SCIENCE TRIBUNE Thursday, March 1, 2001, Chandigarh, India

Rendezvous with an asteroid
Miraculous landing on Eros 433
D.P. Singh
ear spacecraft became a part of history as mankind’s first robot visitor to an asteroid when it settled onto the rocky surface of Eros 433. The exotic event occurred shortly after 2000 GMT on Feb 12, 2001. NEAR is already in the record books as the first ever spacecraft to go into orbit around any asteroid, the first to operate on solar power so far from the sun, and the first ever to conduct an in-depth study of an asteroid.

Sweet healing through honey
Harender Raj Gautam
or treating your wounds, you can skip surgery and swallowing of bulk of antibiotics. In future, when you visit a doctor for treating your wounds he may offer you a poultice of honey. Honey has been used to treat wounds for millennia. In the First World Wound Healing Congress held at Melbourne in September, 2000, researchers deliberated on a significant finding that honey has outperformed antibiotics in treating wounds and even Caesarean sections and burns. 


Science Quiz
J. P. Garg tests your IQ 



Rendezvous with an asteroid
Miraculous landing on Eros 433
D.P. Singh

Near spacecraft became a part of history as mankind’s first robot visitor to an asteroid when it settled onto the rocky surface of Eros 433. The exotic event occurred shortly after 2000 GMT on Feb 12, 2001. NEAR is already in the record books as the first ever spacecraft to go into orbit around any asteroid, the first to operate on solar power so far from the sun, and the first ever to conduct an in-depth study of an asteroid.

NEAR (Near Earth Asteroid Rendezvous Shoemaker spacecraft) is a 1,100-pound robotic craft. It has been built by Johns Hopkins Applied Physics Laboratory (APL) in Howard County, Md. at the cost of $223 million. APL has also been managing the mission for NASA, USA. It was launched in 1996 to investigate Eros 433 asteroid, which is at a distance of 313.6 million km from the earth.

Named after the Greek god of sexual love, Eros is one of the largest and the most accessible space rocks known to travel near the earth. Eros 433 is a 33.6 km long asteroid having an irregular shape. The force of gravity on Eros’ surface averages about one thousandth that on earth. A person who weighs 70 kilogram on the earth would vary from 17 to 40 grams on a tour of Eros.

NEAR had been dancing gingerly around Eros for the last one year. Circling it at distances ranging from 35 to 200 km, NEAR kept on spinning at the rate of one revolution every 5 hours and 17 minutes. Instructions sent between earth and the spacecraft across the 313.6 million km distance, used to take 17.5 minutes one way, at the speed of light. Orbiting around Eros, NEAR took some 1,60,000 images and beamed them back to earth. It has also taken millions of measurements of the asteroid.

NEAR was not designed to land on Eros. But at the end of its expected life and after having satisfied all its objectives, a decision to land it on Eros was taken. The decision has been mildly controversial within the NEAR team. To get NEAR out of its 33.6 km orbit around Eros and to send it towards the asteroid, thrusters were fired around 1531 GMT on Feb 12, 2001. Four subsequent braking burns were allowed to slow the craft to a soft landing. The landing took place almost exactly on schedule shortly after 2000 GMT.

NEAR kept on transmitting signals during its climbdown. It continued its transmission for quite some time after landing on the surface of Eros. It is estimated that it will take years for astronomers to analyse all the data provided by the spacecraft.

The mission to asteroids are worth the effort, because these space rocks harbour specimens of primordial rubble out of which earth and other inner planets formed more than 4.5 billion years ago. In addition to this, some of the larger chunks have helped shape the evolution of earth and its life forms by slamming into it — and one of those still out there just may have to be deflected someday in order to save civilisation. Evidence suggests that the impact of a smaller object wiped out the dinosaurs 65 million years ago and, scientists say there is a slight possibility that Eros will collide with earth — in perhaps 1.5 million years.

The rationale behind sending probes to asteroids becomes more clear when we consider that a typical stony body, around half a km across, may contain 7 billion tonnes of iron, a billion tonnes of nickel and enough cobalt to supply the earth for 3000 years. Other metals e.g. titanium and aluminium, may also be present as high-grade ores.

To date around a hundred asteroids have been discovered. Our current picture of the asteroidal composition is based on spectroscopic studies and the analysis of meteorites. Most asteroids fall into one of two classes: carbonaceous or silicate. The carbonaceous ones make up around 75% of the total asteroid population. Another 15% are silicate and the rest stony.

NEAR’s lead scientist, Andrew Cheng of APL, has said: "NEAR’s wealth of data has already confirmed that Eros is a sample of material largely unchanged since the birth of solar system. The pristine primordial stuff is impossible to study on our own planet or others where geological activity and heat have cooked and pounded it into something else. NEAR has also shown that Eros is a solid whole rather than a ‘rubble pile’ of loosely bound pieces."

The data received from NEAR has answered many questions. But, it has also raised new ones. NEAR’s imagine team leader Joseph Veverka of Cornell University has said: "On the surface of Eros we have noticed strange processes, which haven’t been seen on the moon or anywhere else. There are unexplained landslides of the surface material." The analysis of data received from NEAR is likely to throw more light on the mysteries of Eros.


Sweet healing through honey
Harender Raj Gautam

For treating your wounds, you can skip surgery and swallowing of bulk of antibiotics. In future, when you visit a doctor for treating your wounds he may offer you a poultice of honey. Honey has been used to treat wounds for millennia. In the First World Wound Healing Congress held at Melbourne in September, 2000, researchers deliberated on a significant finding that honey has outperformed antibiotics in treating wounds and even Caesarean sections and burns. They have found that the sweet stuff fights an impressive lineup of microbes, including Escherichia coli, Salmonella and Helicobacter. Moreover, it has been found equally effective against antibiotic-resistant bacteria, including the infamous hospital superbug MRSA. And unlike most other antibiotics, honey actively promotes wound healing. Researchers believe that quality of honey for healing wounds and fighting antibiotic resistant microbes may catapult it from the realms of alternative therapy into mainstream medicine.

Worker bees gather nectar from flowers during spring and summer, and regurgitate it into the mouths of waiting hive-mates. They spit it out into the honeycomb and fan it with their wings until most of the water in the nectar has evaporated. At the same time, their enzyme-rich saliva turns the sucrose into glucose and fructose, which bind to the remaining water leaving a desert in which bacteria cannot survive. While the honey is ripening, though, there is ample opportunity for pathogens to invade. But, protection comes in the form of the bees’ prize enzyme, glucose oxidase, which makes the brew acidic and hostile to most bacteria by converting glucose into gluconic acid.

Sugar concentration and acidity were widely believed to be honey’s only weapons against bacteria, although the plasma that oozes from wounds soon dilutes them away. But it turns out that almost all honeys have a secret weapon that makes it deadly to microbes even in a diluted form: hydrogen peroxide. This chemical was once used to disinfect wounds in hospitals. As it breaks down, hydroxyl radicals are formed that damage bacteria. Hydrogen peroxide had to be applied to wounds at concentrations so high that it damaged healthy tissues. In honey, where hydrogen peroxide is created from glucose, again with the help of the enzyme glucose oxidase, levels of the chemical are 1000 times lower than those traditionally applied to wounds. As a result, there is no tissue damage. In addition, as the hydrogen peroxide breaks down, the enzyme constantly replaces it by catalysing its formation from glucose. The diluting action of fluids produced by a wound actually kick-starts the enzyme, which for unknown reasons is inactive in full-strength honey. Honey can still prevent the growth of bacteria such as MRSA after being diluted to 14 times beyond the point where the sugar content is effective.

Not all honeys possess equal levels of this secret antibacterial weapon. The potency of a honey depends on the bees and the type of flowers they source the nectar. The nectar of some flowers contain high levels of catalase, an enzyme that destroys hydrogen peroxide and thus adversely affecting the healing quality of the honey. Peter Molan-a biochemist, who heads the Honey Research Unit at the University of Waikato, New Zealand, was surprised to discover that even boiling does not destroy the anti-bacterial activity of some honeys. He found that some honeys are so potent that they will stop bacteria growing on agar at a concentration of just 0.4%, while others fail below a strength of 50 per cent. Honey sourced from a New Zealand tea tree called manuka has been found to account for its unusual potency. Molan has found that swallowing half a teaspoon of manuka honey on an empty stomach will put a stop to the Helicobacter that cause most of gastric ulcers. Similarly, Australian honey sourced from jelly bush which, like manuka is sourced from a tea tree, has also shown unusual potency.

Clearly, there is something else too at work other than glucose oxidase and hydrogen peroxide, which is equipping manuka honey from New Zealand and jelly bush honey from Australia with more potency than other honeys. Peter Molan has spent 18 years trying to identify this mystery manuka ingredient in the honey, which he referred as a phytochemical agent and still it has not been isolated in a pure culture. The honey with manuka phytochemical agent has been found to outperform hydrogen peroxide in effectiveness against common bacteria. The phytochemical also works at any pH, even in the acidity of full strength honey, because it lacks an ionic charge.

People probably began using manuka honey on wounds shortly after New Zealand’s newly imported honeybees began churning it out in the 19th century making the mystery phytochemical a relative newcomer on the medicine scene. Elsewhere, honey has been used on wounds since Egyptian times. Honey has also had a huge advantage over conventional antibacterial drugs because it promotes healing. Many other treatments actually damage human cells along with the bacteria. Honey creates an unusually moist environment, which is perfect for tissue growth. Moistness prevents the pain and cell damage that occur when dried-out dressings are changed. Hospital staff have also found that honey cleans away dead tissue painlessly — an appealing alternative to the normally traumatic chemical or surgical removal of necrotic tissue. It works because hydrogen peroxide activates protein-munching enzymes in the patient that dissolves only dead or dying tissue.

Honey’s healing ability has impressed Ken Jones and Rose Cooper from the University of Wales Institute, Cardiff. Jones, an immunologist, informed the congress in Melbourne that weak dilutions of honey activate a type of immune cell called monocytes and monocytes release growth factors that stimulate epithelial cells to regenerate and close the wound. And Keith harding, head of the respected Wound Healing Research Unit at the University of Wales College of Medicine, UK, also reported that laboratory research findings showed such impressive results that honey was tried on some of the patients. He described honey as a very interesting therapy.

Some experts in wound care around the world have adopted honey as a standard dressing for wounds. In other words it is matter of wait and see. Physician are waiting to be convinced and till then honey will hover on the alternative medicine side of the fence. But the spectre of antibiotic resistance makes the bees’ therapy worth persuing.

The writer is from Department of Mycology and Plant Pathology, Dr Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan.



Your obedient servant

It’s a workhorse at your beck and call. Microprocessor intelligence and exceptional dexterity are the hallmarks of this newly introduced robot system with an immense range of automatic functions suitable for complex cleaning and spraying operations, multiple drilling, grinding, welding and carting heavy components with respectable accuracy.

The Ajax Workmaster R-6-140 has six articulated arms designed to handle 140 kilogrammes at a reach of three metres (10 feet), moving it through a horizontal arc of 240 degrees at a linear speed of one metre per second. The robot is programmed using a portable joy-stick control on the main computer console. The selected positions are stored in the memory for use in subsequent programmes.

The Workmaster can be linked to a central computer to extend its programming capacity and automated functions. No specialised computer training is necessary to carry out simple programming of this user-friendly robot.

Sun protection for buildings

To do away with the problem of frequent rolling up and down of curtains, in modern glass buildings, engineers are working to provide windows that automatically produce their own shade.

Researchers at the Fraunhofer Institute for Building Physics IBP, Stuttgart, are developing window-panes which transform to a milky white when temperatures reach a certain level, thus serving as protection from the sun.

Their goal is to find a thermostatic system that could be easily produced and compete with conventional sun-shade installations. They have come up with I-OPAL, a cast resin glass with an integrated polymer layer. This polymer is poured between 2 panes of glass as a thin liquid mass. When exposed to UV rays the polymers turn into a solid mass, making the initially transparent window opaque, Fraunhofer Gesellschaftreports.

Since a combination of temperature and intensity of the UV rays triggers the transformation of the polymer layer, the sun can shine into the building unhindered on sunny winter days.

Once the glass has become opaque, the temperature must drop about 5 to 10 degrees, for the glass to return to its transparent state. These glass planes are also well-suited for sun protection in winter gardens, glass domes, green houses or automobiles. PTI

Chat with your television

Low-fat spreads and cook-in sauces may not seem like the stuff revolutions are made of. But that is exactly how a new advertising campaign from foods giant Unilever is being billed by its creators. The new campaign, for Olivio spread and Colman's sauces, is to be the first interactive campaign to appear on Britain's ITV television channel - and it is being described as the coming-of-age of interactive advertising.

Interactive advertising has already spawned more first-to-market claims than even the most diligent industry observer can remember. We've had the first interactive car advert, the first interactive ad you can play games on and the first interactive ad for a charity. But most have been restricted to niche channels, so for Britain's biggest commercial broadcaster to get in on the act is a milestone.

The campaign is the result of a deal between Unilever and Carlton. Jane Marshall, chief executive of Carlton's interactive operation Carlton Active, helped put the deal together. ``It's about finding ways to add extra value to advertisers,'' she says. Guardian

Robot vacuum cleaner

Researchers have developed a robot vacuum cleaner that zooms along by itself sucking up dust and dirt without any human help.

Developed by Dyson Appliances in the UK, the DCO6 cleaner, which weighs just 9 kg and is controlled by three on board computers, knows where it has been and where it is going. It can stop itself falling downstairs or bumping into anything. All that its owner has to do is to press ‘on’, choose on speed, press ‘go’ and the machine does the rest.

The equipment whirls the dusty air in transparent cylinder inside the machine, flinging anything heavy on to the outer wall. Then, the air pours into a second cylinder where it goes even faster than the speed of sound, sucking in the tiniest particles such as cigarette smoke.

Its 50 sensors take four images a second — these are sent to the computers which chart its position in the room and tell it where to go next. The process is so fast that the cleaner can make 16 decisions a second.

Inventor James Dyson, then a Royal College of Art design graduate in 1979, noticed how the air filter in the factory where he sprayed his Ballbarrows got constantly clogged with powder particles. He designed and built an industrial cyclone tower to clear the dust in the air by centrifugal force at the speed of sound.

Working with the same principle, he and his team developed this most efficient bagless cleaner. PTI

New solar cell developed

In a major breakthrough, material scientists at the Indian Institute of Science in Bangalore have developed a new type of solar cell for converting sunlight into electricity.

The thin film solar cell does not require silicon, is more efficient and cheaper, it is claimed.

More importantly, it is flexible, which means it can be produced like paper rolls and wound around objects of any shape to generate power.

For example when worn like a sari, a woman can become a mobile power plant. Or, it can be wound round the spectacle frame as an invisible power source for the hearing aid for the deaf.

In contrast, today’s silicon photo-voltaic modules atop building or in spacecraft are rigid structures assembled from numerous smaller pieces of silicon.

The new solar cell called copper indium gallium diselenide (CIGS) "will revolutionise the solar photovoltaic industry in three years", S.B. Krupanidhi of the Bangalore institute says.

While research on CIGS cells is currently pursued feverishly in the United States, Germany and Japan, Indian scientists have taken a lead by developing it using "unconventional" technology and replacing the toxic cadmium sulphide "buffer" with zinc oxide.

"Ours is the only CIGS solar cell that is cadmium free", Krupanidhi told PTI later in an interview. This is why safety conscious West is showing interest in the Indian technology. PTI


Science Quiz
J. P. GARG tests your IQ 

1. When this scientist was one day experimenting with a mixture of rubber and sulphur, some of the mixture accidentally fell on a hot stove. The scientist was pleasantly surprised to find that this portion turned into dry and flexible rubber. Who was the scientist? Which process had he discovered?

2. Two international organisations, Celera Genomics Group and Human Genome Project, have recently released the map of the human genome comprising 3.1 billion chemical letters of DNA deciphered and arranged in order across all 23 chromosomes.What popular name has been given to this map?

3. Continuing on the subject, earlier it was predicted that human biology is controlled by the actions of 100,000 or even more genes. But scientists have been surprised to find that this number is actually much less. Can you tell this number?

4. It is now believed that there is more matter in the universe than is visible to us as stars, galaxies, nebulae, etc. what is this matter called which has not been detected so far but the presence of which is indicated by its gravitational effects on visible bodies?

5. In which form is energy used maximum in the world? What are the two main reasons for using energy in this form?

6. Based on the study of these birds, the renowned English naturalist Charles Darwin propounded his theory of evolution by natural selection and wrote the world famous book “The Orgin of Species”. Which are these most famous birds in science?

7. It is found that proton-proton, proton-neutron and neutron-neutron interactions within the nucleus are identical. What is this property of nuclear forces called?

8. Each radioactive series finally leads to a stable non-radioactive element as the end product. Which element?

9. Recent studies have shown that a yellow coloured spice used in almost every Indian home, besides having other curative properties, can inhibit the production of an enzyme found in abnormally high levels in certain cancers, especially bowel cancer. Thus this spice can prevent and treat such cancers. Which is this spice?

10. Where was the Fourth Punjab Science Congress held recently? What was the theme of this Congress?

1. Charles Goodyear; vulcanization of rubber 2. “Book of life” or “book of human heredity” 3. About 30,000 4. Dark matter 5. Electricity; it can be easily transported and converted into other forms of energy 6. Galapagos finches or “Darwin” finches 7. Charge independence of nuclear forces 8. Lead 9. Turmeric 10. At Punjab Agricultural University, Ludhiana; “Science and Technology in Economic Development of Punjab, Vision-2020”.