The US has already said it plans to build a new lunar spacecraft to succeed the last Apollo mission in 1972.

Funds will be moved from space shuttle flights, due to be scrapped in 2010.

The structure of the base and the exact duties of the astronauts stationed there have not been decided.

Nor is it clear when the base will begin functioning.

Lunar outpost

"We're going for a base on the moon," Scott "Doc" Horowitz, Nasa's associate administrator for exploration, said.

The agency's deputy head, Shana Dale, is quoted by the Associated Press news agency as saying that the "fundamental lunar approach" will be very different to earlier Moon missions.

Nasa has elected to build a lunar outpost rather than operate brief trips to the satellite as it did in the 1960s.

Nasa is also expected to ask other countries - and businesses - to help it build the base.

The permanent base will be built near one of the two poles, as these are felt to have a moderate climate and more sunlight - essential if the base is to use solar energy.

"It's exciting," Shana Dale told the Reuters news agency. "We don't know as much about the polar regions."

According to Reuters, funds for building the lunar base will be diverted from the space shuttle programme, which is to be phased out by 2010.

After the Columbia space shuttle accident, US President George W Bush announced plans to send astronauts back to the moon by 2020.

Nasa announced in August that the Lockheed Martin Corporation will build the next US spaceship to take humans to the Moon.

Durian later crossed the Mekong Delta, which as a low-lying area is at high risk of flooding.

The same storm caused devastation in the Philippines, triggering mudslides which killed hundreds of people.

The official toll from the mudslides, which struck near the Mayon volcano south-east of Manila and engulfed villages, stands at 520 people. Another 750 are missing.

Forcible evacuation

The BBC's Bill Hayton, in Hanoi, says the government's decision to authorise local authorities to take all the means necessary to move people from the path of the storm may have saved lives.

But, he says, though thousands left voluntarily, many were forcibly removed from their homes.

He says it is highly unusual for southern Vietnam to experience such a storm in the month of December.

Communication with the island of Phu Qui, some 250km (150 miles) east of Ho Chi Minh City, had been lost, officials said.

Over 1,000 homes were damaged and more than 800 fishing boats swept away from their anchors on the island, according to the Associated Press.

The meteorite, larger than Table Mountain, caused a thousand-megaton blast of energy. The impact would have vaporised about 70 cubic kilometres of rock - and may have increased the earth's oxygen levels to a degree that made the development of multicellular life possible.

The world has about 130 crater structures of possible impact origin. The Vredefort Dome is among the top three, and is the oldest and largest clearly visible meteorite impact site in the world.

The original crater, now eroded away, was probably 250 to 300 kilometres in diameter. It was larger than the Sudbury impact structure in Canada, about 200km in diameter.

At 2-billion years old, Vredefort is far older than the Chixculub structure in Mexico which, with an age of 65-million years, is the site of the impact that led to the extinction of the dinosaurs.

Vredefort's original impact scar measures 380km across and consists of three concentric circles of uplifted rock. They were created by the rebound of rock below the impact site when the asteroid hit. Most of these structures have eroded away and are no longer clearly visible.

The inner circle, measuring 180km, is still visible and can be seen in the beautiful range of hills near Parys and Vredefort. It is this area that was named a World Heritage site.

Internationally, there are 812 World Heritage sites, in 137 countries. Africa has 65 sites and South Africa now a total of seven - three cultural, three natural and one of mixed cultural and natural heritage. The Vredefort Dome is a natural heritage site.

South Africa's other six World heritage sites are Robben Island, the Greater St Lucia Wetlands Park, the Mapungubwe Cultural Landscape, the Cradle of Humankind, the uKhahlamba Drakensberg Park and the Cape Floral Region.

"The Vredefort site is rich in the symbolic representation of our culture; it demonstrates the meeting between scientific and cultural philosophy and practice," Arts and Culture Minister Pallo Jordan said after the inscription of the site on the World Heritage list.

"At Vredefort, opportunities exist to engage in geological research and explore and understand more sensitively the rich culture of the Basotho, Batswana and Khoi-San and the early evidence of human cognitive and artistic endeavour their cultures boast.

"This demonstrates that heritage can be a tool for nation-building."

The Vredefort Conservancy

Further evidence of the meteorite impact site can be seen in the columns of granite that were injected into existing rock by the force and heat of impact.

In 1937, earth scientists John Boon and Claude Albritton Boon were the first to suggest that the Vredefort structure was the scar of an ancient meteorite impact. Since then the site has been studied extensively by earth scientists from around the world.

The Vredefort Dome Conservancy, as it is now known, is not just of scientific value. It also has great scenic beauty, making it an ideal tourist destination.

The Dome Conservancy contains a finely balanced ecosystem made up of open plains, bushveld, mountains and ravines with abundant flora and fauna. At least 99 plant species have already been identified, of which the world's largest olive wood tree forest is probably the best known.

The area is considered an important birding area, with over 450 species already identified. It also has as many identified butterflies as the whole of Great Britain, and is home to rare animals such as the rooikat, aardwolf, leopard and the endangered rock dassie.

The Department of Environmental Affairs and Tourism plans to spend R18-million on tourism and infrastructural development at the site - including the eradication of alien invasive vegetation, creation of hiking trails and construction of a tourism centre.

The Vredefort Dome site fulfils all the criteria set by Unesco for a World Heritage site. It is of outstanding universal value from a scientific point of view, and is remarkable evidence of an important moment in the earth's geologic history.

Shiveluch, the northernmost active volcano on Kamchatka, is the second to erupt on the Pacific peninsula in two days.

Local emergency services reported Monday that the Karymsky volcano has increased its activity, spewing ash up to an altitude of 6,900 meters (22,637 feet).

Karymsky is one of Kamchatka's most active volcanoes, and rises to 1,486 meters (4,875 feet) above sea level in the southeast part of the peninsula.

According to experts, there are more that 150 volcanoes on Kamchatka, 29 of them active.