Kaali, on the Estonian island of Saaremaa, is the site of the last giant meteorite impact to occur in a densely populated region. The landscape that the collision left in its aftermath has been the subject of many mythological tales and may have been home to a mysterious ancient cult.

About 7,500 years ago, a huge rock from space came hurtling toward the earth, faster than a speeding rocket. Several kilometers above the earth's surface, the meteorite broke into pieces from the pressure and heat of the atmosphere. The resulting chunks collided into Saaremaa with the force of a small nuclear bomb, wreaking havoc on the landscape and possibly claiming numerous victims.

The explosion left nine total craters, now known as the Kaali Meteorite Crater Field. Some of these craters are quite small: one measures only twelve meters across and one meter deep. But the most interesting of the group is the largest crater, a gently sloping bowl filled with stagnant, murky water.

Simply known as Kaali crater, the largest crater (which measures 110 meters across) is believed to have been a sacred site for many centuries, in part due to its cosmic origin. Surrounding Kaali crater are the remains of an immense stone wall from the Late Bronze Age, stronger than any similar structures in the region and providing clues to the crater's use by ancient peoples.

Since the dawn of civilisation, man has been asking questions such as 'who are we?' and 'where have we come from?' Until 1858 it was universal belief that man is special creation of God. In 1858, based on phenotypic transition of various organisms including plant and animal species, Charles Darwin proposed the theory of evolution and wrote a book The Origin of Species. Eight years later in 1871, he wrote a book The Descent of Man. Based on the anatomical similarities, he declared that the chimpanzee and the gorilla are our closest living relatives and predicted that the earliest ancestors of humans would turn up in Africa, where our ape kins live today.

Now it is widely accepted view that modern human diverged from a common ancestor of chimpanzee and human nearly 6-7 million years ago. Based on fossil records found in Africa, it is now believed that modern human originated from a single mother about 160,000 years ago in East Africa. East-African mega-droughts between 135 and 75 thousand years ago, when the water volume of the lake Malawi was reduced by at least 95 per cent, could have caused their migration out of Africa. The obvious question to ask is which route did they take? Our study of the tribes of Andaman and Nicobar Islands using complete mitochondrial DNA sequences, and its comparison with the mitochondrial DNA sequences of the world populations available in the database, led to the theory of southern coastal route of migration through India, against the prevailing view of northern route of migration via Middle East, Europe, south-east Asia, Australia and then to India. Our earlier study revealed that Negrito tribes of Andaman and Nicobar Islands, such as Onge, Jarawa, Great Andamanese and Sentinelese, are probably the descendants of the first man who moved out of Africa.

This raised many questions such as: (i) what is the origin of mainland tribal and caste populations?; (ii) are there any population(s) in mainland India, which are close to Andamanese?; (iii) how much affinities the Indian populations have with Andamanese?; (iv) did the Indians contribute to the early human spread?

In order to answer these questions and to explore the ancient history of India we have harnessed genomic technology.

The collapse of the Earth's magnetic field, which both guards the planet and guides many of its creatures, appears to have started in earnest about 150 years ago. The field's strength has waned 10 to 15 percent, and the deterioration has accelerated of late, increasing debate over whether it portends a reversal of the lines of magnetic force that normally envelop the Earth.

During a reversal, the main field weakens, almost vanishes, then reappears with opposite polarity. Afterward, compass needles that normally point north would point south, and during the thousands of years of transition, much in the heavens and Earth would go askew.

A reversal could knock out power grids, hurt astronauts and satellites, widen atmospheric ozone holes, send polar auroras flashing to the equator and confuse birds, fish and migratory animals that rely on the steadiness of the magnetic field as a navigation aid. But experts said the repercussions would fall short of catastrophic, despite a few proclamations of doom and sketchy evidence of past links between field reversals and species extinctions.

Although a total flip may be hundreds or thousands of years away, the rapid decline in magnetic strength is already damaging satellites.

Two potential signatures of life on Saturn's moon Titan have been found by the Cassini spacecraft. But scientists are quick to point out that non-biological chemical reactions could also be behind the observations.

Titan is much too cold to support liquid water on its surface, but some scientists have suggested that exotic life-forms could live in the lakes of liquid methane or ethane that dot the moon's surface.

In 2005, Chris McKay of NASA's Ames Research Center in Moffett Field and Heather R Smith of the International Space University in Strasbourg, France, calculated that such microbes could eke out an existence by breathing in hydrogen gas and eating the organic molecule acetylene, creating methane in the process.

Scammers are distributing apps for Windows Mobile-based smartphones that have malware hidden inside that makes calls to premium-rate numbers across the globe, racking up expensive bills unbeknownst to the phone's owner, a mobile security firm said on Friday.

The apps--3D Anti-Terrorist game, PDA Poker Art, and Codec pack for Windows Mobile 1.0--are being distributed on as many as nine popular download Web sites, including DoDownload, GearDownload, and Software112, according to John Hering, chief executive and founder of mobile security provider Lookout.

Company promises to go legit with RemoteSpy tool

The US Federal Trade Commission (FTC) has agreed to settle a case with CyberSpy Software, the vendor of the popular RemoteSpy key-logging tool.

The company and its owner had been accused of pushing RemoteSpy as an " undetectable" tool which could be disguised as another type of file and used to gather data without the target's knowledge.

Receiver upgrade gone bad

As many as 10,000 global positioning system receivers were rendered useless for days as a result of a software upgrade in January that didn't go well, the Associated Press reports.

The "compatibility issue" affected 8,000 to 10,000 of the military's 800,000 GPS receivers, although officials didn't say how many weapons, planes, or other systems were affected or if any of them were in use in Iraq or Afghanistan. An Air Force document said a jet-powered carrier-based drone still under development was interrupted by the glitch.

Scientists in Russia launched an ambitious Mars spaceflight simulation Thursday - one that will lock six volunteers away for a record-setting 520 days to practice every step of a mission to the red planet without ever leaving Earth.

The Mars500 project, a joint experiment by Russia, the European Space Agency and China, began at 5:49 a.m. EDT (0949 GMT) as the hatches to the mock Mars spaceship were shut at Russia's Institute for Biomedical Problems (IBMP) in Moscow. Three Russians, two Europeans and one Chinese volunteer make up the experiment's six-man crew.

"Goodbye Sun, goodbye Earth, we are leaving for Mars!" wrote French engineer Romain Charles, one of ESA's two crewmembers in the simulation, in a mission diary on Wednesday.

When Karl Aston saw a fireball in the sky, his first thought was of chasing it.

The St. Louis research chemist, whose in-laws live in Quincy, hunts for and collects meteorites in his spare time. After a meteorite streaked across the night sky on April 14 as a brilliant fireball visible to the naked eye across the Upper Midwest, Aston traveled to its landing place in rural southwest Wisconsin and found one of the largest discovered chunks of the rock.

Scientists are thrilled by discoveries like Aston's, pointing to the modern rarity of visible meteorites and the clues about space and Earth their remnants provide.

"This is really top-notch science," said Gregg Maryniak, director of the St. Louis Science Center's James S. McDonnell Planetarium, which will display Aston's meteorite chunk later this summer.

Aston took up meteorite hunting and collecting three years ago. He has since networked with many other meteorite hunters around the country, developing "a lot of camaraderie and friendly competition" with them.

A thick haze of organic material let the early Earth soak up the sun's warmth without absorbing harmful ultraviolet rays, according to a new study.

The model offers a new twist on an old puzzle: Although the sun was so dim billions of years ago that the Earth should have been a ball of ice, the young planet had liquid oceans capable of supporting life.

"Given these recent papers, we can probably say the early faint sun problem is not one of the problems anymore in solving the origin of life," said astrophysicist Christopher Chyba of Princeton University, who was not involved in the new work.

The sun should have been up to 30 percent less bright 3.8 billion to 2.5 billion years ago, according to studies of the lifecycles of sun-like stars. If the Earth's atmosphere had the same composition then as it does now, it would have frozen over completely, like Jupiter's moon Europa. But geological records show the Earth was at least as warm and wet then as it is today.