The U.S. space agency said Tuesday it is launching a second investigation into a leaking helmet that forced an abrupt halt to an Italian astronaut's spacewalk last week.

The probe will examine maintenance, quality assurance, and any operations that could have had a role in the gushing water that mysteriously appeared in the helmet of Italian spacewalker Luca Parmitano.

Mexican paleontologists say they have uncovered 50 vertebrae believed to be a full dinosaur tail in the northern desert of Coahuila state.

The National Institute of Anthropology and History says the tail is about 15 feet (5 meters) long and resembles that of a hadrosaur or crested duckbill dinosaur.

More than half of Europe's main species of grassland butterflies are in sharp decline as a result of habitat loss, the European Environment Agency (EAA) warned on Tuesday.

"Butterfly populations have declined by almost 50 percent, indicating a dramatic loss of grassland biodiversity," it said.

Wild bottlenose dolphins design unique signature whistles to identify themselves, and they answer when a close cohort calls them by name, researchers said Monday.

A study of 200 bottlenose dolphins off the eastern coast of Scotland found that they are the only non-human mammals to use the names of those in their close circles to get each other's attention.

A towering plant that smells like rotting meat and is native to the Indonesian rainforest was in full bloom in the U.S. capital on Monday, drawing throngs of tourists.

The titan arum, among the world's largest plants, began blooming on Sunday at the United States Botanic Garden, and its petals are expected to stay open for just 24 to 48 hours.

A major Chinese state-owned coal producer has caused "drastic drops" in groundwater near one of its projects, the environmental group Greenpeace said in a report Tuesday.

Lakes have shrunk, wells have dried and sand dunes are spreading near a plant in Inner Mongolia run by coal conglomerate Shenhua Group, the organisation said.

Scientists on Sunday sparked a fresh debate over what triggered Indonesia's Lusi mud volcano, still spewing truckloads of slime more than seven years after it leapt catastrophically into life.

Published in the journal Nature Geoscience, the study strengthens the argument by gas company PT Lapindo Brantas that the disaster was caused by a distant earthquake, not by its drilling crew as some experts contend.

Within 50 years, climate change will probably wipe out the world's most endangered feline, the Iberian lynx, even if the world meets its target for curbing carbon emissions, biologists said on Sunday.

The gloomy forecast, published in the journal Nature Climate Change, says that without a dramatic shift in conservative strategy, the charismatic little wildcat seems doomed.

Smile Earth! You're on camera.

NASA is inviting the public to look skyward and wave at Saturn and Mercury in what is billed as an interplanetary photo op.

After a quarter-century of searching, scientists have nailed down how one particularly rare subatomic particle decays into something else — a discovery that adds certainty to our thinking about how the universe began and keeps running.

The world's top particle physics lab said Friday it had measured the decay time of a particle known as a Bs (B sub s) meson into two other fundamental particles called muons, which are much heavier than but similar to electrons. It was observed as part of the reams of data coming from CERN's $10 billion Large Hadron Collider, the world's largest atom smasher, on the Swiss-French border near Geneva.