A dead NASA satellite will soon fall to Earth, but the space agency says there is very little chance that a piece of it will hit someone.

NASA says the 20-year-old satellite will probably fall sometime between late September and October. Pieces of it could land anywhere in the six inhabited continents in a worldwide swath from south of Juneau, Alaska, to just north of the tip of South America. NASA scientists estimate a 1-in-3,200 chance a satellite part could hit someone. Most of it will burn up after entering Earth's atmosphere.

Were it not for meteorites striking Earth some four billion years ago, humans would never have laid eyes on the gold that has raised and ruined civilizations, according to a study published Thursday.

Two hundred million years earlier, during the violent throes of planetary formation, Earth was a mass of molten minerals set afire by collisions with planet-sized heavenly bodies.

It's more than 40 years since Neil Armstrong became the first man to walk on the Moon, but his memories of the historic flight remain as undimmed as his passion for further exploration of space.

The Apollo 11 commander, now aged 81, relived the 1969 mission that enthralled the world as he watched Google's new high-definition images of the Moon in Australia last week.

Space junk has made such a mess of Earth's orbit that experts say we may need to finally think about cleaning it up.

That may mean vacuuming up debris with weird space technology — cosmic versions of nets, magnets and giant umbrellas, according to the chairman of an expert panel that issued a new report on the problem Thursday.

A 3.6-million-year-old woolly rhinoceros fossil discovered in Tibet indicates that some giant mammoths, sloths and saber-tooth cats may have evolved in highlands before the Ice Age, experts say.

Paleontologists from the Natural History Museum of Los Angeles County and the Chinese Academy of Sciences, who found the rhino's complete skull and lower jaw in 2007, argue that it adapted to the global cooling before it happened.

A glitter in the sky caught their eye, and astronomers have documented what they believe is the first tiny planet made of diamond some 4,000 light years away, according to a study published Thursday.

The discovery of the small, fast-spinning gem world that has more mass than the gas giant Jupiter was made by an international team of researchers who published their findings in the journal Science.

Russia has grounded its Soyuz rockets after one of the unmanned craft crashed shortly after blast-off while carrying tons of cargo for the International Space Station, a space official said Thursday.

"A decision has been taken to halt the launch of Soyuz carrier rockets until the reasons for the accident become clear," the unnamed Russian official told the Interfax news agency.

Our world is a much wilder place than it looks. A new study estimates that Earth has almost 8.8 million species, but we've only discovered about a quarter of them. And some of the yet-to-be-seen ones could be in our own backyards, scientists say.

So far, only 1.9 million species have been found. Recent discoveries have been small and weird: a psychedelic frogfish, a lizard the size of a dime and even a blind hairy mini-lobster at the bottom of the ocean.

A bio-art project to create bulletproof skin has given a Utah State researcher even more hope his genetically engineered spider silk can be used to help surgeons heal large wounds and create artificial tendons and ligaments.

Researcher Randy Lewis and his collaborators gained worldwide attention recently when they found a commercially viable way to manufacture silk fibers using goats and silkworms that had spider genes inserted into their makeup.

International scientists searching to solve the greatest riddle in all of physics said Monday that signs are fading of the elusive Higgs-Boson particle, which is believed to give objects mass.

Just last month, physicists announced at a European conference that a big atom-smasher experiment had shown tantalizing hints of the Higgs-Boson, as the search to identify the particle enters the final stretch with results expected late next year.