جزیره ی یخی بسوی جنوب می رود Ice Island Drifts Southward

As July 2011 progressed, the Petermann Ice Island-A (PII-A) continued drifting southward in the Labrador Sea. When the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image on July 27, 2011, PII-A was about 60 kilometers (40 miles) northeast of Newfoundland.

PII-A is a remnant of an ice island that calved off the Petermann Glacier along the northwestern coast of Greenland in August 2010. That ice island was about four times the size of Manhattan. In July 2011, PII-A was roughly the size of just one Manhattan, and the Canadian Ice Service reported that the ice island continued losing mass through breakup and melt. The ice island continued to pose a potential hazard to shipping lanes and offshore oil rigs, according to news reports.

1.   References

2.   Canadian Ice Service (2011, July 8). Petermann Ice Island Updates. Accessed July 28, 2011.

3.   Dunphy, M. (2011, July 26). Petermann Ice Island drifts within 10 km of Canada’s coast. Irish Weather Online. Accessed July 28, 2011.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response, NASA Goddard Space Flight Center. Caption by Michon Scott.

قدیمی ترین سنگواره ی حیوانا ت در سرزمین استرالیا پیدا شده است World's Oldest Animal Life - 650,000,000 Years Old

Primitive ocean sponges discovered in Australia could be the worlds oldest animal body fossils

Scientists may have discovered in Australia the oldest fossils of animal bodies. These findings push back the clock on the scientific world's thinking regarding when animal life appeared on Earth. The results suggest that primitive sponge-like creatures lived in ocean reefs about 650 million years ago. 

Rewriting the Fossil Record Book

 Below a cliff, a reddish bed is one of many stromatolite bioherms containing fossil sponges. Photograph by Adam Maloof, Princeton University.

The shelly fossils, found beneath a 635 million-year-old glacial deposit in South Australia, represent the earliest evidence of animal body forms in the current fossil record, predating other evidence by at least 70 million years. 

"These scientists have found that animals may have appeared on Earth 90 million years earlier than previously known," said H. Richard Lane of the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research. 

"This is comparable to resetting modern times to begin during the late Cretaceous." 

Previously, the oldest known fossils of hard-bodied animals were from two reef-dwelling organisms that lived around 550 million years ago. 

There are also controversial fossils of soft-bodied animals that date to the latter part of the Ediacaran period between 577 and 542 million years ago. 

Princeton University geoscientists Adam Maloof and Catherine Rose happened upon the new fossils while working on a project focused on the severe ice age that marked the end of the Cryogenian period 635 million years ago. 

رود ارس ، مرز بین ترکیه – ارمنستان - ایران Aras River, Turkey-Armenia-Iran Border Region

acquired July 8, 2011download large image (568 KB, JPEG)

This astronaut photograph, taken from the International Space Station, highlights a segment of the international border between Armenia and Turkey. The Aras River separates the two countries, with Armenia to the north-northeast and Turkey to the south-southwest. Extensive green agricultural fields are common on both sides of the river (image top), as well as a number of gray to tan urban areas including Artashat and Armavir in Armenia, and Igdir in Turkey. While there have been efforts to normalize diplomatic relations between the two countries in recent years, the Armenia-Turkey border remains officially closed.

The dominant geographic feature in the region is Mt. Ararat, also known as Agri Dagi. The peak of Ararat, a largestratovolcano that last erupted in 1840 according to historical records, is located approximately 40 kilometers (25 miles) to the south of the Armenia-Turkey border. A lower peak to the east, known as Lesser or Little Ararat, is also volcanic in origin. Dark gray lava flows to the south of Mt. Ararat are located near the Turkish border with Iran. While this border is also closed along much of its length, official crossing points allow relatively easy travel between the two countries.

The white, glacier-clad peak of Mt. Ararat is evident at image center; dark green areas on the lower slopes indicate where vegetation cover is abundant. A large lake, Balik Golu or Fish Lake, is visible to the west (image lower left).

Astronaut photograph ISS028-E-15023 was acquired on July 8, 2011, with a Nikon D2Xs digital camera using a 65 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 28 crew. The image in this article has been cropped and enhanced to improve contrast. Lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by William L. Stefanov, Jacobs/ESCG at NASA-JSC.

Instrument: 

ISS - Digital Camera

سپیده ی موشکی در نروژ Auroral Rocket in Norway

The aurora borealis and aurora australis—the northern and southern lights—are visible manifestations of a connection between the Sun and Earth. Blasts of energy and magnetically charged particles from the Sun are constantly flowing out into space and crashing into the magnetic fields of Earth and other planets. At Earth, that energy stirs up the particles and energy trapped in Earth’s space, or magnetosphere, creating the auroras and disturbing the upper reaches of our atmosphere.

Photographers captured these digital photos of a four-stage Black Brant XII sounding rocket and the aurora borealis (inset) on December 12, 2010, during the NASA-funded Rocket Experiment for Neutral Upwelling (RENU). The rocket was launched from Andøya Rocket Range near Andenes, Norway, and carried instruments about 200 miles (320 kilometers) into the atmosphere to observe the aurora and the associated flow of heat, particles, and electromagnetic energy. The photograph of the aurora was taken from the Kjell Henrickson Observatory in Svalbard, which was under the apogee, or peak, of the rocket’s arc through the sky. The rocket landed in the ocean about 900 miles (1450 km) from the launch site.

The goal of RENU was to measure the flow of particles and heat both into and out of Earth’s upper atmosphere near the North Pole during an auroral event. The solar wind stirs up Earth’s magnetic field and creates electrical currents in the ionosphere. Such disturbances can also heat the atoms of the thermosphere and other atmospheric layers, expanding them and creating extra drag on satellites and spacecraft, shortening their lifespan.

Around Earth’s poles, the magnetic field stretches out from the core of the planet into space and tucks back in at the opposite pole. The place where most of those field lines bunch up poke out of the Earth usually aligns in an auroral oval, where particles and energy from space precipitate and smash into the oxygen and nitrogen in the atmosphere to make the reds, greens, and whites of auroras. The funnel-shaped area inside that auroral oval—the polar cusp—is mostly open to space. RENU launched right into that cusp region to observe the flows of particles and energy both inbound and outbound.

1.   Further Reading

2.   Andøya Rocket Range (2010, December 12) Sounding Rocket Campaigns: RENU. Accessed January 3, 2011.

3.   Kjell Henrickson Observatory (2010, December 12). The Waiting Game. Accessed January 3, 2011.

4.   University of New Hampshire (n.d.) Magnetosphere-Ionosphere Research Lab. Accessed January 3, 2011.

5.   University of New Hampshire (2010, December 13) UNH-Led Experiment Hurtled Into Aurora Above Norway By NASA Rocket. Accessed January 3, 2011.

The ground-based photograph of the rocket was taken by Kolbjørn Blix Dahle of Andøya Rocket Range. The inset photo of the aurora was taken by Fred Signeres of The Kjell Henrickson Observatory. Caption by Michael Carlowicz.

Instrument: 

Photograph

ابر های درخشان شبانه تابناک تر می شوند Night-Shining Clouds are Getting Brighter

Increase of Polar Mesospheric Clouds, 1979–2010

After the Sun sets on a summer evening and the sky fades to black, you may be lucky enough to see thin, wavy clouds illuminating the night, such as these seen over Billund, Denmark, on July 15, 2010. Noctilucent or polar mesospheric clouds, form at very high altitudes—between 80 and 85 kilometers (50–53 miles)—which positions them to reflect light long after the Sun has dropped below the horizon. These “night-shining” clouds are rare—rare enough that Matthew DeLand, who has been studying them for 11 years, has only seen them once in person. But the chances of seeing these elusive clouds are increasing.

DeLand, an atmospheric scientist with Science Systems and Applications Inc. and NASA's Goddard Space Flight Center, has found that polar mesospheric clouds are forming more frequently and becoming brighter. He has been observing the clouds in data from Solar Backscatter Ultraviolet instruments that have been flown on satellites since 1978. The graph above shows how the brightness of the clouds has changed in the Northern Hemisphere. For reasons no one fully understands, the brightness wiggles up and down in step with solar activity, with fewer clouds forming when the Sun is most active. The biggest variability is in the far north. Underlying the changes caused by the Sun, however, is a trend toward brighter clouds. The upward trend in brightness, says DeLand, reveals subtle changes in the atmosphere that may be linked to greenhouse gases.

Polar mesospheric clouds are extremely sensitive to changes in atmospheric water vapor and temperature. The clouds form only when temperatures drop below -130 degrees Celsius (-200 Fahrenheit), when the scant amount of water high in the atmosphere freezes into ice clouds. This happens most often in far northern and southern latitudes (above 50 degrees) in the summer when, counter-intuitively, the mesosphere is coldest.

Changes in temperature or humidity in the mesosphere make the clouds brighter and more frequent. Colder temperatures allow more water to freeze, while an increase in water vapor allows more ice clouds to form. Increased water vapor also leads to the formation of larger ice particles that reflect more light.

The fact that polar mesospheric clouds are getting brighter suggests that the mesosphere is getting colder and more humid, says DeLand. Increasing greenhouse gases in the atmosphere could account for both phenomena. In the mesosphere, carbon dioxide radiates heat into space, causing cooling. More methane, on the other hand, puts more water vapor into the atmosphere because sunlight breaks methane into water molecules at high altitudes.

So far, it’s not clear which factor—water vapor or cooling—is causing polar mesospheric clouds to change. It’s likely that both are contributing, says DeLand, but the question is the focus of current research.

1.   References

2.   DeLand, M.T., Shettle, E.P., Thomas, G.E., and Olivero, J.J. (2007, May 30). Latitude-dependent long-term variations in polar mesospheric clouds from SBUV version 3 PMC data. Journal of Geophysical Research, 112, D10315.

3.   Shettle, E.P., DeLand, M.T., Thomas, G.E., and Olivero, J.J. (2009, January 17). Long term variations in the frequency of polar mesospheric clouds in the Northern Hemisphere from SBUV. Geophysical Research Letters, 36, L02803.

Photograph ©2010 Jan Erik Paulsen. Graph by Robert Simmon, adapted from Latitude-dependent long-term variations in polar mesospheric clouds from SBUV version 3 PMC data. Caption by Holli Riebeek.

January 27, 2011

ستاره شناسان بز رگترین مخز ن آب در فاصله ای بسیار دور را یافتند Astronomers Find Largest, Most Distant Reservoir of Water

Two teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe. The water, equivalent to 140 trillion times all the water in the world's ocean, surrounds a huge, feeding black hole, called a quasar, more than 12 billion light-years away.

"The environment around this quasar is very unique in that it's producing this huge mass of water," said Matt Bradford, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's another demonstration that water is pervasive throughout the universe, even at the very earliest times." Bradford leads one of the teams that made the discovery. His team's research is partially funded by NASA and appears in the Astrophysical Journal Letters.

A quasar is powered by an enormous black hole that steadily consumes a surrounding disk of gas and dust. As it eats, the quasar spews out huge amounts of energy. Both groups of astronomers studied a particular quasar called APM 08279+5255, which harbors a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns. 

Astronomers expected water vapor to be present even in the early, distant universe, but had not detected it this far away before. There's water vapor in the Milky Way, although the total amount is 4,000 times less than in the quasar, because most of the Milky Way's water is frozen in ice. 

Water vapor is an important trace gas that reveals the nature of the quasar. In this particular quasar, the water vapor is distributed around the black hole in a gaseous region spanning hundreds of light-years in size (a light-year is about six trillion miles). Its presence indicates that the quasar is bathing the gas in X-rays and infrared radiation, and that the gas is unusually warm and dense by astronomical standards. Although the gas is at a chilly minus 63 degrees Fahrenheit (minus 53 degrees Celsius) and is 300 trillion times less dense than Earth's atmosphere, it's still five times hotter and 10 to 100 times denser than what's typical in galaxies like the Milky Way.

Measurements of the water vapor and of other molecules, such as carbon monoxide, suggest there is enough gas to feed the black hole until it grows to about six times its size. Whether this will happen is not clear, the astronomers say, since some of the gas may end up condensing into stars or might be ejected from the quasar. 

Bradford's team made their observations starting in 2008, using an instrument called "Z-Spec" at the California Institute of Technology's Submillimeter Observatory, a 33-foot (10-meter) telescope near the summit of Mauna Kea in Hawaii. Follow-up observations were made with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA), an array of radio dishes in the Inyo Mountains of Southern California. 

The second group, led by Dariusz Lis, senior research associate in physics at Caltech and deputy director of the Caltech Submillimeter Observatory, used the Plateau de Bure Interferometer in the French Alps to find water. In 2010, Lis's team serendipitously detected water in APM 8279+5255, observing one spectral signature. Bradford's team was able to get more information about the water, including its enormous mass, because they detected several spectral signatures of the water. 

Other authors on the Bradford paper, "The water vapor spectrum of APM 08279+5255," include Hien Nguyen, Jamie Bock, Jonas Zmuidzinas and Bret Naylor of JPL; Alberto Bolatto of the University of Maryland, College Park; Phillip Maloney, Jason Glenn and Julia Kamenetzky of the University of Colorado, Boulder; James Aguirre, Roxana Lupu and Kimberly Scott of the University of Pennsylvania, Philadelphia; Hideo Matsuhara of the Institute of Space and Astronautical Science in Japan; and Eric Murphy of the Carnegie Institute of Science, Pasadena.

Funding for Z-Spec was provided by the National Science Foundation, NASA, the Research Corporation and the partner institutions. 

دستی بر خورشید Handle on the Sun

andle on the Sun
Date: 14 Sep 1999
This Extreme Ultraviolet Imaging Telescope (EIT) image of a huge, handle-shaped prominence was taken on Sept. 14,1999. Taken in the 304 angstrom wavelength, prominences are huge clouds of relatively cool dense plasma suspended in the Sun's hot, thin corona. At times, they can erupt, escaping the Sun's atmosphere

The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun's intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy.

سیلاب در سرزمین هند Flooding in India

From June to September each year, monsoon rains fall in southern Asia. The rains are crucial to agriculture, but at the same time pose hazards to crops, homes, and people. Floods often submerge fields, destroy buildings, and contaminate drinking water.

By late July 2011, the downside of monsoon rains was apparent in parts of India and Nepal, as both countries coped with displaced residents and casualties. This image shows estimated rainfall amounts from July 10 to 16, 2011. The lowest rainfall amounts (less than 50 millimeters, or 2 inches) appear in pale green, and the heaviest amounts (more than 400 millimeters, or 16 inches) appear in dark blue.

Floods and landslides result not just from rainfall but also from other factors such as land cover and topography. Places that receive less rain may actually suffer more serious consequences. Although this image shows higher precipitation levels in western India, some of the most severe damage reports came from the northeastern Indian state of Assam. On July 20, Hindustan Times reported that heavy rains washed out roads and breached embankments in that state. On July 18, AlertNet reported than hundreds of villages had been inundated.

Heavy precipitation caused trauma to other parts of the region as well. Heavy rains pushed dams to their limits in the western Indian state of Gujarat, according to Hindustan Times. Meanwhile, AlertNet reported that 73 people had died and another 25 were missing in Nepal. In India and Nepal, about 200,000 people had been forced from their homes.

The heavy rains in India and Nepal threatened to push rivers over their banks. The flood-prone Brahmaputra River was dangerously high, and authorities were watching the Kosi River, which abruptly changed course in 2008, in the wake of heavy rains.

This image is based on data from the Multisatellite Precipitation Analysis produced at Goddard Space Flight Center, which estimates rainfall by combining measurements from many satellites and calibrating them using rainfall measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite.

1.   References

2.   Das, B. (2011, July 18). More than 200,000 hit by floods in India, Nepal. AlertNet. Accessed July 21, 2011.

3.   HT correspondents. (2011, July 20). Brahmaputra above danger mark, Assam sounds alert. Hindustan Times. Accessed July 21, 2011.

NASA Earth Observatory image by Jesse Allen, using near-real-time data provided courtesy of TRMM Science Data and Information System at Goddard Space Flight Center. Caption by Michon Scott.

Instrument: 

TRMM - MPA