Reef sharks have dropped sharply near populated islands in the Pacific Ocean, scientists said Friday.

The survey by the University of Hawaii showed that the numbers were drastically lower near populated islands in Hawaii, the Mariana Archipelago and American Samoa, compared to more pristine, remote areas in the ocean.

In a city understandably wary of low-flying aircraft, New Yorkers and tourists alike watched with joy and excitement Friday as space shuttle Enterprise sailed over the skyline on its final flight before it becomes a museum piece.

Ten years after 9/11, people gathered on rooftops and the banks of the Hudson River to marvel at the sight of the spacecraft riding piggyback on a modified jumbo jet that flew over the Statue of Liberty and past the skyscrapers along Manhattan's West Side.

European scientists said Friday they had detected a subatomic particle that sheds light on one of the basic forces of nature which determines the structure of matter.

The particle, a baryon called Xi_b, cannot be detected directly as it is too unstable, but scientists observed traces of it in a test at the European Organization for Nuclear Research's Large Hadron Collider (LHC).

A DNA analysis of four Stone Age humans in Europe published Thursday reveals how farmers likely migrated northward from the Mediterranean and eventually bred with hunter-gathers.

The research, by a Swedish-Danish team and published in the U.S. journal Science, sheds light on an oft-debated chapter of human history -- how did agriculture spread from the Middle East to Europe?

An Australian study of ocean salinity over the past 50 years has revealed a "fingerprint" showing that climate change has accelerated the rainfall cycle, according to a researcher.

The study published in the journal Science and conducted by Australian and U.S. scientists looked at ocean data from 1950 to 2000 and found that salinity levels had changed in oceans around the world over that time.

After two decades of examining a microscopic algae-eater that lives in a lake in Norway, scientists on Thursday declared it to be one of the world's oldest living organisms and man's remotest relative.

The elusive, single-cell creature evolved about a billion years ago and did not fit in any of the known categories of living organisms -- it was not an animal, plant, parasite, fungus or alga, they said.

Lava flows carved valleys on Mars, U.S. scientists said Thursday amid a long-running debate over whether water or volcanoes formed part of the red planet's landscape.

The lava left behind telltale coils as seen on some parts of Earth, like on the Big Island of Hawaii and in submarine lava flows near the Galapagos Rift on the floor of the Pacific Ocean, said the findings in the journal Science.

Antarctica's massive ice shelves are shrinking because they are being eaten away from below by warm water, a new study finds. That suggests that future sea levels could rise faster than many scientists have been predicting.

The western chunk of Antarctica is losing 23 feet of its floating ice sheet each year. Until now, scientists weren't exactly sure how it was happening and whether or how man-made global warming might be a factor. The answer, according to a study published Wednesday in the journal Nature, is that climate change plays an indirect role — but one that has larger repercussions than if Antarctic ice was merely melting from warmer air.

Physicists in the United States said Wednesday they have developed a simulator that will allow them to observe the behavior of subatomic particles impossible to measure on existing computers.

Understanding quantum mechanics is a key challenge for scientists seeking to explain natural phenomena on the subatomic level, where the laws of nature work differently to those of the observable world.

Scientists studying bats have found dozens of new members of a virus family linked to human disease, and warned of possible exposure as the winged mammals are driven out of forests into the cities.

Sixty-six new species of paramyxoviruses, the viral group that causes measles and mumps and is behind three cattle diseases, have a natural host in bats, they said.