Category Science

How are cyclones named?

Hurricanes and tropical cyclones in the Atlantic Ocean have been named since 1953 when Miami’s National Hurricane Centre started the practice. This was then maintained and updated by the World Meteorological Organisation (WMO), a Geneva-based agency of the United Nations. The name is suggested by member nations by turn.

The countries of South Asia in West Asia chose not to name their cyclones until 2004 when the World Meteorological Organisation brought about agreement between eight countries in the region, namely, India, Pakistan, Bangladesh, Maldives, Myanmar, Oman, Sri Lanka and Thailand. This group came up with a list of 64 names, eight from each country, for cyclones – Hikka and upcoming ones.

As of September 2019, 58 of the 64 names have already been used! The cyclone that recently formed was called Hikka (Maldives), and this will be followed by Kyarr (Myanmar), Maha (Oman), Bulbul (Pakistan), Pawan (Siri Lanka), and Amphan (Thailand).

 

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What is lunar litter?

Since the 1950s, when the space race began, a number of countries, most notably the US and the former Soviet union, as also India, have been sending manned and unmanned missions to the moon and other planets. When the missions end, the probes are inevitably crash-landed on the heavenly body they were investigating.

This means that not only has man filled his home planet with trash , he has also left tonnes of debris strewn on planets and their satellites across the solar system. The moon in particular has nearly 180,000 kilos of man-made material lying on it.

Litter on the lunar surface includes wreckage of spacecraft–more than 70 vehicles in all. Other objects include geological tools, shovels , rakes, plaques , flags, golf balls, dozens of pairs of boots, 96 packs of faeces, urine and vomit, empty food packets, TV cameras, magazines, backpacks, medals, pens, a silicon disc with messages from 73 world leaders, an Eagle feather and even a golden olive branch!

Astronauts from the Apollo missions alone left over 50 tonnes of litter.

Is there a law to prevent countries from littering space? The 1967 Outer space Treaty does require explorers to ‘avoid harmful contamination of the moon and other celestial objects’. But since it bans territorial claims in space, there is no central authority to enforce law against littering or anything else.

NASA keeps a list of all human-introduced garbage on the moon but it also tries to protect remains of the Apollo missions citing their ‘historical and scientific value’!

 

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Why did the Babylonians show a special interest in studying about the Moon?

          The temple astronomers of Babylon had observed the skies for centuries and had recorded their observations in astronomical diaries, and other catalogues. Their predictions are almost accurate to this day.

          In fact, the Assyrians and Babylonians regarded lunar eclipses as evil omens. They believed that eclipses were directed against their kings. This was one reason why they studied more about the Moon. They studied the length of the synodic month, the period between two full moons. Their observations were almost error free. Using these data on the synodic month, the Babylonian astronomers were able to predict lunar eclipses and solar eclipses later.

          They also recorded the 18-year Saros cycle of lunar eclipses. A Saros cycle is the period of 223 synodic months-18 years and 11.3 days- after which lunar and solar eclipses repeat themselves. The predictability of the lunar eclipse made it possible for the Babylonians to appoint substitute kings who would bear the burden of the wrath of the gods.

Picture Credit : Google

 
 
 

 

Will the Black-footed ferret survive the onslaught of urbanisation?

The black-footed ferret is a long, slender animal. Nature has made these mammals that way to enable them to easily slip through prairie dog burrows. You may wonder why they haunt these burrows – it’s because their main diet is the prairie dog! Also, they make the burrows their cosy home. They weigh between 1.5 and 2.5 pounds and can grow up to 24 inches long. A strip of dark fur across their eyes gives them the appearance of wearing a mask – rather like bandits!

This member of the weasel family once roamed the prairies from southern Canada to Texas but is now one of the most endangered mammals in North America. In the early 1900s, the United States was perhaps home to over 5 million ferrets. Early in the 20th Century, when agricultural development took place in the U.S., rodent poisons practically wiped out prairie dog populations and in turn the ferrets. Thirteen years after they were listed as endangered in 1967, the last captive ferret died, and the animals were thought to be extinct in North America. Then in 1981 a small population was discovered in a Wyoming prairie dog colony. Between 1991 and 1999, some of these ferrets were released in Wyoming, Montana, South Dakota, Arizona and along the Utah/Colorado border. And that’s how they were brought back from the brink of extinction. Biologists estimate that are now well over a 1000 black-footed ferrets living in the wild. The average life span of a ferret in the wild is 1-3 years, and 4-6 years for ferrets in captivity.

There are only three ferret species on Earth: the European polecat, the Siberian polecat, and the black-footed ferret. The black-footed ferret (Mustela nigripes) is the only ferret species native to North America. Female ferrets are called “jills”, males are called “hobs” and the young ones are called “kits”. The slender animal has buff or tan fur, with black feet, tail tip, nose and face mask. It has triangular ears, hardly any whiskers, a short muzzle, and sharp claws.

While their main diet is the prairie dog, in regions where prairie dogs hibernate in winter, ferrets feed on mice, voles, ground squirrels, rabbits, and birds. Black-footed ferrets get water by consuming their prey. Ferrets are preyed upon by eagles, owls, hawks, rattlesnakes, coyotes, badgers, and bobcats.

Except when mating or raising their offspring, black-footed ferrets are solitary, nocturnal hunters. They use prairie dog burrows to sleep, catch their food, and raise their young. They are vocal animals their sounds ranging from hisses, whimpers to loud chattering. Like domestic ferrets, they perform the “weasel war dance”, consisting of a series of hops, often accompanied by a clucking sound (dooking), arched back, and frizzed tail. In the wild, the ferrets may dance to distract prey as well as to show they are enjoying life.

 

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What are the challenges in a spacewalk?

Movement: Spacewalk is a challenging task for multiple reasons. Imagine fixing a bolt in a machine while remaining in water. That’s why astronauts practise spacewalks underwater in a large swimming pool near NASA’s Johnson Space Center in Houston, Texas. The astronauts also practise by using virtual reality simulation). As moving in space is difficult, astronauts have their feet attached to a plate to allow them to carry out repair work or experiment with less difficulty.

Temperature: Despite the cooling system in the suit, it could be very hot or cold. Remember, the astronauts do not have the luxury of Earth’s atmosphere to protect themselves from direct sunlight. The temperature can soar in direct sunlight near the space station’s reflective surfaces, or plummet when the sun goes out of sight.

Space debris: The astronauts also risk being hit by space debris or micrometeoroid.

Decompression sickness or bends: Once in their suit, astronauts breathe only oxygen for several hours until all the nitrogen is out of their body. (You must be aware that when we inhale, we don’t take in just oxygen, but also nitrogen which is exhaled as it is by the body. Only oxygen in the air is taken into the blood stream, while other gases along with the CO2 are exhaled). During a spacewalk, nitrogen can cause gas bubbles to form in the body, which can lead to pain in joints such as shoulders, wrists and knees. This condition is called the bends or decomposers sickness.

 

Picture Credit : Google

 

How is a spacewalk performed?

Astronauts undergo many hours of training to familiarize themselves with the exact route they will have to take once out of the space station.

A spacewalk may be either tethered- the astronaut is connected to the spacecraft- or untethered. (Untethered spacewalks were performed only on three missions in 1984 using the Manned Manoeuvring Unit (MMU).)

Astronauts use tethers to remain attached to the space station. They also use tethers to keep tools from floating away. What if they get untethered by accident? NASA spacesuits have mini-jet packs which enable the spacewalker to float back into the station.

 

Picture Credit : Google