Category Science

What are the different ways of taking food by animals?

Animals Eat

All plants and all animals need food. Most plants make their own food from light, water, and substances in the ground and air. But animals cannot make their own food. They must eat plants or other animals to live. Different kinds of animals eat in different kinds of ways. A chameleon flips out its sticky tongue and catches insects. A lammergeyer, a type of vulture, uses its sharp claws and hooked beak to tear its food.

A butterfly has a part of its mouth like a built-in straw. It’s called a proboscis. The butterfly keeps its proboscis rolled up until it gets hungry. Then it unrolls its proboscis, puts it into a flower, and sucks up sweet nectar.

A ground squirrel has strong teeth for cracking nuts and seeds. It carries food home in its cheeks and “squirrels” it away.

A baleen whale fills its mouth with seawater. The water is full of tiny plants and animals. The whale lets the water run out of its mouth. Then it swallows the plants and animals that remain.

Picture Credit : Google

What is an Animal?

Look closely at each pair of creatures. Can you tell which one is an animal and which one is a plant? You can’t always tell just by looking. Some plants look like animals, and some animals look like plants.

A sea anemone looks like a flower, but it is not. When a fish swims near it and touches the sea anemone’s petals, the fish gets caught. A little mouth opens up in the middle of the “flower” and grabs the fish! Plants don’t eat food the same way animals do. Most green plants make their own food with help from sunshine, air, and water. But animals can’t make their own food. So they eat plants or other animals.

The sea anemone slides slowly over the sand. Can a plant move around? No, it cannot. Once a plant sprouts up from its seed or roots, it stays in the same place. But most animals can get around by themselves. If a living thing moves about and eats food, it’s an animal.

Picture Credit : Google

How do animals move in different ways?

Animals Move

Animals can move in many different ways. They may waddle, swim, swoop, or hop. Some slither, others walk or run. A clam has only one foot for digging into mud or sand. A penguin walks on two legs. A dog walks or runs on four legs. Ladybugs walk on six legs. Spiders walk on eight legs. Centipedes may have a hundred pairs of legs to walk on, and some millipedes walk on more legs than that! Snakes and worms slither around on no legs at all. Bats and most kinds of birds and insects fly. And fish swim.

Some animals move only when they are very young. Barnacles, sponges, and baby oysters swim through the water until they find a good place to stay. Then they fasten themselves down and never move again.

Animals can move around without help. If a living thing moves by itself, it’s an animal.

Picture Credit : Google

What is unique about a snake’s jaw?

Now and then we come across news of snakes, pythons particularly, consuming animals unbelievably huge in proportion to their own size. So how do they do it? Come, let’s find out.

Snakes are found everywhere, except in the coldest regions. Which means their habitats are varied (water, soil, etc.), and so is their food. Depending on their size, these carnivores consume anything from earthworms and snails to birds, other snakes and alligators too! It’s the bigger snakes such as pythons and anacondas that go after larger animals such as deer, pigs, goats, crocodiles, and rarely, unsuspecting humans too. Irrespective of whether they kill their prey with venom or by constricting them, snakes invariably swallow their food as a whole. This applies to even their largest prey, and that’s where their jaws come into play.

No, the jaws don’t unhinge

The myth surrounding the snake’s consumption is that the reptile’s jaws unhinge to help it take in very large animals. Snakes have a set of skull bones, ligaments and muscles that help them stretch their mouths very wide. In addition, flexible joints in their jaws also help with elasticity. The jaws are attached by ligaments, making them very flexible while staying connected. Since snakes do not have limbs to hold their prey, their head and jaws come in handy to draw the prey in. Their inward-facing teeth too offer grip. Usually, snakes seem to be good judges when it con to the prey size they can take in. However, there have been unfortunate (and rare) instances of judgment going horribly wrong – resulting in two deaths.

Trivia: For all the (unwarranted) fear surrounding snakes, only a miniscule number is venomous. According to the National Geographic there are more than 3,000 species of snakes in the world, but only about 7% of them “are able to kill or significantly wound a human”.

 

Picture Credit : Google

Is there actually a blue moon?

You might have heard the idiom “Once in a blue moon” at some point in time. But is there actually a blue moon?

Rare and blue

Blue moon is used to refer to the third full moon in a season which has four full moons. Also called a seasonal blue moon, this occurs once in two-and-a-half years, making it a somewhat rare phenomenon. Today, however, a blue moon is also used to refer to the second full moon that appears in a month, which is also a rare occurrence.

A misunderstanding leads to a new definition

The seasonal definition for the term blue moon dates back to 1937. The August 1937 issue of the Maine Farmers’ Almanac explained that moon appears full 12 times in a year, three times each season. However, occasionally there will come a year that has 13 full moons. This means that one of the four seasons will have four full moons, instead of the usual three. The almanac followed certain rules for naming each full moon, such as the last full moon of winter had to fall during Lent and was called the Lenten Moon, while the first full moon of spring was called the Easter Moon and had to fall within the week before Easter.

Thus, when a particular season had four full moons, the third full moon was dubbed a blue moon so that the other full moons could occur at proper times relative to the solstices and equinoxes.

In March 1946, in an article titled “Once in a Blue Moon” which appeared in the Sky and Telescope magazine, the author misinterpreted the Maine Farmers’ Almanac and stated that in a year with 13 full moons, each of the months will have one full moon, while one will have two. However, this definition would mean the blue moon would appear in a different time than the seasonal blue moon since the seasonal blue moon was fixed based on solstices and equinoxes. But this monthly definition became popular after a radio programme in 1980 used this article as a source.

Has the moon ever appeared blue?

While a blue moon appears just like any other full moon, there have been cases where the moon has appeared bluish to the observer. The first major instance when this was observed was after the volcano Krakatoa erupted in 1883. The huge amounts of dust in the air acted as a filter causing sunsets and the moon to turn green and blue all over the world.

Sometimes events such as forest fires and dust storms can also cause the moon to appear bluish.

 

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What was the Stardust mission?

When returning from their famed moon mission in 1969, the astronauts of Apollo 11 returned with samples, including rocks, from our natural satellite. For decades after that, the only new material from space that geologists looked at came from meteorites reaching us. It was only in 2006 that a spacecraft sent material, including cometary and interstellar dust, back to Earth.

The Stardust mission was the first one to send back cometary samples and extraterrestrial material that came from outside the orbit of our moon. Launched in 1999, the Stardust spacecraft consisted of two solar arrays along with a sample return capsule that weighed 46 kg. It carried dedicated scientific and engineering instruments, which included the Cometary and Interstellar Dust Analyzer (CIDA), Dust Flux Monitor Instrument (DFMI), aerogel collector grid and navigation camera.

Substance called aerogel

Of these, the aerogel dust collector was of particular interest. The substance called aerogel was responsible for collecting the comet and interstellar dust. A silicon-based solid with a porous, sponge-like structure, it largely comprised empty space. Such a configuration enabled it to capture particles with minimum changes due to heat or chemical alteration, something impossible with conventional collection materials.

Before heading to the comet whose samples the spacecraft was scheduled to collect, it first visited an asteroid, 5535 Annefrank (named after Anne Frank, the Dutch-German diarist whose writings were published as The Diary of a Young Girl), in 2003. Flying within 3,300 km of the asteroid and clicking images of it, the flyby was seen as a preliminary run of what lay ahead for Stardust.

Wild encounter

By December 2003, Stardust was near its destination, comet 81P/ Wild, commonly known as Wild 2 (named after Swiss astronomer Paul Wild and pronounced “vilt 2”). It extended its tennis-racquet shaped collector, and after collecting all the material that was possible, sealed it in a vault in the re-entry capsule. It clicked a number of photographs as well and made its closest approach to the comet on January 2, 2004, flying within 250 km.

Two years later, in January 2006, Stardust released its conical capsule into the Earth’s atmosphere. The descent was stabilised by releasing a drogue parachute when 32 km out and the main parachute of the capsule opened up at a height of three km. After it touched down in the Utah desert helicopters arrived at the scene, picked up the capsule and transferred it to NASA’S Johnson Space Center in Houston within a couple of days. The search for signs of tiny little particles comic and interstellar dust – in the aerogel soon began.

What’s next?

Stardust, which was placed in hibernation after this phase of the mission was marked completed on January 16, 2006, got a new lease of life with an extended mission. Funding allowed for New Exploration of Tempel 1 (NEXT). after NASA’S Deep Impact had successfully observed the comet Tempel 1 in 2005 and also crash landed a probe on it.

The Stardust-NEXT mission was to continue mapping the comet and study how the impact crater changed. It reached its second comet target, Tempel 1, on February 14, 2011. While it became the first spacecraft to visit two comets in the process, Tempel 1 became the first come to be visited by two spacecraft.

The images and samples returned by Stardust helped us better understand comets, allowed researchers to discover a new class of organics more primitive than those found in meteorites and also helped identify irregular particles known as calcium-aluminium rich inclusions (CAIs) that are among the oldest solar system particles. A handful of interstellar particles too have been discovered and the search for more is still ongoing. Stardust’s extended mission ended on March 25, 2011 after which the spacecraft continues to orbit the sun. According to NASA’s predictions, it will never get closer than 2.7 million km to Earth’s orbit.

Ready to search for interstellar dust?

The sample returned by the Stardust spacecraft not only contained particles of various sizes collected from the comet Wild 2 but also rare and tiny interstellar dust particles.

While there are thousands of particles from the comet, the number of particles of interstellar dust are expected to be only in the 10s.

While this makes them incredibly rare and precious, it also makes the proverbial search for a needle in a haystack look easy.

As the search for interstellar dust would probably take researchers and scientists several years if they alone are involved in it they have started a Citizen Science Project Standust@home to crowdsource the search.

Through this project, they are seeking the support of talented volunteers from across the globe. If you are interested, you can also participate. You would. however, have to go through a web-based training session and pass a test before qualifying to register and participate.

If a volunteer discovers an interstellar dust particle, they appear as a co-author on scientific papers announcing the discovery, and also get the privilege of giving the particle its common name. Even if not that lucky, there is a ranking system based on the amount and quality of searching done with the top-ranked volunteers invited to visit the lab in Berkeley, the U.S.

 

Picture Credit : Google