Category Science

Nature’s theatrics

The universe has always been an enigma. There is so much to learn and experience from nature. Sometimes, nature delights us with some breathtaking spectacles of hers. We take you through some of these wow moments.

MOONBOW

You have seen a rainbow. Have you seen a moonbow? This is a light show like no other. The moonbow is a very rare optical phenomenon. It occurs when the light from the moon gets reflected and refracted through water droplets in the air at a certain angle. Much like how a rainbow forms. But moonbows are faint as the amount of light from the moon, which is reflected sunlight, is less. It is said that the first mention of moonbows was by Aristotle back in 350BC. As there is more light during the full moon phase, the likelihood of seeing a moonbow is more at this time.

Every year, during spring and autumn, the Denmark skies become a canvas of sorts as starling birds whiz through the skies in millions. The birds flock together in large numbers and even the sun gets partially blocked by them. This has earned the phenomenon the name Sort Sol meaning Black Sun in Danish. This spectacle across the skies occurs because of the migrating starlings as they head to their breeding grounds. This can be seen only in Denmark.

SKY MIRROR – BOLIVIA

This is akin to a mirror on the floor. The Salar de Uyuni in Bolivia is the world’s largest salt flat. When the lake water flows onto the flat, the water reflects the sky above, just like a mirror. These salt flats are vast and endless and the waters create a reflection that makes for an extremely enigmatic sight.

NORTHERN LIGHTS ICELAND

Sometime between September and April, the skies in Iceland turn theatrical as they put on a spellbinding show of colours. Awe-inspiring patterns form in the sky in hues of green, red and blue. This natural phenomenon is called the Aurora Borealis or the northern lights. They form when the charged particles of the sun interact with atmospheric atoms.

BIOLUMINESCENT SHORES – MALDIVES

Picture this. A beach glowing neon blue at night. If you were to go to the Vaadhoo Island of the Maldives between the months of June and December, you will get to witness a glorious abstract art painted by nature herself on the sea. The waters appear soaked in a blue hue because of the phenomenon called bioluminescence as light gets emitted by a microorganism called phytoplankton present in the sea.

LIQUID RAINBOW-COLOMBIA

Imagine a river full of colours, more like a watercolour palette. The Caño Cristales river in La Macarena turns into a vibrant colourscape between the months of July and October. The river gets bathed in colours of red, yellow, green and blue as a result of the reproduction of the aquatic plant Macarenia clavigera, a species of the river weed family, during that time. The 62.1-mile-long river runs through the Serranía de la Macarena national park in Colombia.

Picture Credit : Google 

Nature’s masterstroke

Autumn showcases nature in all its splendour. How do the colours of leaves change during the season? Why do leaves fall? How do animals react to the change in season? Come, let’s find out

Autumn is a transitional period between summer and winter. It is one of the four seasons in the temperate zones. According to the Hindu calendar. Sharad ritu is synonymous with autumn. But autumn

is not very distinct in India, except in some parts of the Himalayas, especially the Kashmir Valley. In the northern hemisphere, autumn begins with the September equinox which occurs on September 22 or 23 each year. This is when the sun crosses the celestial equator and moves southward. During the equinox, the day and night are of nearly equal duration.

Fall colours

French littérateur Albert Camus has aptly described the season- “Autumn is a second spring when every leaf is a flower!” Indeed as the days grow shorter with a perceptible nip in the air, Mother Nature too begins to discard her universal green and sets the countryside on fire with gorgeous red, orange, yellow or brown.

The leaves of many deciduous plants change colour. A leaf contains three pigments-chlorophyll (green), carotenoid (yellow, orange and brown) and anthocyanins (red). Of these, chlorophyll and carotenoid are present in leaf cells during the growth period. But the chlorophyll covers the carotenoid and hence we see only the green colour. Anthocyanins are produced only in autumn under certain conditions in some trees.

During winter, there is not much sunlight for photosynthesis to take place. Trees begin to temporarily shut down their food factory. The green chlorophyll begins to disappear from the leaves and the vivid colours of the carotenoid come alive.

The eastern parts of the U.S. and Canada, Scandinavia, western parts of Europe, China, Korea and Japan are famous for the spectacular fall foliage. Thousands of tourists flock to these places to soak in the flamboyance of nature before everything gets covered by a white blanket of snow!

Why do leaves fall?

The root, stem and branches of trees are able to withstand the harsh winter but not so the tender leaves- they freeze in winter. Therefore, the leaves are shed to ensure the tree’s survival. With the onset of autumn, a layer of cells called the ‘separation layer forms at the base of each leaf. When this layer is complete, the leaf is separated and it falls.

Trivia

*As the mercury begins to drop in the late fall season, people look forward to the ‘Indian Summer’. It is an unusually warm, dry spell which follows frosty weather.

*Autumn is associated with a sense of melancholy, especially by poets. “To Autumn” by well-known English poet John Keats is an ode to the season.

*Chinar, the signature tree of Kashmir, paints the entire valley in gold and crimson red during autumn.

* In the West, the new academic year in schools and colleges coincides with the fall season.

ANIMAL KINGDOM

Come autumn and animals know instinctively that the fun and frolic of summer is over and it’s time for hard work! The falling temperature and reducing daylight trigger hormonal changes in animals. Many birds, animals and even insects begin their long, arduous journey to warmer places to escape the harsh weather ahead

Those who wish to stay put find their own ways to brave the winter. Furry animals grow a thicker coat, while birds grow extra feathers. As autumn gets underway, squirrels, beavers, rodents and even ants get busy gathering food for a snowy day. For those who plan to sleep through winter, autumn is feasting time! Bears chipmunks, hedgehogs, etc. consume excess food and store it as body fat to sustain them during hibernation.

Picture Credit : Google 

The river as a dumpyard

The Mekong is one of the longest rivers in the world, cutting across several Asian regions from Tibet and China to Thailand and Cambodia. But spanning a large area means the threats it faces are just as huge. What are they? Come, let’s find out.

Waste generated in any region is disposed of in many ways, including being dumped at landfills. (Only a minuscule fragment of waste is recycled globally.) Some countries export their waste. Several Asian countries have been taking in plastic waste from such countries, without really being equipped to handle waste disposal safely. In addition, these Asian countries have their own waste to deal with. The waste in landfills reach rivers and oceans through winds, rains, and drains. One such river is the Mekong. Painfully, three “of the worst six plastic polluting countries China, – Thailand, and Vietnam – have a presence in Mekong”, meaning the quantum of waste this river takes in is huge and increasing. The pandemic, with its masks, plastic sanitiser containers, take-away plastic boxes, etc., has exacerbated the situation. And, this is of grave concern.

The Mekong is a treasure trove of biodiversity – several species of plants, birds, reptiles, and fishes call the river and its surrounding regions home. But in the current scenario, rubbish is finding its way into the water, endangering wildlife. Animals and birds are in danger of being affected by plastic debris through entanglement or ingestion. There have been instances of dead whales “turning up in Thailand and Indonesia with many kilograms of plastics in their stomachs”. It is not just wildlife that’s affected. When humans consume creatures such as fish, we end up consuming plastic, which has the potential to cause serious health problems such as cancer. Since rivers drain into larger waterbodies such as seas (the Mekong mixes with the South China Sea) and oceans, the pollution they carry is transferred too.

An increase in the pollution of waterbodies is an indication of increasing pollution on land. And a grim reminder that unless we change our lifestyles to make this planet greener, we are likely to face the negative consequences of our own actions.

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What are dwarf galaxies?

As their name suggests, dwarf galaxies are smaller galaxies. In contrast to a normal galaxy that comprises hundreds of billions of stars, a dwarf galaxy would contain just about a few billion stars. These dwarf galaxies orbit larger galaxies after their formation.

Formation of dwarf galaxies

The dwarf galaxies are created when two galaxies collide, fromed from the material and dark matter coming out of the galaxies that collided.

Following these collisions, while a significant portion of the gas, dust and stars emitted gets reincorporated into the galaxy created after the collision, some can lead to the formation of dwarf galaxies which then orbit around the galaxy. They are also formed by the gravitational forces existing during the creation of these larger galaxies.

Why are dwarf galaxies crucial

Scientists consider the dwarf galaxies critical as they could help gain insight into the early stages of the formation of galaxies and stars. According to scientists, our galaxy has about 14 satellite dwarf galaxies orbiting it.

Studies are being carried out on these dwarf galaxies as it would give us clues regarding the evolution of the galaxies. By studying the motion of the stars in these galaxies, we would also get to know more about dark matter and how it is distributed in the galaxies.

It is difficult to spot dwarf galaxies as they are less bright when compared to larger galaxies. A large number of them can be spotted in galaxy clusters or as a companion to larger galaxies.

Shapes of dwarf galaxies

The dwarf galaxies take several shapes. The dwarf elliptical galaxies are quite similar to normal elliptical galaxies.

Then there are dwarf spheroidal galaxies which are more spherical in shape and smaller when compared to the former.

Then we have the irregular dwarf galaxies. They do not have a distinct structure and are rich in gas.

One of the closest dwarf galaxies to the Milky Way is the Sagittarius Dwarf Spheroidal Galaxy.

Picture Credit : Google 

Is a missing moon responsible for Saturn’s rings and tilt?

Now known to host at least 83 moons, researchers propose that Saturn at one point must have had at least one more satellite, which they call Chrysalis

While all four gas giants – Jupiter, Saturn, Uranus, and Neptune – have rings, Saturn is the most popular ringed-planet. Swirling around Saturn’s equator, these rings indicate clearly that the planet is spinning at a tilt relative to the plane in which it orbits the sun.

For a long time, astronomers have suspected that this tilt is the result of Saturn’s interactions with neighbouring Neptune. A new modelling study by astronomers at Massachusetts Institute of Technology (MIT). however, suggests that while the two planets may have been in sync before, Saturn has since escaped Neptune’s pull.

Call it Chrysalis

In a study appearing in Science in September, the MIT team

posits that a missing moon might be responsible for this planetary realignment. Now known to host at least 83 moons, Saturn at one point must have had at least one more satellite that the researchers call Chrysalis.

The team estimates that after orbiting Saturn for several billion years, Chrysalis became unstable about 160 million years ago, coming too close to Saturn in the process. As the proposed satellite was long dormant before suddenly becoming active – just like a butterfly’s chrysalis – the researchers gave it the name Chrysalis.

The resulting encounter pulled the satellite apart and the loss of the moon was enough for Saturn to escape

Neptune’s grasp and leave it with its current tilt. Additionally, the researchers suggest that while most of Chrysalis’ shattered body may have impacted Saturn, a fraction of its fragments could have remained suspended in orbit. These could then have broken into small icy chunks to form the planet’s standout rings.

Explains two mysteries

The missing moon hypothesis, the researchers believe, could thus explain two mysteries pertaining to Saturn’s system. While one of these is Saturn’s present-day tilt, the other one is the age of its rings.

The rings are estimated to be about 100 million years old. very much younger than the planet itself. If the rings were indeed formed from fragments of Chrysalis, then the story fits perfectly.

Cassini’s inputs

The team of researchers arrived at this hypothesis by modelling the interior of Saturn. They identified a distribution of mass that matched the gravitational field that was observed by the Cassini spacecraft in its final phases. What they found indicated that Saturn is no longer in sync with Neptune, paving the way for researching various hypotheses, before arriving at their final result. The lead author of the study says that it is “a pretty good story, but like any other result, it will have to be examined by others”.

Picture Credit : Google 

How is climate change affecting penguin in Antarctica?

The warming climate is having an impact on Antarctica and its large penguin population. Here’s a firsthand account of a trip through the frozen continent by an agriculture and environment scientist

No one owns Antarctica, but the penguins call it home. A frozen landmass that is over four times bigger than India, it has become a bellwether of the climate crisis.

Last year, a large chunk of ice-1.270 sq. km wide-split from the continental shelf causing concern among scientists. Was it due to climate change? Scientists are not sure. But what they know is that the rate of ice loss in Antarctica has tripled since 2012 compared to two decades earlier. Large chunks are splitting regularly from ice shelves, often requiring maps to be redrawn. The warming climate is having an impact on the 6-km-deep ice sheets and the resident penguin population.

Home of penguins

An estimated 12 million penguins live in Antarctica, though it is not their only habitat. Of the 18 species, only five live in Antarctica, including the renowned emperor penguins who march across the frozen tundra in a mating ritual that was featured in the documentary. “March of the Penguins” (Unfortunately, a new report forecasts that the entire population of emperor penguins may disappear by the year 21001)

Inspired in part by the movie and a desire to see the impact of climate change, I flew with two friends to Antarctica a few years ago. It was quite an adventure.

A plane took us from Punta Arenas, Chile, to the Chilean air base on King George Island. As it landed, a group of curious gentoo penguins came out to greet us. They were probably wondering who we were and why we were invading their space! We saw more of their cousins and their colonies as well as elephant seals and leopard seals when we explored the land and the sea over the next few days.

Cause for concern

About 90 per cent of the world’s ice and 70 per cent of fresh water is in Antarctica. Some have calculated that if all of Antarctica’s ice melted, sea levels would rise 60 to 70 m. drowning all coastal cities. Should we be concerned? Most certainly, as we would want to bequeath a better planet to future generations.

Antarctica is regarded by scientists as the perfect place to do research on flora and fauna, climate and a variety of issues-so there are 70 research stations involving 29 countries. Though there is no native human population, visiting researchers hope to find new organisms or data that could reveal the Earth’s climate history and signs of a changing environment.

 

Living and doing research in a place, where temperatures can dip to minus 90 degrees Celsius and dark winters last six months, can be a challenge in the best of times. But it became a bigger challenge during the pandemic. In December 2020, the Chilean research station reported 36 COVID cases and the affected persons had to be evacuated to their home country.

New research

In 1985, British scientists discovered a hole in the ozone layer above Antarctica, which revealed the damage done to the Earth’s atmosphere by manmade chemicals. In 2012, U.S. researchers discovered that Antarctica was melting twice as fast as previously thought. They also found that a warming ocean west of Antarctica would enable the king crab to move from the deep sea to shallower waters, making it a big predator and disrupting the ecosystem.

In 2017, India’s polar biologists stumbled upon a species of moss they named Bryumbharatiensis. How had moss survived in this barren landscape? Dr Felix Bast, a member of the Indian research team, observed that the moss is nourished by penguin poop, which contains nitrogen and does not decompose in a frigid climate.

Impact of climate change

Sadly, Antarctica will not remain a winter wonderland for long on account of climate change. A group of scientists led by Stephen Rintoul have presented two stark images of Antarctica by 2070. In Vision 1, assuming global air temperatures rise 2.9 degrees Celsius, they predict sea levels will rise 27 cm, ice sheets will be reduced by 23 per cent and damage to the ecosystem will be most severe. In Vision 2, assuming a 0.9 degrees Celsius temperature rise, sea levels will rise only 6 cm, ice shelf loss will be 8 per cent, and damage to the ecosystem will be less severe. The outcomes will be determined by the climate actions we take in this decade. If global warming remains unchecked, it is quite possible that Antarctica will “be the world’s only habitable continent by the end of this century,” warns Sir David King, former Chief Scientist to the British government. Will humanity rise to the climate challenge?

Picture Credit : Google