Daily Archives: June 14, 2010

Northern hemisphere gullies on west-facing crater slope, Mars

This image shows the west-facing side of an impact crater in the mid-latitudes of Mars’ northern hemisphere. Image Credit: NASA/JPL-Caltech/University of Arizona

Six hundred recent observations of the Mars landscape from an orbiting telescopic camera include scenes of sinuous gullies, geometrical ridges and steep cliffs.

Each of the 600 newly released observations from the High Resolution Imaging Science Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter covers an area of several square miles on Mars and reveals details as small as desks.

The HiRISE images taken from April 5 to May 6, 2010, are now available on NASA’s Planetary Data System and the camera team’s website.

The camera is one of six instruments on NASA’s Mars Reconnaissance Orbiter, which reached Mars in 2006. For more information about the mission, see http://mars.jpl.nasa.gov/mro/.

Ancient Lava Plain in Thaumasia Planum

Ancient Lava Plain in Thaumasia Planum (PSP_002432_1525)
Credit: NASA/JPL/University of Arizona

This observation samples part of an ancient lava plain in Thaumasia Planum. The stack of lava flows has been folded into dunes the size of a chain of hills, as is visible in the center of the image.

The lava and the dunes has been degraded by erosion. The numerous craters and dunes attest to two of the erosional processes—meteorite impacts and the wind.

→ Leave a comment

Posted in Earth Weather Space

The Lazarus Project: Scientists Reconstruct the Genome of an Ancient Human

Posted on June 14, 2010 by thetruthbehindthescenes| Leave a comment

http://www.dailygalaxy.com/my_weblog/2010/02/the-lazarus-project-scientists-reconstruct-the-genome-of-an-extinct-human-.html

Scientists at the University of Copenhagen have become the first to reconstruct the first ancient human genome of a male who lived in Greenland 4,000 years ago and belonged to the first culture to settle in the New World Arctic. The innovative groundbreaking technique can be applied to museum materials and ancient remains found in nature and can help reconstructing human phenotypic traits of extinct cultures from where only limited remains have been recovered. It also allows for finding those contemporary populations most closely related to extinct cultures tracing ancient human expansions and migrations. Finally, the discovery improves our understanding of heredity and the disease risk passed down from our ancestors.

Gates of the Arctic Mountain Terrain

Professor Willerslev discovered the existence of the hair tuft by coincidence after several unsuccessful attempts to find early human remains in Greenland
“I was speaking with the Director of the Natural History Museum in Denmark, Dr. Morten Meldgaard, when we started discussing the early peopling of the Arctic,” Willerslev recalls. “Meldgaard who had participated in several excavations in Greenland told me about a large tuft of hair, which was found during an excavation in north-western Greenland in the 1980′s and now stored at the National Museum in Denmark.

The reconstruction serves as blueprint that scientists can use to give a description of how the pre-historic Greenlander, Inuk, looked – including his tendency to baldness, dry earwax, brown eyes, dark skin, the blood type A+, shovel-shaped front teeth, and that he was genetically adapted to cold temperatures, and to what extend he was predisposed to certain illnesses. This is important as besides four small pieces of bone and hair, no human remains have been found of the first people that settled the New World Arctic. Willerslev’s team can also reveal that Inuk’s ancestors crossed into the New World from north-eastern Siberia between 4,400 and 6,400 years ago in a migration wave that was independent of those of Native Americans and Inuit ancestors. Thus, Inuk and his people left no dependence behind among contemporary indigenous people of the New World.

“Previous efforts to reconstruct the mammoth nuclear genome resulted in a sequence filled with gaps and errors due to DNA damage because the technology was in its infancy. The genome of Inuk is comparable in quality to that of a modern human “, Willerslev tells and continues:

“Our findings can be of significant help to archaeologists and others as they seek to determine what happened to people from extinct cultures. Doing so requires organic material – bones or hair kept as museum pieces or found at archaeological sites. Previously, the DNA needed to have been frozen or buried in a layer of permafrost. But with the new methods developed here at the Centre, that is not a premise anymore”.

Much of the hands-on work analysing and joining the DNA sequences and the chemical analyses of what little was left of the damaged genetic material together to form a complete profile of Inuk was done by Morten Rasmussen. The work was carried out in close collaboration with other scientists at the University of Copenhagen and in China, where they have far more sequencing machines than in Denmark.

“Not so long ago, reconstructing an entire modern human genome took years,” Rasmussen says. But the new methods and the abundance of sequencing machines allow us to do it in just a few months – and that includes the time-consuming task of analysing the results. The interesting thing about compiling a human genome is that we can look at the genes to see traits like why Scandinavians are blonde, why some are predisposed to certain illnesses and why others more easily become addicted to alcohol or tobacco. But the genome we’ve reconstructed is no Frankenstein’s Monster; it’s more like we’ve got the blueprints for a house, but we don’t know how to build it.”

The results of the team’s research will be published in the leading British scientific journal Nature.

http://news.ku.dk/all_news/2010/2010.2/human_genome/

→ Leave a comment

Posted in Ancient Civilizations

The red plains of Mars were once covered by a vast ocean… and lush planet could have supported extra-terrestrial life

Posted on June 14, 2010 by thetruthbehindthescenes| Leave a comment

http://www.dailymail.co.uk/sciencetech/article-1286370/The-red-plains-Mars-covered-vast-ocean.html

A vast ocean once covered a third of the surface of Mars, scientists revealed last night.

Far from being a dusty red desert, our neighbouring planet was once wet and rainy – raising the prospect that it was home to extra-terrestrial life.

The ocean stretched across 36 per cent of the red planet around 3.5 billion years ago and contained 30million cubic miles of water.

Life-sustaining: The ocean and shoreline of Mars as it might have looked 3.5billion years ago

Life-sustaining: The ocean and shoreline of Mars as it might have looked 3.5billion years ago

The discovery is based on a detailed study of the dried-up river deltas and thousands of river valleys that scatter the Martian surface.

Scientists from the University of Colorado at Boulder are unsure why the water vanished, but many suspect traces of the ocean remain in ice buried deep beneath the surface.

Dr Brian Hynek, who took part in the study published in the journal Nature Geoscience, said Mars probably once had a water cycle like the Earth’s – with rain falling into rivers and oceans, evaporating into the atmosphere and forming clouds.

The Martian sea – which has not been named – contained around a tenth of all the water found in Earth’s oceans, he said. Mars is slightly more than half the size of Earth.

Long lived oceans may have teemed with microbes at a time when the life is thought to have also been starting on Earth.

Vast: Mars's northern hemisphere ocean may have held 10 times more water than all the Earth's, research suggests

Vast: Mars’s northern hemisphere ocean held 10 times more water than all the Earth’s, research suggests

Barren: Dry and dusty, how Mars looks today

Barren: Dry and dusty, how Mars looks today

Using detailed maps of Maps created by orbiting Nasa and European Space Agency spacecraft, the researchers looked at the remains of 52 river deltas, each fed by numerous river valleys.

More than half were at the same altitude and appeared to mark the boundaries of a massive ocean. The amount of water in the ocean would have formed the equivalent of a 1,800 foot layer spread out over the entire planet.

Co-author Dr Gaetano Di Achille said: ‘On Earth, deltas and lakes are excellent collectors and preservers of signs of past life. If life ever arose on Mars, deltas may be the key to unlocking Mars’ biological past.’

A second study also detected around 40,000 river valleys – four times more than have previously been spotted.

The valleys were the source of sediment that was carried downstream and dumped into the deltas.

Dr Hynek said: ‘The abundance of these river valleys required a significant amount of precipitation.’

The idea of a large ancient ocean on Mars has been debated for two decades. However, the new study provides compelling evidence that the sea existed – and raises tantalising questions about the planet’s history.

‘One of the main questions we would like to answer is where all of the water on Mars went,’ said Dr Di Achille.

Future Mars missions – including NASA’s Mars Atmosphere and Volatile Evolution project, due to blast off in 2013, should shed light n the mystery.

→ Leave a comment

Posted in Earth Weather Space