Sky-gazers around the world held up their telescopes and viewing glasses Wednesday to watch a once-in-a-lifetime event as Venus slid across the sun.

The transit began shortly after 2200 GMT Tuesday in parts of North America, Central America and the northern part of South America, and was visible, with magnification, as a small black dot on the solar surface.

A Hong Kong conservation group said Tuesday increasing high-speed ferry traffic is contributing to a dramatic decline in Chinese white dolphin numbers in the city's waters.

Research by the Hong Kong Dolphin Conservation Society showed that catamaran and jetfoil ferry traffic is displacing dolphins from their habitats in the mouth of the Pearl River Delta.

China said Tuesday foreign embassies were acting illegally in issuing their own air quality readings and that only the government could release data on the nation's heavy pollution.

China's cities are among the world's most polluted, but until recently, official air quality measurements regularly rated their air quality as good -- even as data from the U.S. embassy in Beijing showed off-the-chart pollution.

Two young cheetahs that escaped from an Austrian zoo overnight returned to their enclosure a few hours later, led home by their mother's calls, the zoo said Tuesday.

"Their mother called them and they followed her cries," said Christine Beck, a spokeswoman at the zoo located near Salzburg.

A Swiss adventurer took off Tuesday into the night skies above Madrid and headed for Rabat on the world's first intercontinental flight in a solar-powered plane.

Bertrand Piccard, 54-year-old psychiatrist and balloonist, piloted the Solar Impulse plane, a giant as big as an Airbus A340 but as light as an average family car, on the daring voyage from Europe to Africa.

When Venus next week eclipses Earth, an event that will not occur again for more than a century, millions of sky gazers may have romantic thoughts about our closest neighbor and its twilight beauty.

But the truth is that Venus is a hell that would have surpassed even the imagination of Dante, and it has caused more grief and disappointment than any other planet in the Solar System.

The prototype space shuttle that arrived in New York City by air earlier this spring is on the move again, this time by sea.

The Enterprise had been parked at Kennedy Airport since it flew from Washington to New York atop a 747 jet.

In the late eighth century, Earth was hit by a mystery blast of cosmic rays, according to a Japanese study that found a relic of the powerful event in cedar trees.

Analysis of two ancient trees found a surge in carbon-14 -- a carbon isotope that derives from cosmic radiation -- which occurred just in AD 774 and AD 775, the team report in the journal Nature on Sunday.

The French government is to ban a pesticide made by Swiss giant Syngenta used in rapeseed cultivation that has been found to shorten bees' lifespan, Agriculture Minister Stephane Le Foll said Friday.

"I have warned the group that sells Cruiser that I envisage withdrawing the licence to market," Le Foll said after the National Food, Environment and Work Safety Agency (ANSES) issued a damning report on the pesticide.

UNESCO on Saturday urged decisive action from Australia to protect the Great Barrier Reef from a gas and mining boom, warning it risked being put on its list of world heritage sites deemed "in danger".

Australia is riding an unprecedented wave of resources investment due to booming demand from Asia, with projects worth Aus$450 billion (U.S. $435 billion) in the pipeline.