Swirling Landscape of Stars

NASA - SPITZER Space Telescope logo.

Oct. 18, 2011

This swirling landscape of stars is known as the North America Nebula. In visible light, the region resembles North America, but in this image infrared view from NASA's Spitzer Space Telescope, the continent disappears.

Where did the continent go? The reason you don't see it in Spitzer's view has to do, in part, with the fact that infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars.

Clusters of young stars (about one million years old) can be found throughout the image. Some areas of this nebula are still very thick with dust and appear dark even in Spitzer's view.

The Spitzer image contains data from both its infrared array camera and multi-band imaging photometer. Light with a wavelength of 3.6 microns has been color-coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red. This image is from February 2011.

For more information about SPITZER Space Telescope, visit: http://www.spitzer.caltech.edu/

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

Greetings, Orbiter.ch

NASA, Japan Release Improved Topographic Map of Earth

NASA- EOS / TERRA Mission patch labeled.

Oct. 18, 2011

This flyover of the Hawaiian island of Oahu was made by draping Jan. 13, 2010, image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft over new ASTER Version 2 digital elevation data.

NASA and Japan released a significantly improved version of the most complete digital topographic map of Earth on Monday, produced with detailed measurements from NASA's Terra spacecraft.

The map, known as a global digital elevation model, was created from images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or ASTER, instrument aboard Terra. So-called stereo-pair images are produced by merging two slightly offset two-dimensional images to create the three-dimensional effect of depth. The first version of the map was released by NASA and Japan's Ministry of Economy, Trade and Industry (METI) in June 2009.

Image above: At 14,505 feet (4,421 meters) in elevation, California's Mt. Whitney, located in the Sierra Nevada Mountains on the west side of Owens Valley, is the highest point in the contiguous United States. Image credit: NASA / GSFC / METI / ERSDAC / JAROS, and U.S. / Japan ASTER Science Team.

"The ASTER global digital elevation model was already the most complete, consistent global topographic map in the world," said Woody Turner, ASTER program scientist at NASA Headquarters in Washington. "With these enhancements, its resolution is in many respects comparable to the U.S. data from NASA's Shuttle Radar Topography Mission, while covering more of the globe."

The improved version of the map adds 260,000 additional stereo-pair images to improve coverage. It features improved spatial resolution, increased horizontal and vertical accuracy, more realistic coverage over water bodies and the ability to identify lakes as small as 0.6 miles (1 kilometer) in diameter. The map is available online to users everywhere at no cost.

Image above: Arguably one of America's most magnificent national parks is the Grand Canyon in northern Arizona. Image credit: NASA / GSFC / METI / ERSDAC / JAROS, and U.S. / Japan ASTER Science Team.

"This updated version of the ASTER global digital elevation model provides civilian users with the highest-resolution global topography data available," said Mike Abrams, ASTER science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "These data can be used for a broad range of applications, from planning highways and protecting lands with cultural or environmental significance, to searching for natural resources."

The ASTER data cover 99 percent of Earth's landmass and span from 83 degrees north latitude to 83 degrees south. Each elevation measurement point in the data is 98 feet (30 meters) apart.

NASA and METI are jointly contributing the data for the ASTER topographic map to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes.

Image above: The Advanced Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft provided this spacebird's-eye view of the eastern part of Grand Canyon National Park in northern Arizona in this image, acquired July 14, 2011. Image credit: NASA / GSFC / METI / ERSDAC / JAROS, and U.S. / Japan ASTER Science Team.

ASTER is one of five instruments launched on Terra in 1999. ASTER acquires images from visible to thermal infrared wavelengths, with spatial resolutions ranging from about 50 to 300 feet (15 to 90 meters). A joint science team from the United States and Japan validates and calibrates the instrument and data products. The U.S. science team is located at JPL.

NASA, METI, Japan's Earth Remote Sensing Data Analysis Center (ERSDAC), and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data are distributed by NASA's Land Processes Distributed Active Archive Center at the U.S. Geological Survey's Earth Resources Observation and Science Center in Sioux Falls, S.D., and by ERSDAC in Tokyo.

Users of the new version of the ASTER data products are advised that while improved, the data still contain anomalies and artifacts that will affect its usefulness for certain applications.

Data users can download the ASTER global digital elevation model at: https://lpdaac.usgs.gov/ or http://www.ersdac.or.jp/GDEM/E/4.html .

For more information about ASTER, visit: http://asterweb.jpl.nasa.gov/ . For more information on NASA's Terra mission, visit: http://www.nasa.gov/terra .

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

Images (mentioned), Video (mentioned), Text, Credit: NASA / JPL / Alan Buis.

Best regards, Orbiter.ch

Stars Adorn Orion's Sword

NASA - SPITZER Space Telescope patch.

Oct. 18, 2011

 (Click on the image for enlarge)

This image from NASA's Spitzer Space Telescope shows what lies near the sword of the constellation Orion -- an active stellar nursery containing thousands of young stars and developing protostars. Many will turn out like our sun. Some are even more massive. These massive stars light up the Orion nebula, which is seen here as the bright region near the center of the image.

For more information about SPITZER Space Telescope, visit: http://www.spitzer.caltech.edu/

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

Cheers, Orbiter.ch

CryoSat rocking and rolling

ESA - CryoSat 2 logo.

17 October 2011

ESA’s ice satellite is rolling left and right in orbit to help it continue its precise measurements of the vast ice sheets that blanket Greenland and Antarctica.

Since its launch 18 months ago, CryoSat-2 has been collecting data to improve our understanding of the relationship between ice and climate.

Just this year, the first map of Arctic sea-ice thickness was unveiled, and the satellite will continue to monitor the changing ice for years to come.

CryoSat rocks and rolls

To ensure the precision of the measurements, an operation is under way to roll the satellite from side to side as it flies over the flat oceans.

This manoeuvre is to calibrate CryoSat’s radar altimeter for measuring ice thickness, especially over the margins of ice sheets.

The altimeter has two antennas mounted on a bench about a metre apart. When it is working in the ‘SARIn’ mode, both antennas are used in parallel: one emits a signal and both receive the signals that bounce back.

Normally, this bench is parallel to Earth’s surface. But at the edges of the ice sheets, the ice surface is not always flat and the slopes affect the return signals.

Measuring the freeboard of sea ice

Harsh conditions in space – with huge temperature differences between Sun and shade – can lead to the deterioration of CryoSat’s instruments, which can also lead to measurement errors.

In order to quantify these errors, ESA ground controllers are working to recalibrate the altimeter.

They are rolling the satellite to simulate the ice slopes and holding it in this position for several minutes. This must be done while CryoSat is over large, flat surfaces. For satellite altimeters, oceans are Earth’s largest flat surfaces.

It will also check whether errors are related to CryoSat’s varying thermal conditions – like when exposed to the Sun or in the shade.

“With the results from the different sets of rolls over different ocean surfaces and at different ambient conditions, we are aiming to characterise the instrument to a precision better than we thought we could make at the time of the launch,” said Tommaso Parrinello, CryoSat mission manager.

Arctic sea-ice thickness

During several manoeuvres on Monday and Tuesday, the satellite is rolling 0.4º to both sides while over the Indian and Pacific oceans, before returning to its original position.

“The preparations for the roll activities have been quite challenging,” explained Nic Mardle, spacecraft operations manager.

“Although we had experience of these activities from the commissioning phase, we had to iterate a few more times with the planning and mission control teams so that we could support exactly what was required.”

The complex calibration is a joint effort between ESA’s ESRIN centre for Earth observation in Italy and its ESOC operations centre in Germany.

CryoSat is dedicated to monitoring changes in the thickness of marine ice floating in the polar oceans and of the vast ice sheets that extend over Greenland and the Antarctic.

Satellites have already shown that the extent of sea ice in the Arctic is diminishing. In fact, this year’s minimum has set a new record low.

Related links:

CryoSat: http://www.esa.int/SPECIALS/Cryosat/index.html

Access CryoSat data: http://earth.esa.int/cryosat

ESRIN: http://www.esa.int/SPECIALS/ESRIN_SITE/index.html

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

Images, Animation, Text, Credits: ESA / M. Pinol (ESTEC) / AOES Medialab / CPOM / UCL.

Greetings, Orbiter.ch

Carina Nebula: 14,000+ Stars

NASA - Chandra X-ray Observatory patch.

Oct. 15, 2011

The Carina Nebula is a star-forming region in the Sagittarius-Carina arm of the Milky Way that is 7,500 light years from Earth and the Chandra X-Ray Observatory has detected more than 14,000 stars in the region.

Chandra's X-ray vision provides strong evidence that massive stars have self-destructed in this nearby star-forming region. Firstly, there is an observed deficit of bright X-ray sources in the area known as Trumpler 15, suggesting that some of the massive stars in this cluster were already destroyed in supernova explosions. Trumpler 15 is located in the northern part of the image and is one of ten star clusters in the Carina complex.

The detection of six possible neutron stars, the dense cores often left behind after stars explode in supernovas, provides additional evidence that supernova activity is increasing up in Carina. Previous observations had only detected one neutron star in Carina.

For more information about Chandra X-ray Observatory, visit: http://chandra.si.edu/

Image, Text, Credit: NASA / CXC / Penn State / L. Townsley et al.

Cheers, Orbiter.ch

Docking mission between Tiangong-1 & Shenzhou-8

CNSA - China National Space Agency logo.

Oct. 13, 2011

Launch of Shenzhou 8 and docking between Tiangong-1 & Shenzhou-8:

Launch date: 1 November 2011 (launch time: hours not reported).
Launch vehicle: Long March 2F
Payload: Shenzhou 8
Launch time: TBD
Launch site: Jiuquan, China

A Chinese Long March 2F rocket launch Shenzhou 8 Will we have n Conduct unmanned flight to the country's first docking spacecraft in orbit Between Two. Shenzhou 8 Will rendezvous and dock with the Tiangong 1 module Launched in September 2011.

Shenzhou 8 in thermal vacuum chamber test

The space module Tiangong-1 dock Shenzhou-8 to November 3. Tiangong-1 entered the designated orbit to await Shenzhou-8, a ship without a crew.

Once the two spacecraft have made their rendezvous in space, they dock with 340 km above the earth. According to the chief engineer of the project, the operation will take place two days after the launch of Shenzhou-8. Then Tiangong-1 will change to a higher orbit for the arrival of Shenzhou-9 and Shenzhou-10.

Docking between Tiangong-1 & Shenzhou-8 (Artist's view)

During the mission, experiments will be conducted with, among others, the University of Zurich in Switzerland:

- Project “Innate Immunity in microgravity”, SHENZHOU-8 Space Ship Mission, PI: Prof. Dr. Dr. Oliver Ullrich. German Aerospace Center DLR and China Manned Space Engineering Office (CMSEO).

Related Links:

University of Zurich (Switzerland): http://www.anatom.uzh.ch/research/Appliedanatomy-1/DivisionUllrich-1.html

China Space Administration: http://www.cnsa.gov.cn/n615709/cindex.html

Images, Text, Credits: CNSA / CASC / CMSEO / Orbiter.ch.

Greetings, Orbiter.ch

Hubble Survey Carries Out a Dark Matter Census

ESA - Hubble Space Telescope logo.

13 October 2011

 Hubble image of galaxy cluster MACS

The NASA/ESA Hubble Space Telescope has been used to make an image of galaxy cluster MACS J1206.2-0847. The apparently distorted shapes of distant galaxies in the background is caused by an invisible substance called dark matter, whose gravity bends and distorts their light rays. MACS 1206 has been observed as part of a new survey of galaxy clusters using Hubble.

Cluster MACS J1206.2-0847 (or MACS 1206 for short) is one of the first targets in a Hubble survey that will allow astronomers to construct the highly detailed dark matter maps of more galaxy clusters than ever before. These maps are being used to test previous but surprising results that suggest that dark matter is more densely packed inside clusters than some models predict. This might mean that galaxy cluster assembly began earlier than commonly thought.

Wide field view of MACS 1206 (ground-based image)

The Cluster Lensing And Supernova survey with Hubble (CLASH) probes, with unparalleled precision, the distribution of dark matter in 25 massive clusters of galaxies. So far, the CLASH team has observed six of the 25 clusters.

Dark matter makes up the bulk of the Universe’s mass, yet it can only be detected by measuring how its gravity tugs on visible matter and warps the fabric of space-time like a fairground mirror so that the light from distant objects is distorted.

Galaxy clusters like MACS 1206 are perfect laboratories for studying dark matter’s gravitational effects because they are the most massive structures in the Universe to be held together by gravity. Because of their immense gravitational pull, the clusters act like giant cosmic lenses, amplifying, distorting and bending any light that passes through them — an effect known as gravitational lensing.

Zoom on MACS 1206

Lensing effects can also produce multiple images of the same distant object, as is evident in this Hubble picture. In particular, the apparent numbers and shapes of the distant galaxies far beyond a galaxy cluster become distorted as the light passes through, yielding a visible measurement of how much mass there is in the intervening cluster, and how it is distributed. The substantial lensing distortions seen are proof that the dominant mass component of the clusters is dark matter. The distortions would be far weaker if the clusters’ gravity came only from visible matter.

MACS 1206 lies four billion light-years from Earth. Hubble’s keen vision helped CLASH astronomers to uncover 47 multiple images of 12 newly identified faraway galaxies. Finding so many multiple images in a cluster is a unique capability of Hubble, and the CLASH survey is optimised to find them. The new observations build on earlier work by Hubble and ground-based telescopes.

Among the observations which complement Hubble’s is a major project using the European Southern Observatory’s Very Large Telescope. Unlike Hubble, which is making images of the clusters, the VLT is carrying out spectroscopic observations, where instruments split up the galaxies’ light into their component colours letting the scientists draw inferences about many of the properties of the cluster galaxies, including their distance and chemical makeup.

Pan across MACS 1206

Taking advantage of two of Hubble’s powerful cameras, the Advanced Camera for Surveys and the Wide Field Camera 3, the CLASH survey covers a broad wavelength range, from ultraviolet to near-infrared.

Astronomers need the diverse colours to estimate the distances to the lensed galaxies and to study them in more detail. Hubble’s unique capabilities allow astronomers to estimate distances to galaxies that are four times fainter than those that ground-based telescopes can see.

The era when the first clusters formed is not precisely known, but is estimated to be at least nine billion years ago and possibly as far back as twelve billion years ago. If most of the clusters in the CLASH survey are found to have excessively high accumulations of dark matter in their central cores, then it may yield new clues about the early stages of the origin of structure in the Universe.

Future telescopes like the NASA/ESA/CSA James Webb Space Telescope (JWST), a space-based infrared observatory now being built, will be able to study the fainter lensed galaxies in clusters like MACS 1206 in greater detail. JWST will be powerful enough to observe the spectra of some of the magnified galaxies and study their early chemical composition.

Notes:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

    Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

    NASA release: http://hubblesite.org/news/2011/25

    CLASH survey: http://www.stsci.edu/~postman/CLASH/Home.html

Images, Text, Credits: NASA / ESA / M. Postman (STScI) and the CLASH Survey Team / Digitized Sky Survey 2 (Acknowledgement: Davide De Martin) / Videos: NASA / ESA / Digitzed Sky Survey 2 / M. Postman (STScI) and the CLASH Survey Team / Music: John Dyson (from the album Moonwind).

Greetings, Orbiter.ch