My Science School

The fastest sea mammal in the world is the killer whale. With its streamlined body and powerful tail, it can speed through the water at up to 55 kph. That’s more than six times faster than the quickest human swimmers.

Is it true? Spinner dolphins spin like tops in the air.

Yes. Spinner dolphins are easy to recognize. They can leap out of the water, high into the air, and then spin around quickly like tops. These amazing acrobats live near the coast in warm seas.

Which is the speediest seal?

The fastest seal in the sea is the California sea lion, with a top speed of 40 kph. The fastest on land is the crabeater seal, reaching 19 kph over snow and ice.

Amazing! Some sea mammals can hold their breath for almost two hours before they have to come to the surface for air. Most humans can only hold their breath for a minute or so.

What is one of the deepest divers?

Sperm whales dive over two kilometres after their food. One sperm whale was even found with two deep-sea sharks in its stomach. It must have dived to three kilometres to catch them.

A walrus uses its long tusks to chip shellfish from rocks and break breathing holes in the ice. The males also use their tusks to fight off rivals and attract a mate.

Which seal blows up balloons?

To attract a mate or scare off a rival, a male hooded seal blows air into its nose! It can inflate the lining of one of its nostrils so that it looks like a big, red balloon.

Is it true? Seals cry when they are sad.

No. Seals sometimes look as if they’re crying, but it’s not because they’re sad. The tears keep their eyes moist and clean. In the sea, they get washed away. On land, they trickle down their cheeks.

Which seals live at the ends of the Earth?

Weddell seals live in the far south, on ice-covered islands off the coast of freezing Antarctica. Ringed seals live in the Arctic, at the other end of the world. They’ve been found as far north as the North Pole.

Amazing! In hot weather, some seals and sealions flip tiny pebbles and sand on to their backs with their flippers. This helps to keep them cool, and it also scratches them if their skin is feeling itchy.

Sea mammals spend most of their lives in or near the sea. There are three groups of sea mammals. Whales and dolphins are called cetaceans. Seals and walruses are called pinnipeds. Manatees and dugongs are called sirenians.

Amazing! There are well over 10 million crabeater seals living in the icy Antarctic. Seals are found in many parts of the world, but the southern crabeaters are the most common type of seal on Earth.

Which special features help whales live in the sea?

A whale’s body is designed for swimming. It has a smooth, streamlined shape for pushing through the water, and blowholes for breathing on top of its head.

Which is the biggest sea mammal?

The huge blue whale is the biggest mammal in the sea. In fact, it’s the biggest animal that has ever lived. It can grow more than 30 metres long and weigh as much as 130 tonnes.

Is it true? Whales once lived on land.

Yes. The ancestors of today’s whales once lived on land. About 50 million years ago, they went into the sea to look for food and their bodies adapted to life in the water.

Picture Credit : Google

Some whales have long, tough bristles, called baleen, hanging down inside their mouths, instead of teeth. They don’t chew their food, but sieve it from the water through the baleen.

Amazing! Whales have a thick layer of fat, called blubber under their skins. This keeps them warm in the cold sea. At about 50 centimetres, the bowhead whale has the thickest blubber.

Is it true? A whale uses its blowhole as a nose.

Yes. Like all mammals, whales must breathe air to stay alive. Instead of nostrils, they have a blowhole on top of the head.

What has tiny shellfish on its back?

Some whales have tonnes of tiny shellfish growing on their backs. The shellfish are called barnacles. They need to have a solid surface to glue their shells on to. And rock, ship or passing whale will do.

What’s the difference between whales and dolphins?

Strictly speaking, dolphins are small whales with sharp, pointed teeth for catching food. Dolphins live in seas all over the world. The biggest dolphin is the killer whale.

The term Blood Moon once was used in some sects of Christian prophecy to describe a total lunar eclipse that belonged to a tetrad of total lunar eclipses. The most recent Blood Moon – at least by this definition – took place on September 28, 2015. The next one won’t come until April 25, 2032.

The moon orbits around Earth, while Earth orbits around the sun. The moon takes about 27 days to orbit Earth and goes through regular phases in a 29.5-day cycle. The difference in these two cycles has to do with the relative positions of the sun, Earth and moon, which change during the moon's orbit.

Lunar eclipses can only happen during a full moon, when the sun fully illuminates the surface. Usually a full moon has no eclipse because the moon orbits in a slightly different plane than the Earth and the sun do. However, at times the planes coincide. Earth passes in between the moon and the sun and cuts off the sunlight, causing an eclipse.

 

Picture Credit : Google

Baade's Window is an area of the sky with relatively low amounts of interstellar "dust" along the line of sight from the Earth. This area is considered an observational "window" as the normally obscured Galactic Center of the Milky Way is visible in this direction. It is named for astronomer Walter Baade who first recognized its significance. This area corresponds to one of the brightest visible patches of the Milky Way.

Walter Baade observed the stars in this area in the mid-1940s using the 100-inch (2.5 m) Hooker telescope at Mount Wilson Observatory in California while searching for the center of the Milky Way galaxy. Up until this time the structure and location of the galactic center was not known with certainty.

In 2006, the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS) conducted an astronomical survey to monitor 180,000 stars for seven days to detect extrasolar planets via the transit method.

Baade's Window is frequently used to study distant central bulge stars in visible and near-visible wavelengths of light. Important information on the internal geometry of the Milky Way is still being refined by measurements made through this "window". It is in the direction of the constellation of Sagittarius. The window is now known to be slightly "south" of the main central galaxy bulge. The window is irregular in outline and subtends about 1 degree of the sky. It is centered on the globular cluster NGC 6522.

 

Picture Credit : Google