An Italian environmental group warned on Monday that mass tourism is slowly eroding the Venice lagoon, which it said is also threatened by major real estate development and an inadequate transport network.

Architect Cristiano Gasparetto said a 1988 study indicated that while the acceptable maximum number of tourists for Venice is 33,000 daily, today the average figure is 59,000.

An international team of researchers using sophisticated x-ray technology has found chemical traces of a key color pigment in 100-million year old fossilized birds that once formed their feather patterns.

The study, reported Thursday in the journal Science, provides a glimpse into the biochemistry of prehistoric animals and greater understanding of their diets and environment.

Astronomers said on Wednesday they had snared light from a bright, ancient galaxy with a super-massive black hole at its core, a finding that would help explain aspects of the young Universe.

The phenomenon is called a quasar, which are very bright but very distant galaxies with a mighty black hole at their heart.

Modern conservationists could use gene analysis to better select endangered Tasmanian devils to capture in order to save the species from extinction, said a study on Monday.

The furry marsupials have been hit hard by a contagious cancer called devil facial tumor disease (DFTD) that has wiped out 70 to 90 percent of the population in some areas of its native Australia since it surfaced 15 years ago.

A frog with fangs, a blind snake and a round-headed dolphin are among more than 1,000 new species recently found on the incredible Melanesian island of New Guinea, environment group WWF said.

Scientists made the astounding discoveries, which also included a river shark and dozens of butterflies, on New Guinea at a rate of two a week from 1998 to 2008, WWF said in a new report on the island's natural habitat.

NASA says a newly discovered asteroid will have a close encounter with Earth on Monday, but there's no need to worry.

The space agency's Near-Earth Object Program Office says the small space rock — dubbed 2011 MD — will pass 7,500 miles (12,000 kilometers) above Earth's surface over the southern Atlantic Ocean at about 6:30 a.m. PDT (1330 GMT).

Campaigners in Japan are asking people to grow sunflowers, said to help decontaminate radioactive soil, in response to the Fukushima nuclear disaster that followed March's massive quake and tsunami.

Volunteers are being asked to grow sunflowers this year, then send the seeds to the stricken area where they will be planted next year to help get rid of radioactive contaminants in the plant's fallout zone.

A bone fragment at least 13,000 years old, with the carved image of a mammoth or mastodon, has been discovered in the southern U.S. state of Florida, a new study reports.

While prehistoric art depicting animals with trunks has been found in Europe, this may be the first in the Western Hemisphere, researchers report Wednesday in the Journal of Archaeological Science.

A strange moon of Saturn may have a salty ocean lurking beneath its iceball surface, according to a study appearing Wednesday in the British journal Nature.

The discovery comes from data from the U.S.-European orbiter Cassini, which has been touring the giant planet and its ring system since 2004.

The U.S. space agency said Tuesday it is sending a team of scientists on the second and final mission of a NASA field study of how melting Arctic ice is changing the life cycles of sea creatures.

The five-week mission, which kicks off Saturday, focuses on tiny organisms called phytoplankton, whose population blooms can offer clues about the wider health of the ocean ecosystem and how a warming climate may change the ocean's ability to absorb carbon from the atmosphere.