The Tribune, Chandigarh, India

Rush to explore moon
Radhakrishna Rao

Possible presence of huge reserves of water and helium, a clean source of energy, on the surface of the moon is propelling many space-faring countries to explore the moon from fresh perspective.

As it is, scientists have already found traces of ice in the polar regions of the moon. These “traces” are expected to supply water to the futuristic missions to the moon.

No wonder then that the American space agency NASA has announced its plan to launch a two-ton probe that would crash into a carter on the moon in the hope of finding of water.

This $73-million lunar mission is planned to be launched in 2008. “We are going to learn a lot from this.

It is going to give us a definite understanding of what we have up there”, said a NASA researcher associated with the project.

NASA has also a plan up its sleeve for a series of robotic precursor missions, including the lunar crater observation spacecraft and sensing satellite or LCROSS which is designed to plow into the crater.

The innovative LCROSS probe is designed to hit the lunar crater and create a hole 16 ft deep and send up a plume of debris for sensors and imaging systems onboard a second monitoring spacecraft, situated some distance away. This monitoring satellite is planned to sweep through the plumes to collect and relay back data to earth.

The smart-1 lunar probe launched by the European Space Agency (ESA) in 2004 is known to have inaugurated what lunar scientists call “a golden age of lunar exploration”.

Meanwhile, both India and China are preparing to launch their own grown lunar probes during 2007-08. The Indian Chandrayaan-1 mission and China’s Chag’e mission have somewhat similar scientific objectives. In the context of the Beijing Olympics games, the launch of Chag’e has for China a significance that goes beyond just scoring a point in the area of cosmic research.

Indeed, for China, Chag’e would help brighten up its image as a front ranking scientific and technological power well at the time of Beijing Olympics.

Chinese space planners describe Chag’e as the first step towards a “deeper reach into space.”

G. Madhavan Nair, Chairman of ISRO looks at Chandrayaan-1 as a major step towards upgrading India’s technological capability and providing challenging opportunities to the younger generation for pursuing the planetary research.

As envisaged now, Chandrayaan-1 is expected to provide clues about the presence of water and helium on the lunar surface.

The Chandrayaan-1 probe will be launched by means of an augmented version of the highly successful Indian space vehicle Polar Satellite Launch Vehicle (PSLV) which features an alternate liquid and solid fuel stages.

For Chandrayaan-1 mission, the upper stage of PSLV described as the Indian space workhorse will be modified into a trans-lunar stage with about 2.2 tonne propellant.

The Chandrayaan-1 will take off from Satish Dhawan Space Centre in Sriharikota island on India’s eastern coast, about 100 km to the north of Chennai.

According to Madhavan Nair, Chandrayaan-1 will strive to unravel the hitherto unknown features of the moon for the first time. Though over the many years, probes have studied the lunar features from very close quarters, the origin and evolution of the moon continues to remain a mystery.

The Chandrayaan-1 spacecraft will be placed into 240-kmx24,000 km orbit and thereafter it will make use of its own propulsion system to reach the 100-km orbit around the moon.

The scientific objectives of Chandrayaan-1 also include physical and chemical mapping of the moon. In addition to six Indian payloads, Chandrayaan-1 will also carry scientific instruments contributed by the European Space Agency (ESA), Bulgaria and USA.

As it is, the remote sensing capability developed by ISRO over the years will be put to use to investigate the various features of the moon with the help of Chandrayaan-1 mission. For instance, a high resolution terrain mapping camera (TMC) with a stereo imaging capability operating in panchromatic band will map most of the moon’s surface and help in gaining insight into the origin and evolution of the moon.

A hyper spectral imager operating in 400-900 mm band with a low energy X-Ray fluorescent spectrometer will identify a variety of metallic elements in the entrails of the moon.

As it is, the focus of the mission would be on mineralogical and chemical mapping of the permanently shaded north and south polar regions of the moon.

On another front, ISRO is also serious about looking for surface water ice on the moon, specially at the lunar poles.

The Indian scientific community is of view that the availability of water — essential to sustain life — could fuel an international race to investigate the moon.

The possibility of frozen water existing on the moon, it is felt, could help set up a human base on the moon for planetary exploration.

Similarly, the abundant availability of helium, a clean source of energy, is yet another attraction to probe moon.

Scientific community in India is clear that an area that it needs to seriously pursue is the mining of helium and bringing it back to the earth for power generation.

To support the Chandrayaan-1 mission, ISRO is now in the process of setting up a deep space network.

200-year-old seeds germinate

A team of scientists from the Millennium Seed Bank in London have induced three species of almost 200-year-old seeds, which have been stored away since the time of George III, to germinate.

Brought to Britain from South Africa by a Dutch merchant in 1803, they were found in a notebook stored in the National Archives.

Given this history, the team of scientists says that their success has come as a surprise to them.

“They had been kept under pretty poor conditions,” BBC quoted Matt Daws, a seed ecologist with the Millennium Seed Bank, which is located at Wakehurst Place in West Sussex.

“They’d been in a ship for a year, certainly for months, coming back from the Cape; then they’d been kept in the Tower of London for a number of years. Only in the last 10 years have they been in controlled conditions. So I didn’t expect any of them to germinate and the three that did really are tough seeds,” he said.

The three successes made by Matt and his colleagues are a legume, Liparia villosa, and two species not yet identified, one a protea and the other an acacia.

While Liparia did particularly well, with 16 out of the 25 seeds progressing into plants, the acacia was a different proposition, says Matt.

“We only had two seeds to work with, and one of them turned out to have been eaten inside by an insect,” he said.

“What that means is we didn’t have many options - it was a shot in the dark as to whether we’d be able to get things to work,” he added.

He also said that his team has plans to make genetic and genomic analyses, and compare the old plants with modern-day equivalents, when they grow older. —ANI

Disappearing world
Michael McCarthy and David Usborne

Shorter winters mean Arctic polar bears struggle to build up enough reserves of fat to see them through summer

The melting of the sea ice in the Arctic, the clearest sign so far of global warming, has taken a sudden and enormous leap forward, in one of the most ominous developments yet in the onset of climate change.

Two separate studies by Nasa, using different satellite monitoring technologies, both show a great surge in the disappearance of Arctic ice cover in the last two years.

One, from the Jet Propulsion Laboratory in California, shows that Arctic perennial sea ice, which normally survives the summer melt season and remains year-round, shrank by 14 per cent in just 12 months between 2004 and 2005. The overball decrease in the ice cover was 720, 000 sq km (280, 000 sq miles) — an area almost the size of Turkey, gone in a single year.

The other study, from the Goddard Space flight Centre, in Maryland, shows that the perennial ice melting rate, which has averaged 0.15 per cent a year since satellite observations began in 1979, has suddenly accelerated hugely. In the past two winters the rate has increased to 6 per cent a year — that is, has got more than 30 times faster.

The changes are alarming scientists and environmentalists, because they far exceed the rate at which supercomputer models of climate change predict the Arctic ice will melt under the influence of global warming which is rapid enough.

If climate change is not checked, the Arctic ice will all be gone by 2070, and people will be able to sail to the North Pole. But if these new rates of melting are maintained, the Arctic ice will all be gone decades before that.

The implications are colossal. It will mean extinction in the wild — in the lifetime of children alive today — for one of the world’s most majestic creatures, the polar bear, which needs the ice to hunt seals.

It means the possibility of a lethal “feedback” mechanism speeding up global warming, because the dark surface of the open Arctic ocean will absorb the sun’s heat, rather than reflect it as the ice cover does now and so the world will get even hotter.

But most of all, the new developments add to the growing concern that climate change as a process is starting to happen much faster than such scientists considered it would, even five years ago when the UN’s Intergovernmental Panel on Climate Change published its last report.

“These are the latest in a long series of recent studies, all telling us that climate change is faster and nastier than we thought,” said Tom Burke, a former government green adviser and now a visiting professor at Imperial College, London. “An abyss is opening up between the speed at which the climate is changing and the speed at which governments are responding.

We must stop thinking that this is just another environmental problem, to be dealt with when time and resources allow, and realise that this is an increasingly urgent threat to our security and properity.”

— By arrangement with The Independent, London.

THIS UNIVERSE
PROF YASH PAL

Whatever be the colour of soap, the colour of lather is white. Why is it so?

Lather or foam is nothing but a collection of a large number of bubbles in which large amount of air is surrounded by extremely thin layers of watery liquid.

A large collection of these bubbles in the foam becomes a mechanism of creating a very large shiny surface over the soapy liquid using only a tiny amount of liquid.

Reflection and scattering by this surface becomes the dominant factor in the visibility of the froth. The colour of this froth then is about the same as the colour of the light incident on it. The incident light has little chance of interacting with the material that is used to make the foam.

Colour of the soap is hidden in the much larger reflection of light from the surface. Remember that when the room is bathed in red light the foam looks red and it looks green when the room has only green light.

It might be useful to look at the science of colours of soap bubbles that we can blow using a soap solution. In this case we do see varied colours of the spectrum. But these colours have nothing to do with soap or the material of which the soap is made. They are produced through interference of light waves reflected from the inner and outer layers of the bubble.

The origin of these colours lies in physical interaction and is independent of the chemical composition of the liquid used to blow them; no wavelength dependent energy absorption of the incident light is implicated.

The fact that we can see these colours implies that the thickness of the film cannot be more than a few wavelengths of light.

Do spiders drink water? If not, how do they quench their thirst?

You have asked me a question the answer to which I did not know. There is so much information that I do not have, or have forgotten. So I did the only thing possible for me. I searched the Internet. Some of what I gathered is the following:

There are thousands of species of spiders. Most of them do not have an active water drinking habit. They satisfy their need for fluid through eating their prey. In some others the very young, before they are separated from their mother drink dewdrops. Some of the species seem to eat a bit of their web fibre early morning while it’s still wet with the morning dew. Most spiders do not need to pee.

In the column published last week there was an inadvertent mistake.

In the second paragraph related to Coulomb force between positive and negative charges it should be:

“It is attractive between unlike charges and repulsive between like charges and varies........”

This has been wrongly reversed in the published column.