Technology

Volcanic activity has played a central role in forging the surface of Mercury, scientists have said.

MERCURY SHRINKING

Seven scientific instruments on the space probe Messenger sent back information about Mercury's magnetic field and about the fact that the extremely dense planet has been shrinking more than expected over the ages.


CAVE CLUES

Archeologists are opening a cave sealed for more than 30 years deep beneath a Mexican pyramid to look for clues about the mysterious collapse of one of ancient civilisation's largest cities. The soaring Teotihuacan stone pyramids, now a major tourist site about an hour outside Mexico City, were discovered by the ancient Aztecs around 1500AD, not long before the arrival of Spanish explorers.

SOLAR SQUASH?

The solar system may not be a round shape, but rather a bit squashed and oblong, according to data from the Voyager 2 spacecraft exploring the solar system's outer limits. Launched in 1977, the Voyager 1 and Voyager 2 unmanned probes are now studying the edges of the heliosphere, the huge magnetic 'bubble' around our solar system created by the solar wind as it runs up against the thin gas in interstellar space.

SOUND WOOD

Researchers using a medical scanner have worked out why a Stradivarius violin sounds so good – it is because of the remarkably even density of the wood. For the past 300 years, musicians and scientists have puzzled over the unparalleled quality of classical Cremonese violins made by Italian masters like Antonio Stradivari and Giuseppe Guarneri del Gesu.


POWERFUL BREW

A few cups of green tea each day may help prevent heart disease, Greek research shows. A study published in the European Journal of Cardiovascular Prevention and Rehabilitation showed further evidence of potential health benefits from a brew already linked to a reduced risk of cancers and other conditions.