An exploding meteor was believed to be responsible for a huge bang that reverberated around the Pacific island nation of Niue last week, police said Monday.

Niue police chief Mark Chenery said the loud bang on Wednesday night woke the island's 1,200 residents and he initially thought a boat had exploded in the harbor.

In a spectacle that might have beguiled poets, lovers and songwriters if only they had been around to see it, Earth once had two moons, astronomers now think. But the smaller one smashed into the other in what is being called the "big splat."

The result: Our planet was left with a single bulked-up and ever-so-slightly lopsided moon.

A team of Ugandan and French paleontologists announced Tuesday they had found a 20-million-year-old ape skull in northeastern Uganda, saying it could shed light on the region's evolutionary history.

"This is the first time that the complete skull of an ape of this age has been found ... it is a highly important fossil and it will certainly put Uganda on the map in terms of the scientific world," Martin Pickford, a paleontologist from the College de France in Paris, told journalists in Kampala.

The first close-up pictures of the massive asteroid Vesta reveal a northern hemisphere littered with craters — including a trio nicknamed "Snowman" — and a smoother southern half, researchers reported Monday.

Running along the asteroid's equator are deep grooves — a surprise to scientists who did not expect to see such features.

The U.S. space agency plans to launch next week a solar-powered spacecraft called Juno that will journey to the gassy planet of Jupiter in search of how the huge, stormy giant was formed.

The $1.1 billion unmanned orbiter is scheduled for launch on August 5 -- the start of a five-year odyssey toward the solar system's most massive planet in the hopes that it will be able to circle Jupiter for a period of a year.

Earth is not alone in its orbit around the Sun - a small 'Trojan' asteroid sits in front of our planet and leads it, according to British science revue Nature, which published the discovery Thursday.

This diminutive asteroid has a diameter of just 300 meters but is called a Trojan because of its particular position in a stable spot either in front of a planet or behind it. Because the asteroid and planet are constantly on the same orbit, they can never collide.

One of the world's most famous fossil creatures, widely considered the earliest known bird, is getting a rude present on the 150th birthday of its discovery: A new analysis suggests it isn't a bird at all.

Chinese scientists are proposing a change to the evolutionary family tree that boots Archaeopteryx off the "bird" branch and onto a closely related branch of birdlike dinosaurs.

Scientists in Alaska said Tuesday they have figured out how to make squirrels hibernate, a process that could be used to preserve brain function in humans who suffer strokes or heart attacks.

But the technique only worked in squirrels who were awakened by researchers during their hibernation season, not outside normal hibernation times, said the study in The Journal of Neuroscience.

"Dirty Dozen" chemicals, including the notoriously toxic DDT, are being freed from Arctic sea ice and snow through global warming, a study published on Sunday suggested.

The "Dirty Dozen" -- formally known as persistent organic pollutants (POPs) -- were widely used as insecticides and pesticides before being outlawed in 2001.

Hong Kong physicists say they have proved that a single photon obeys Einstein's theory that nothing can travel faster than the speed of light -- demonstrating that outside science fiction, time travel is impossible.

The Hong Kong University of Science and Technology research team led by Du Shengwang said they had proved that a single photon, or unit of light, "obeys the traffic law of the universe".