 100-, 200-, and 400-year orbits. This means that astronomers need to wait a very long time to see how the planets move along their paths. The added time span from the Hubble data helps enormously. "The archive got us 10 years of science right now," he says. "Without this data we would have had to wait another decade. It's 10 years of science for free."

Nevertheless, the slowest-moving, outermost planet has barely changed position in 10 years. "But if we go to the next inner planet we see a little bit of an orbit, and the third inner planet we actually see a lot of motion," says Soummer.

The planets weren't found in 1998 when the Hubble observations were first taken because the methods used to detect them were not available at that time. When astronomers subtracted the light from the central star to look for the residual glow of planets, the residual light scatter was still overwhelming the faint planets.

Lafreniere developed a way to improve this type of analysis by using a library of reference stars to more precisely remove the "fingerprint" glow of the central star. Soummer's team took Lafreniere's method a step further and used 466 images of reference stars taken from a library containing over 10 years of NICMOS observations assembled by Glenn Schneider of the University of Arizona.

Hubble in orbit

Soummer's team further increased contrast and minimized residual starlight. They completely removed the diffraction spikes, which are artifacts common to telescope imaging systems. This allowed them to see two of the faint inner planets in the Hubble data. The planets recovered in the NICMOS data are about 1/100,000th the brightness of the parent star when viewed in near-infrared light.

Soummer next plans to analyze approximately 400 other stars in the NICMOS archive with the same technique, improving image quality by a factor of 10 over the imaging methods used when the data were obtained.

Soummer's work demonstrates the power of the Hubble Space Telescope data archive, which harbors images and spectral information from over twenty years of Hubble observations. Astronomers tap into this library to complement new observations with a wealth of invaluable data already gathered, yielding much more discovery potential than new observations alone.

From the NICMOS archive data Soummer's team will assemble a list of planetary candidates to be confirmed by ground-based telescopes. If new planets are discovered they will once again have several years' worth of orbital motion to measure.

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

NASA Hubble website: http://hubblesite.org/

ESA Hubble website: http://www.spacetelescope.org/

Images, Text, Credits: NASA / ESA / STScI / R. Soummer.

Greetings, Orbiter.ch

Spacecraft "Intelsat-18" into orbit












ROSCOSMOS logo.

06/10/2011

Zenit-2SB carrying  Intelsat-18 few second before the launch

October 6 at 01.00.02 GMT from 45th Baikonur site conducted a successful launch of space rocket "Zenit-2SB" with the upper stage, "DM-SLB," and U.S. telecommunications spacecraft "Intelsat-18."

Zenit-2SB - Intelsat-18 launch

Today at 07.34.29 GMT spacecraft "Intelsat-18" separated from booster "DM-SLB," and was referred to the management of the customer.

video
Zenit-2SB - Intelsat-18 launch

Spacecraft "Intelsat-18" - telecommunications satellite C and Ku-bands for the provision of data services and video services in North America, Australia, New Zealand, East Asia and Pacific region.

Intelsat-18 in orbit

Images, Text, Credit: Press Service of the Russian Space Agency (Roscosmos PAO) / Orbital / Translation: Orbiter.ch.

Cheers, Orbiter.ch

HotelsInSpace












HotelsInSpace - Tasha9503.com patch.


Oct. 6, 2011

HotelsInSpace

The story goes on

- In 1961, the first man went to space and back.

- In 1969 man went to the moon.

- In 1988 Trevor started looking for all the reasons why it is impossible to go the Asteroid Belt to mine smelt and manufacture living accommodations on location.

- In 1995 the last of the needed technology was becoming old, used and proven true.

- In 2000 all the technology was found and designed into a facility that can be built with six launches.

A reshaped Saturn V rocket with updated life support, Computer, Rocket engine etc. all repositioned within the hardware.

- In 2007, http://www.tasha9503.ca was put on the internet to show the new design for a Heavy Lift Vehicle.

- In 2009, it cost $20,000,000 to lift one satellite, Tasha9503 plans to lift six satellites per launch and charge $6,000,000 each. (2009 dollars)

- In 2010, http://www.youtube.com/watch?v=ivHAO96FIiw was used to show everyone what we will have when we use the new design for the rocket hardware and attach 6 together after reaching orbital velocity. Interior decorating not included in the video.

- In 2010, http://www.LivingInSpace.ca was produced to create the ability to sell 85% of the infrastructure Tasha9503 puts in LEO, offering time and profit shares to those who invest the start up expense.

We put together a business plan. http://tasha9503.com/Business%20Plan.pdf

We keep track of all contributors. http://tasha9503.com/tradesforownership.html

- In 2011, http://www.LivingInSpace.org was added to open up communications.

- In 2011, http://HotelsInSpace1.blogspot.com was added so we had a Blog.

Fifty years later, Tasha9503 wants to lift 213 people per launch and reuse the hardware that lifted them as infrastructure in Space.

Each link is different but all on the topic of HotelsInSpace by Tasha9503.

HotelsInSapce - Restaurant

Did you laugh at, or would you invest in:

Guglielmo Marconi? for dreaming of the radio. Alexander Bell? about the telephone? Christopher Columbus? Did he fall off the Earth? Henry Ford? Who needed a car? No roads anyway. Thomas Edison? The oil-less light bulb? Ben Franklin? with his kite strings. Jay Edger Hover? and his dream of an electrical dam. the Wright Brothers? It will never fly Orville. Man was never meant to fly.

May I go on? Most people knew better and laughed at these dreamers, knowing it will never happen.

Edgar Alan Poe? Aristotle? Michel Angelo? Einstein? Samuel Morris? Leonardo da Vinci? We laugh at the people who see what we cannot and attempt to lift us to new heights.

 HotelsInSpace in orbit

We nailed one man to a cross for trying to teach us to love each other and stop cheating, lying and hurting each other. Do you laugh at the design Tasha9503 wants to use as HotelsInSpace or the man who designed it?

Trevor just used the technology available to him to reshape the Saturn V rocket, update the life support systems, lower everyone’s launch costs and still produce profits, putting the general public in space by the hundreds.

HotelsInSpace - Ramp

Everyone told Trevor why it will take 50 years or it will never happen

- 27,000 degree hot plasma, going right through you

- Bone and muscle degradation, body turns week

- lubrication, allowing to spin different sections

- food supply, everyone must eat

- profitability, people will not invest without the promise of a profitable return, and you can’t afford it.

- launch expense

- atmospheric cleansing

The list goes on

 HotelsInSpace - First Floor

- clients, who will afford to rent HotelsInSpace at $1,000,000/week?

- Health, doctors, medication

- Human excrement

- Time, too much time to travel from one planet to another; imagine time to travel to another star.

And one by one business, scientists and farmers developed all the technology to fulfill all the restrictions.

Stories about all the needed tech was displayed on the Discovery Chanel.

HotelsInSpace - Second Floor Room's

David Suzuki, Jay Ingram and a few others with their many co-hosts brought the needed information together that solve all the stoppers, allowing humans to fly off this nest called Earth, without the need to land on another planet.

- wiring, increases the mini magnetosphere to magnetically protect the inhabitants from solar plasma.

- spin parts of the infrastructure to produce 6 levels of artificial gravity.

- MAGlev technology allows the union of two or more things with zero friction

- lift the food requirements for each guest with the guest.

- grow food on board

- every six launches produces 1,278 Astronauts and another piece of infrastructure that can be rented out as HotelsInSpace to produce profits

- the price for every launch is shared between 200 people and six satellite payloads

- updated air scrubbers from submarines, scuba and the ISS with six independent gardens

- a few large corporations buying large sections

- a few millionaires buying in to make profits

- many people buying small time and profit shares at $25/week

- staff of 24 to care for guests

- gardening section with compost and potting soil preparation.

- we have a 10 generation life expectancy increasing plan

HotelsInSpace- Room

Want me to go on?

Being unfunded momentarily, we have a 50 year plan and a 7 year plan.

The 50 year plan is you tell two people and they tell two people.

The 7 year plan is you tell 10,000 people and they tell 10,000 people.

If you want us to build, now, tell 100,000 people, twice. (Thats Called Advertising Or Spam)

Should one million people tell the governments to adopt this design?

Should one million people invest $10,000 and each own a small percent at 12% return?

HotelsInSpace - Room

Should one organization own the whole thing?

Trevor found a way to get off this planet, mine the Asteroid belt, smelt and manufacture reproductions on location. But to afford the start up costs he has to sell 85% of the infrastructure Tasha9503 puts in space. Then use the infrastructure as 72 unit HotelsInSpace. 1995 technology will mass produce these HotelsInSpace and lift 213 people per launch but not cover the walls with iPad technology. We need 1,000,000 people (Trekies) to subscribe for seven years or we need 1000 millionaires to invest $7,488,000 each.

52 weeks x 72 units x $2,000,000 = $7,488,000,000 start up costs.

One million people investing $25/week for seven years

52 weeks x $25 x 7 years x 1,000,000 people = $9,100,000,000 start up costs

$1,000,000 to rent one unit for one week.

$25/week to own time and profit shares with a subscription.

A site builder is needed who can extract all the information from each of these sites, then design and build a site that sells the concept.

To make the infrastructure affordable and profitable it was designed multi functional. As launch vehicles, they  can lift multiple satellites and a 213 passenger landing craft. As HotelsInSpace, each will sleep 216 people, lifting the food and water they need with each launch.

Trevor HM Cooper - Tasha9503

For Away Missions, each HotelsInSpace can grow enough food to feed 36 people indefinitely, so a 12 person crew can pass the Moon on a 99 year Away Mission.

For part of the sales pitch Tasha9503 is offering time and profit shares to those who invest, with every launch lifting one randomly chosen investor.  The day we begin collecting rent we are no longer for sale and your percent is registered.

trevor@tasha9503.com

Images, Video, Text, Credit: Trevor HM Cooper - Tasha9503 / HotelsInSpace / Layout, publication: Orbiter.ch.

Best regards, Orbiter.ch

ESA finds that Venus has an ozone layer too












ESA - Venus Express Mission patch.

6 October 2011

ESA’s Venus Express spacecraft has discovered an ozone layer high in the atmosphere of Venus. Comparing its properties with those of the equivalent layers on Earth and Mars will help astronomers refine their searches for life on other planets.

Venus Express made the discovery while watching stars seen right at the edge of the planet set through its atmosphere. Its SPICAV instrument analysed the starlight, looking for the characteristic fingerprints of gases in the atmosphere as they absorbed light at specific wavelengths.

video
Stellar occultation at Venus

The ozone was detectable because it absorbed some of the ultraviolet from the starlight.

Ozone is a molecule containing three oxygen atoms. According to computer models, the ozone on Venus is formed when sunlight breaks up carbon dioxide molecules, releasing oxygen atoms.

These atoms are then swept around to the nightside of the planet by winds in the atmosphere: they can then combine to form two-atom oxygen molecules, but also sometimes three-atom ozone molecules.

"This detection gives us an important constraint on understanding the chemistry of Venus' atmosphere," says Franck Montmessin, who led the research.

It may also offer a useful comparison for searching for life on other worlds.

Venus Express

Ozone has only previously been detected in the atmospheres of Earth and Mars. On Earth, it is of fundamental importance to life because it absorbs much of the Sun's harmful ultraviolet rays. Not only that, it is thought to have been generated by life itself in the first place.

The build-up of oxygen, and consequently ozone, in Earth's atmosphere began 2.4 billion years ago. Although the exact reasons for it are not entirely understood, microbes excreting oxygen as a waste gas must have played an important role.

Along with plant life, they continue to do so, constantly replenishing Earth's oxygen and ozone.

As a result, some astrobiologists have suggested that the simultaneous presence of carbon dioxide, oxygen and ozone in an atmosphere could be used to tell whether there could be life on the planet.

This would allow future telescopes to target planets around other stars and assess their habitability. However, as these new results highlight, the amount of ozone is crucial.

The small amount of ozone in Mars' atmosphere has not been generated by life. There, it is the result of sunlight breaking up carbon dioxide molecules.

video
Animation of planet Venus

Venus too, now supports this view of a modest ozone build-up by non-biological means. Its ozone layer sits at an altitude of 100 km, about four times higher in the atmosphere than Earth's and is a hundred to a thousand times less dense.

Theoretical work by astrobiologists suggests that a planet's ozone concentration must be 20% of Earth's value before life should be considered as a cause.

These new results support that conclusion because Venus clearly remains below this threshold.

"We can use these new observations to test and refine the scenarios for the detection of life on other worlds," says Dr Montmessin.

Yet, even if there is no life on Venus, the detection of ozone there brings Venus a step closer to Earth and Mars. All three planets have an ozone layer.

"This ozone detection tells us a lot about the circulation and the chemistry of Venus' atmosphere," says Håkan Svedhem, ESA Project Scientist for the Venus Express mission.

"Beyond that, it is yet more evidence of the fundamental similarity between the rocky planets, and shows the importance of studying Venus to understand them all."

Related links:

This story in depth: http://sci.esa.int/jump.cfm?oid=49412

ESApod: Venus Express: http://www.esa.int/SPECIALS/Venus_Express/SEMHXANFGLE_0.html

Looking at Venus: http://www.esa.int/SPECIALS/Venus_Express/index.html

Image, Text, Credits: ESA / C. Carreau / Animations by AOES Medialab.

Greetings, Orbiter.ch

mercredi 5 octobre 2011

Did Earth's oceans come from comets?












ESA - Herschel Mission patch.

5 October 2011

ESA's Herschel infrared space observatory has found water in a comet with almost exactly the same composition as Earth's oceans. The discovery revives the idea that our planet's seas could once have been giant icebergs floating through space.

The origin of Earth's water is hotly debated. Our planet formed at such high temperatures that any original water must have evaporated. Yet today, two-thirds of the surface is covered in water and this must have been delivered from space after Earth cooled down.

Comet Hartley 2 observed by ESA’s Herschel

Comets seem a natural explanation: they are giant icebergs travelling through space with orbits that take them across the paths of the planets, making collisions possible. The impact of comet Shoemaker-Levy 9 on Jupiter in 1994 was one such event. But in the early Solar System, when there were larger numbers of comets around, collisions would have been much more common.

However, until now, astronomers' observations have failed to back up the idea that comets provided Earth's water. The key measurement they make is the level of deuterium – a heavier form of hydrogen – found in water.
All the deuterium and hydrogen in the Universe was made just after the Big Bang, about 13.7 billion years ago, fixing the overall ratio between the two kinds of atoms. However, the ratio seen in water can vary from location to location. The chemical reactions involved in making ice in space lead to a higher or lower chance of a deuterium atom replacing one of the two hydrogen atoms in a water molecule, depending on the particular environmental conditions.

Comet Hartley 2’s orbit in context

Thus, by comparing the deuterium to hydrogen ratio found in the water in Earth's oceans with that in extraterrestrial objects, astronomers can aim to identify the origin of our water.

All comets previously studied have shown deuterium levels around twice that of Earth's oceans. If comets of this kind had collided with Earth, they could not have contributed more than a few percent of Earth's water. In fact, astronomers had begun to think that meteorites had to be responsible, even though their water content is much lower.

Now, however, Herschel has studied comet Hartley 2 using HIFI, the most sensitive instrument so far for detecting water in space, and has shown that at least this one comet does have ocean-like water.

"Comet Hartley's deuterium-to-hydrogen ratio is almost exactly the same as the water in Earth's oceans," says Paul Hartogh, Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany, who led the international team of astronomers in this work.

The Heterodyne Instrument for the Far Infrared (HIFI)

The key to why comet Hartley 2 is different may be because of where it was born: far beyond Pluto, in a frigid region of the Solar System known as the Kuiper Belt.

The other comets previously studied by astronomers are all thought to have formed near to Jupiter and Saturn before being thrown out by the gravity of those giant planets, only to return much later from great distances.

Thus the new observations suggest that perhaps Earth's oceans came from comets after all – but only a specific family of them, born in the outer Solar System. Out there in the deep cold, the deuterium to hydrogen ratio imprinted into water ice might have been quite different from that which arose in the warmer inner Solar System.

Herschel is now looking at other comets to see whether this picture can be backed up.

"Thanks to this detection made possible by Herschel, an old, very interesting discussion will be revived and invigorated," says Göran Pilbratt, ESA Herschel Project Scientist.

"It will be exciting to see where this discovery will take us."

Related links:

Herschel: ESA's giant infrared observatory: http://www.esa.int/SPECIALS/Herschel/index.html

Herschel overview: http://www.esa.int/SPECIALS/Herschel/index.html

Online Showcase of Herschel Images OSHI: http://oshi.esa.int/

This story in depth: http://sci.esa.int/jump.cfm?oid=49008

Herschel in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16

Images, Text, Credits: ESA / C. Carreau / AOES Medialab / Herschel / HssO Consortium.

Greetings, Orbiter.ch

Trigger-Happy Star Formation











NASA - Chandra X-ray Observatory patch.

Oct. 5, 2011


This composite image, created using data from the Chandra X-ray Observatory and the Spitzer Space Telescope, shows the molecular cloud Cepheus B, located in our galaxy about 2,400 light years from the Earth. A molecular cloud is a region containing cool interstellar gas and dust left over from the formation of the galaxy and mostly contains molecular hydrogen. The Spitzer data, in red, green and blue shows the molecular cloud (in the bottom part of the image) plus young stars in and around Cepheus B, and the Chandra data in violet shows the young stars in the field.

The Chandra observations allowed the astronomers to pick out young stars within and near Cepheus B, identified by their strong X-ray emission. The Spitzer data showed whether the young stars have a so-called "protoplanetary" disk around them. Such disks only exist in very young systems where planets are still forming, so their presence is an indication of the age of a star system.

These data provide an excellent opportunity to test a model for how stars form. The new study suggests that star formation in Cepheus B is mainly triggered by radiation from one bright, massive star (HD 217086) outside the molecular cloud. According to the particular model of triggered star formation that was tested -- called the radiation- driven implosion (RDI) model -- radiation from this massive star drives a compression wave into the cloud triggering star formation in the interior, while evaporating the cloud's outer layers.

Different types of triggered star formation have been observed in other environments. For example, the formation of our solar system was thought to have been triggered by a supernova explosion, In the star-forming region W5, a "collect-and-collapse" mechanism is thought to apply, where shock fronts generated by massive stars sweep up material as they progress outwards. Eventually the accumulated gas becomes dense enough to collapse and form hundreds of stars.

The RDI mechanism is also thought to be responsible for the formation of dozens of stars in W5. The main cause of star formation that does not involve triggering is where a cloud of gas cools, gravity gets the upper hand, and the cloud falls in on itself.

For more information about the Chandra mission and this result, including images and other multimedia, visit: http://www.nasa.gov/chandra and http://chandra.si.edu

Image, Text, Credit: X-ray: NASA / CXC / PSU / K. Getman et al.; IRL NASA / JPL-Caltech / CfA / J. Wang et al.

Greetings, Orbiter.ch

Very southern science at Concordia











IPEV - PNRA Concordia Antartica Base patch.

5 October 2011

Antarctica is a place of extremes: isolated, cold and dark during the southern winter. In short, it is a perfect location for unique science. ESA is again asking European scientists to submit ideas for research projects at Concordia station.

The Concordia research station in Antarctica is run by the French Polar Institute and the Italian Antarctic Programme, while ESA adds its space expertise in medical monitoring, testing life-support technologies and psychological training of crews staying over the long winter under extreme conditions.

A stunning view from the Concordia research station

Fundamental research on human adaptation in harsh environments is a pillar of Concordia’s work: the location provides many of the stresses that will be faced by future long missions to the Moon or Mars.

To this end, ESA is coordinating regular Announcements of Opportunity for all research in medicine, physiology and psychology at Concordia. This is the fourth announcement since 2003.

Announcement of Opportunity

Duration of the experiments should be up to two years; longer projects must be resubmitted after this period. Multidisciplinary research is welcome.


Image above: The Concordia Station is a scientific base built in Antarctica by the French Polar Institute (IPEV) and the Italian Antarctic Programme (PNRA).

Interested scientists are asked to send Letters of Intent before 4 November; a proposal workshop will be held at ESTEC in the Netherlands on 21 November.

The final proposals are due on 9 January 2012.

Depending on their complexity, some proposals may be implemented for the 2013 winter season, implying shipping of equipment and crew training in autumn 2012. The other selected projects will begin in the following seasons.

Concordia station

The flat landscape around Concordia is 3200 m above sea level. Equal to equatorial altitude of almost 4000 m, the air pressure is only 645 hPa, leading to chronic hypobaric hypoxia.

Concordia's location

During the winter, Concordia is under almost total darkness. With an average temperature of –51°C and a record low of –85°C, the conditions are harsh during the winter, limiting access to the austral summer of November to February.

Studies conducted at Concordia include glaciology, atmospheric sciences, astronomy, Earth sciences, technology, human biology and medicine – all benefitting from the unique environment in the middle of the Antarctic continent.

The station houses a team of typically 12–14 during the winter, selected through strict medical and psychological screening.

ESA's doctor Alex Salam at Concordia

The team consists of technicians, scientists, a cook and at least one medical doctor. They are responsible for the scientific work and operating the station, and their stay may last up to 14 months.

The French coastal station Dumont d’Urville is 1100 km away, while the Italian Mario Zucchelli Station at Terra Nova Bay lies 1200 km distant.

Further information, contact person and other details are available in the linked Announcement of Opportunity (below).

Concordia: http://www.esa.int/SPECIALS/Concordia/index.html

Concordia Announcement of Opportunity: http://www.esa.int/SPECIALS/Concordia/SEMTI69U7TG_0.html

Announcement of Opportunity 2011 (pdf): http://esamultimedia.esa.int/docs/hsf_research/AO-11-Concordia_v2.doc

Images, Text, Credits: ESA / Alex Salam / Mark Drinkwater / IPEV.

Best regards, Orbiter.ch

Observation Completion by Advanced Microwave Scanning Radiometer-EOS (AMSR-E)








JAXA logo labeled.

October 5, 2011

The Japan Aerospace Exploration Agency (JAXA) has been operating the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) for over nine years (despite a design life of three years) as an onboard device installed in the American earth observation satellite Aqua, after its launch on May 4, 2002. Since the end of August, 2011, however, the continuous increase of relatively large antenna rotation friction was detected twice, thus JAXA has been monitoring the condition. At 3:58 p.m. on October 4, 2011 (Japan Standard Time,) the AMSR-E reached its limit(*1) to maintain the rotation speed necessary for regular observations (40 rotations per minute), and the radiometer automatically halted its observations and rotation.

JAXA will continue to analyze this problem, and take necessary measures to correct the situation. We will also launch the successor to the AMSR-E, the Global Change Observation Mission 1st- Water "SHIZUKU" (GCOM-W1.)

*1) When rotation friction occurs, it is necessary to produce a turning force (torque) to offset the friction in order to maintain the rotation speed. The limit in this context means the maximum value of the torque (4.5 Nm,) which the AMSR-E's motor can produce.

Aqua/AMSR-E

(Reference) AMSR-E achievements

The AMSR-E is a microwave scanning radiometer with the world's highest performance. It can observe global-scale water, including ocean ice, surface temperatures, vapors, precipitation and soil water, regardless of weather conditions or if it is day or night by measuring faint radio waves emitted from the Earth.

(1) Contributing to practical areas

The AMSR-E contributed to accuracy improvement of weather forecasts by meteorological agencies around the world such as the Japan Meteorological Agency as its data was used for numerical weather predictions and for determining the center of a typhoon.

It was also helpful for more efficient operations of fishing boats as the data was used for compiling ocean condition information for fishing by a fishing industry information service center and other organizations.
   
The radiometer also contributed to monitoring the Sea of Okhotsk by the Japan Coast Guard and editing a report on overseas food demands through studying global drought conditions by the Ministry of Agriculture, Forestry and Fisheries.

(2) Usefulness to water circulation and climate change fields

Through long-time continuous observations of the Arctic ice, the AMSR-E was very helpful for understanding the impact of global warming by clarifying the smallest Arctic ice area in the observation history in the summer of 2007, and the second largest decrease of the area in the observation history in the summer of 2011.

With data observed by other satellites, the radiometer's data greatly contributed to the global precipitation map. The data was also very useful for international climate change research.

For other AMSR-E achievements in the past, please also refer to the Space Activities Commission (SAC) report issued on Aug. 31, 2005.

SAC Report on Aug. 31, 2005 (Japanese language only):
http://www.jaxa.jp/press/2005/08/20050831_sac_amsr-e_j.html

Earth Observation Center: http://www.eorc.jaxa.jp/en/index.php

Mission website:

"Aqua" Earth Observation Satellite: http://www.jaxa.jp/projects/sat/aqua/index_e.html

Image, Text, Credit: Japan Aerospace Exploration Agency (JAXA).

Greetings, Orbiter.ch

mardi 4 octobre 2011

Arctic Sea Ice Continues Decline, Hits Second-Lowest Level












NASA - Operation IceBridge patch.

Oct. 4, 2011

Last month the extent of sea ice covering the Arctic Ocean declined to the second-lowest extent on record. Satellite data from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder showed that the summertime sea ice cover narrowly avoided a new record low.


Image above: NASA satellite data reveals how this year's minimum sea ice extent, reached on Sept. 9 as depicted here, declined to a level far smaller than the 30-year average (in yellow) and opened up Northwest Passage shipping lanes (in red). (Credit: NASA Goddard's Scientific Visualization Studio).

The Arctic ice cap grows each winter as the sun sets for several months and shrinks each summer as the sun rises higher in the northern sky. Each year the Arctic sea ice reaches its annual minimum extent in September. It hit a record low in 2007.

The near-record ice-melt followed higher-than-average summer temperatures, but without the unusual weather conditions that contributed to the extreme melt of 2007. "Atmospheric and oceanic conditions were not as conducive to ice loss this year, but the melt still neared 2007 levels," said NSIDC scientist Walt Meier. "This probably reflects loss of multiyear ice in the Beaufort and Chukchi seas as well as other factors that are making the ice more vulnerable."

Joey Comiso, senior scientist  at NASA's Goddard Space Flight Center in Greenbelt, Md., said the continued low minimum sea ice levels fits into the large-scale decline pattern that scientists have watched unfold over the past three decades.

"The sea ice is not only declining, the pace of the decline is becoming more drastic," Comiso said. "The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover."

video

This video shows Arctic sea ice from March 7, 2011, to Sept. 9, 2011, ending with a comparison of the 30-year average minimum extent (in yellow) and the Northwest Passage (shown in red). (Credit: NASA's Goddard Space Flight Center).

While the sea ice extent did not dip below the 2007 record, the sea ice area as measured by the microwave radiometer on NASA's Aqua satellite did drop slightly lower than 2007 levels for about 10 days in early September, Comiso said. Sea ice "area" differs from extent in that it equals the actual surface area covered by ice, while extent includes any area where ice covers at least 15 percent of the ocean.

Arctic sea ice extent on Sept. 9, the lowest point this year, was 4.33 million square kilometers (1.67 million square miles). Averaged over the month of September, ice extent was 4.61 million square kilometers (1.78 million square miles). This places 2011 as the second lowest ice extent both for the daily minimum extent and the monthly average. Ice extent was 2.43 million square kilometers (938,000 square miles) below the 1979 to 2000 average.

This summer's low ice extent continued the downward trend seen over the last 30 years, which scientists attribute largely to warming temperatures caused by climate change. Data show that Arctic sea ice has been declining both in extent and thickness. Since 1979, September Arctic sea ice extent has declined by 12 percent per decade.

"The oldest and thickest ice in the Arctic continues to decline, especially in the Beaufort Sea and the Canada Basin," NSIDC scientist Julienne Stroeve said. "This appears to be an important driver for the low sea ice conditions over the past few summers."

Climate models have suggested that the Arctic could lose almost all of its summer ice cover by 2100, but in recent years, ice extent has declined faster than the models predicted.

video

Video above: In a taped version of a live broadcast, NASA Cryosphere Program Manager Tom Wagner shares his insights on the 2011 minimum. (Credit: NASA's Goddard Space Flight Center).

NASA monitors and studies changing sea ice conditions in both the Arctic and Antarctic with a variety of spaceborne and airborne research capabilities. This month NASA resumes Operation IceBridge, a multi-year series of flights over sea ice and ice sheets at both poles. This fall's campaign will be based out of Punta Arenas, Chile, and make flights over Antarctica . NASA also continues work toward launching ICESat-2 in 2016, which will continue its predecessor's crucial laser altimetry observations of ice cover from space.

To see a NASA data visualization of the 2011 Arctic sea ice minimum as measured by the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) on Aqua, visit: http://www.nasa.gov/topics/earth/features/2011-ice-min.html

For more information about NASA and agency programs, visit: http://www.nasa.gov

Image (mentioned), Videos (mentioned) Text, Credit: NASA's Earth Science News Team / Patrick Lynch.

Greetings, Orbiter.ch

Galileo IOV satellites fuelled for launch












ESA - Galileo IOV logo.

4 October 2011

ESA’s first two Galileo navigation satellites are both now fuelled and checked for their launch by Soyuz from French Guiana on 20 October.

The two Galileo In-Orbit Validation satellites reached Europe’s Spaceport last month. Galileo’s second flight model, FM2, touched down on 7 September on an Antonov-124 and the Galileo Protoflight Model followed it seven days later on an Ilyushin 76.

Both satellites are now fuelled and ready to be mated this week onto the dispenser that will hold them in place during launch before deploying them into their final 23 222 km orbit.

Galileo IOV satellite

The combined payload stack – the dispenser and both satellites – will then be transported from the fuelling facility to the Upper Composite Integration Facility S3B for integration with their Fregat-MT upper stage and subsequent encapsulation.

Follow the Galileo In-Orbit Validation launch campaign from the new Soyuz-Galileo IOV minisite (see below link).

Dispenser check-out with upper stage

Soyuz from French Guiana

This month’s launch will be historic: the first Soyuz launch from a spaceport outside of Baikonur in Kazakhstan or Plesetsk in Russia.

As a medium-class vehicle, Soyuz will complement Ariane and Vega to extend the flexibility and competitiveness of Europe’s launcher family.

Encapsulated under fairing

Galileo

The first two Galileo IOV satellites, launched this month, will be followed next year by two more. This quartet of satellites, built by a consortium led by EADS Astrium Germany, will form the operational nucleus of the full Galileo satnav constellation.

Galileo IOV in orbit

They combine the best atomic clock ever flown for navigation – accurate to one second in three million years – with a powerful transmitter to broadcast precise navigation signals.

Soyuz-Galileo IOV launch minisite: http://www.esa.int/SPECIALS/Galileo_IOV/

Images, Text, Credits: ESA / P. Carril / S. Corvaja.

Cheers, Orbiter.ch