Instead, the current Martian surface -- a cold, dusty and overwhelmingly dry place -- may have been the norm for much of the planet's history, scientists said during a briefing at the fall meeting of the American Geophysical Union.
Since NASA's 2001 Mars Odyssey satellite arrived in orbit around the planet, it has turned up evidence that there is lots of ice mixed in its soil, buried as little as 18 inches from the surface, said William Boynton, of the University of Arizona, Tucson.
Spread across the planet, the amount of water is not huge by Earth standards. In places, however, ice makes up 70 percent of the soil by volume, a significant concentration.
Previously, scientists speculated that large amounts of water once moved about Mars, falling as precipitation to the surface, where it flowed in rivers and streams to pool in lakes, perhaps even oceans.
Odyssey and the Global Surveyor have been remotely prospecting for the telltale traces of minerals that might have formed in such environments. Surveyor has found significant deposits of one such mineral, called hematite, at a location NASA may visit next year with a pair of rovers it intends to launch.
But Odyssey has yet to find other such minerals and has turned up minerals present in volcanic rocks that, on Earth at least, are quickly weathered by water. That suggests the water on Mars has largely stayed put. Even if it did flow on the surface of Mars, carving the river channels visible to this day, it probably only did so for brief periods of time.

Courtesy : The Science Journal

They have been described as a breakthrough in observational solar physics. The images show new solar features and hitherto unknown details in sunspots.
A striking feature in the images of sunspots is the existence of dark cores within bright filaments. This is an unexpected discovery and astronomers are uncertain what it signifies. The new observations realise a long-stated goal for solar observers to see the solar surface at a resolution better than 100 kilometres. It is believed that fundamental processes in the Sun's atmosphere take place on such scales.
To obtain the detailed view, the telescope's tube is evacuated and a mirror in the beam adjusts its shape a thousand times a second to counteract atmospheric blurring. Sunspots are regions with strong magnetic fields. A sufficiently large sunspot consists of a dark umbra, which is the coolest part of a sunspot, surrounded by a brighter penumbra. The penumbra appears to consist of thin, long filaments that have remained unresolved by solar telescopes until now.

Courtesy : journal Nature.

Researchers uncovered the extreme lake, called Lake Vida, along with 2,800-year-old microbes, under 19 metres of ice. Because the body of water has been cut off from the rest of the world for millennia, the scientists say it could represent a previously unknown type of ecosystem. This might make it an important template for the search for evidence of microbial life on other worlds, including Mars, they argue.
It had been thought Lake Vida was one of several Antarctic lakes that are frozen to their beds all year-round. But this new research shows otherwise. A team of US scientists extracted two ice cores above Lake Vida, which lies in a cold desert region of Antarctica known as the McMurdo Dry Valleys. They also used ground-penetrating radar to find liquid water below the lake's ice cap. The water remains liquid because it is seven times saltier than seawater and so will not freeze even at minus 10 Celsius - the temperature below the ice cover. The team did not drill directly into the lake for fear of contaminating it.
Using radiocarbon dating, the scientists analysed sediments found in the ice cores and dated them back 2,800 years. When the sediments were thawed, the scientists discovered micro-organisms which they successfully revived.This suggests that despite a complete lack of light, cold temperatures and hyper salinity, the lake itself may also contain life.

-Courtesy : The National Academy of Sciences,US.

To astronomers, flat means that the usual rules of geometry are observed - light not being bent by gravity travels in straight lines, not curves. But since Albert Einstein proposed that the Universe may be "curved", the debate has been open. Scientific opinion has moved towards a flat Universe and the latest data confirm this with greater certainty than ever before.
Another result of the study is the prediction that the Universe will continue its steady expansion, which started at the Big Bang, and will not collapse into a "Big Crunch".
The new information is an exquisitely accurate map of the very faint afterglow of heat left behind by the Big Bang. This is called the Cosmic Microwave Background (CMB) and is equivalent to the tiny warmth given off by something just a few degrees above absolute zero, -273 degC. Tiny temperature variations in the CMB, just 0.1% at most, allow scientists to test different models of how the Universe began and expanded.
The map paints a picture of the young Universe, just 300,000 years old - the cosmos is now over 12 billion years old. The chart was made by an international team led by Paulo de Bernardis of the University of Rome La Sapienza. The project to map the CMB was called Boomerang (Balloon Observations of Millimetric Extragalactic Radiation and Geophysics).

-Courtesy : The journal Nature & The US School of Natural Sciences, New Jersey,US.

One of our oldest ancestors crouches in a cave under African skies clutching a stone tool. The hominid, an early member of the human family, nicks itself and a drop of blood oozes on to the rock. Nearly two million years later, scientists detect microscopic traces of blood on the tool and extract the DNA. They say it is the oldest human genetic material ever found. This is the claim that is dividing the archaeological community. Two researchers say they have extracted the DNA of a 1.8-million-year-old hominid from stone tools excavated at the Sterkfontein Caves near Johannesburg.
The scientists believe that the DNA is that of either Homo habilis, thought to be a direct human ancestor, or Paranthropus robustus, a flat-faced hominid. If confirmed, it would be the oldest DNA yet extracted. Upright-walking creatures roamed the landscape at the site over three million years ago. In 1936, the first adult skull of Australopithecus africanus (2.6-3-million-year-old human-like creature) was discovered. Subsequent finds include stone tools and many hominid skulls and bones.

Courtesy : Wits University, South Africa & scientific journal .