Category Science

Which is the innermost planet in the solar system?

 “Mercury stays close to the Sun like a child clinging to its mother’s apron strings.” – Huber J Bernhard, American astronomer

The planet Mercury was known from ancient times. Because it was so elusive ad swift in its revolution around the Sun, it was named after the fleet-footed Greek messenger of the gods, Herms or the Roman Mercurius. Mercury was known for his speed and agility, wore a winged cap and shoes and bore a staff entwined with two snakes (called a ‘caudaceus’). He was also the god of thieves and trade. He is believed to have crafted the musical instrument called a lyre from the shell of a tortoise. It had nine cords representing the nine Muses. Mercury gifted the lyre to Apollo, the sun god and received the caudaceus from him in exchange.

Since it is the innermost planet in the solar system, Mercury can rarely be seen due to the Sun’s glare. Even the great astronomer, Copernicus, is rumoured not to have seen it. Its gravity is less than half of earth’s, so it barely has an atmosphere, which is thought to be made up of helium. With no air to temper the Sun’s rays, Mercury’s temperature fluctuates widely. The side facing the sun roasts in 482 degrees C, while the side facing away is a freezing-184 degrees C. It goes round the Sun at breakfast speed, the fastest revolution in the solar system. Like the other Earth-like planets (Venus and Mars), it is made up mostly of rock and metal. Its surface resembles the Moon with hundreds of craters Scientists believe that the planet is slowly buckling inwards and shrinking in size because its core, largely made of iron, is freezing. The photographs taken by Manner 10 show great gashes across its surface, one measuring nearly 2 km in length. They resemble the fault line across Earth’s crust (along which earthquakes occur).

 

Picture Credit : Google

Who are wombats?

Odd-looking, but cuddly

The pudgy and furry wombat is one of the oddest-looking animals on Earth – rather like a pig, bear and koala all rolled into one.

There are three species of wombat: the common wombat (Vombatus ursinus), the northern hairy-nosed wombat (Laisorhinus krefftii), and the Southern hairy nosed wombat (Lasiorhinus latifrons). You will be able to see all three in Australia and Tasmania, usually in forested and mountainous area.

Marsupial

Wombats are marsupials, related to koalas and kangaroos. They usually live up to 15 years in the wild, but can live past 20 and even 30 years in captivity. Rotund, with stubby tails, short ears and tiny eyes, wombats grow to around one metre in length and weigh anything between 20 and 40 kg. their fur is either sandy brown or grayish-black and this helps them blend with the landscape – a way of safeguarding themselves from predators.

Big eaters

These animals are nocturnal and emerge from their burrows to feed at night. Being herbivores, they feed on grasses, herbs, bark, and roots. They spend a lot of time, eating. They have sharp large incisors like rodents which help them gnaw at thick vegetation. Their teeth never stop growing. But they are slow to digest their meal – it takes around 8-14 days for them to fully digest their food. But this helps them adapt to Australia’s arid conditions. Since they derive most of the moisture they require from plants, they don’t need to drink much water either. And interestingly, they are the only creatures in the world to excrete poop that is cube-shaped!

Burrowing away!

They are amazing burrowers and dig lengthy burrow systems with their razor-sharp teeth and claws. Common wombats are shy and solitary and inhabit their own burrows, while the other two species may be more social and live together in large groups in their warren.

Quick sprinters

Wombats may look plump and slow, in fact, their walk is more of a waddle. Despite their podgy bodies and stubby feet, they can run really fast – even up to 40 km/h.

Just communicate

They communicate with one another in various ways – vocalizations, aggressive displays, and markings on logs and branches made by rubbing against them repeatedly. Wombats tend to be more vocal during mating season. When angered, they can make hissing sounds.

Jellybean or joey?

Female wombats give birth to a single young one known as a joey in the spring, after a gestation period of 20-21 days. When the joey is born, it is the size of a jellybean and not completely developed. The joey climbs into it mother’s pouch right after birth to finish developing and stays there for about five to six months. Wombats are weaned after 15 months.

Once pests, now protected

In 1906, the Australian government declared wombats pests and encouraged people to kill them. From 1925 to 1965, some 63,000 wombats skins were redeemed for cash. Fortunately, this practice has stopped. All species of wombats are protected in every state except for Victoria.

Powerful posterior

Startled wombats can charge humans and bowl them over, with the risk of broken bones from the fall, besides wounds from bites and claws. When running away from predators like Tasmanian devils and dingos, wombats rely on their thick rump skin to protect them. Their rear-ends are mostly made up of cartilage, which makes them more resistant to bites and scratches. At the end of a chase, wombats will dive into their burrows and block the entrance with their posterior. They’re also capable of using their powerful backs to crush intruders against the roofs of their burrows.

Wombat facts

  • A group of wombats is known as wisdom, a mob, or a colony.
  • Believe it or not, wombats can jump! Some have been known to jump over metre-high fences.
  • The giant wombat, an ancestor of modern-day wombats, lived during the Ice Age and was the size of a rhinoceros.
  • Since 2005, Wombat Day is observed in Australia on October 22.
  • Wombats have featured in Australian postage stamps and coins and ‘Fatso’, the wombat, was the unofficial mascot of the Sydney 2000 Summer Games.

 

Picture Credit : Google

Why do stars seem to twinkle?

Stars do not really twinkle, they just appear to twinkle when seen from Earth, because of out atmosphere. When light from the faraway stars enters the Earth’s atmosphere, its path is affected by air movement, temperature and the density of various layers in the atmosphere. This causes the light from the stars to refract multiple times before reaching us, making the stars look as if they were blinking.

The telescopes we send into space take better pictures of stars than telescopes on Earth because the telescopes in space do not have to take pictures through our disturbing atmosphere. For the telescopes on the ground, scientists use lasers and mirrors to adjust to the star’s twinkling, which creates a clearer picture of distant stars.

Stars appear to twinkle to us on Earth because our planet’s atmosphere contains wind, temperature differences, and density variation. As the light from a distant star passes through our chaotic atmosphere, the light spreads out and becomes bend. The bending and spreading of starlight as it reaches our eyes causes us to see twinkling stars.

 

Picture Credit : Google

What is the current issue with sea urchins along the California coast?

California has been in the news for all the wrong reasons. On the one side, this U.S. State has been fighting a series of wildfires that have destroyed acres of forests and displaced thousands of people. On the other, it’s facing threat from the explosion of a marine species called the purple sea urchin. These urchins have chomped off 90% of the bull kelps along the coastline of California and neighbouring State Oregon, putting the entire coastal ecosystem out of whack.

Kelps are a type of a large brown seaweed that grow in shallow, nutrient-rich saltwater, near coastal fronts around the world. They offer shelter to a host of sea creatures. The coastal water of northern California was once home to a dense coverage of kelps. But today, they have been replaced by purple sea urchins. The vast stretch of the seafloor is barren and is dotted with nothing but tens of millions of these spiny orbs.

Sea urchins are typically spiny, round creatures, inhabiting all oceans. They belong to the phylum Echinodermata – the same group or sea stars, sand dollars, sea lilies and sea cucumbers.

The purple sea urchin – Steongylocentrtus purpuratus – is voracious, kelp-eating species. They are particularly fond of bull kelps. They are native to California’s coast, and have traditionally been found in smaller numbers. But now, from California, the population of the sea urchins has spread to Oregon reef, where their count has been found to be 350 million – more than a 10,000 % increase since 2014. These millions and millions of sea urchins are eating away not just kelps but also anemones, the sponges, flesh red algae and even sand, say scientists.

Cascade of events

Sea water wasting

The trouble began in 2013, when a mysterious disease began to spread among starfish. Scientists are not sure what caused the diseases in sea stars. It wiped out tens of millions of the species. This included sunflower sea water, which is the only real predator of the purple urchin. With no predators to keep the population in check, the hitherto harmless purple sea urchins began to grow and multiply, eating everything in sight. Destruction of kelps, their primary source of food, left other creatures depended on it to starve and die. Meanwhile, purple sea urchins’ population grew 60-fold between 2014 and 2015.

Double whammy for kelps

The kelps had already been struggling because of warmer-than-usual waters in the Pacific Ocean. Warm waters are nutrient poor, and as a result, the kelp cannot grow high enough to reach the surface of the water for photosynthesis. The 2014 record-breaking heatwave and subsequent El Nino condition in 2015 fuelled their decline further.

Ecosystem collapses

As the kelps population declined, 96% of red abalone, a type of sea snail that feeds on kelp, died from starvation, by 2017. According to a study, red sea urchins, a meatier relative of purple urchins, are also declining due t lack of food kelps.

Fisheries affected

The devastation is also economic. Until recently, red abalone and red sea urchins supported a thriving commercial fishery in both California and Oregon. But the mass moralities of red abalone led to its closure in 2018. The commercial harvest of red sea urchins in California and Oregon also has taken an enormous hit.

Can kelps rebound?

  • Bull kelp is one of the fastest-growing algae on Earth and if the cooler water temperatures return, the seaweed may be able to bounce back. But the excessive numbers of purple sea urchins will still pose a problem.
  • The only way to restore the kelp is to remove the purple sea urchins. But to remove the ones in Oregon alone, it would take 15 to 20 years, by scientists. Without the kelps, purple sea urchins by themselves may decline. But again it could be a long wait.
  • Conservationists suggest urchin farming as a solution to the problem. It involves physically removing large numbers of purple sea urchins from the seafloor to be flattened up in controlled environments for human consumption.
  • However, even if the kelps rebound, it may take decades for the entire ecosystem to bounce back to its past glory.

 

Picture Credit : Google

How do animals communicate?

Strange are the ways of the animal world. We think animals are “dumb”, but they have surprising ways of talking to each other. How do animals say “Hey, want to play chase-the-tail?” or “You think we can eat this?” Animal languages don’t have names and we can’t tell what they are saying, but we do know that dolphins whistle, hyenas laugh, wolves howl, lions roar, elephants trumpet, birds whistle, tweet and chirp, frogs croak – to send messages across. And making sounds isn’t the only way they can say “I love you!” They use a dictionary of non-verbal means!

Touch

Chimpanzees greet each other by holding hands, monkeys groom each other by picking off dead skin. Pets and domestic animals lick to show affection. But elephants would be the best examples for communicating through touch. They deliberately touch one another with their trunk, tusks, feet, tail and sometimes through their entire body – to explore, play, protect, fight. Have you seen elephants greeting others with a raised trunk? Use their ears to rub a mate affectionately? Push a calf to join the queue? So it is a crime to keep elephants alone!

Colour

The male koel has a shiny coat, the peacock is a vision when it spreads its wings full of “eyes”. Leaf insects sit on green leaves, stick insects look like dry sticks. Brightly-coloured butterflies are either poisonous butterflies.

Big cats merge beautifully with the tall, dry grass. The fennec fox that lives in deserts has a coat in sand-colour. Using the colour of the background to hide is called “concealing colouration.”

Doesn’t the chameleon change colours repeatedly to match its changing habitat?

Chemical marking

The dog sniffs and pees from time to time on the sidewalk to mark its territory. This “chemical communication” is mostly through pheromones (substance released to convey a message) and through body fluids such as urine and venom. Chemical signals can be air-or-waterbone. You see, snakes can “taste” enemies from a distance by using their forked tongues and the roof of their mouth to collect pheromones. Most big cats mark their territory by urinating. Dogs sniff each other’s hindquarters for information. Cats rub their heads against a person or object to release pheromones to say, “You’re mine!”

Auditory

Animal cries signifying danger or distress are now understood well by humans. Sound travels long distances and becomes an effective medium of communication. Almost all animals call – the cuckoo sings to find its mate, doves coo, frogs croak, male crickets chirp to attract and to warn. Female cicadas respond by snapping their wings. Mammals in the oceans, like whales and dolphins, “speak” at ultrasonic frequencies to communicate over long distances, since visibility is poor in water.

 

Picture Credit : Google

What is crowdsourcing?

When the online community (or crowd) is asked for services, ideas or content, it is called crowdsourcing. When a project is too vast and time-consuming for an individual or a small group of individuals to accomplish, they put the proposal online and invite netizens to contribute their ideas, insights and experience to complete it. The task is then divided among those who volunteer to work on the assignment either online or offline. Some projects pay the participants.

Crowdsourcing is essentially social networking used to gather scientific data, to locate missing persons, to raise funds for charity and to finance promising innovations and start-ups (also called crowdfunding).

The American Human Genome Project that mapped the sequences of all the 3 billion base pairs of human DNA was one of the major scientific projects to use crowdsourcing. The manmoth project took the help of researchers across Asia and Europe and managed to finish its task within ten years!

The term was first used in 2006 in an article by Jeff Howe for Wired magazine.

 

Picture Credit : Google