Category Science

What are Voyager 1 and Voyager 2 programs?

In 1977, the U.S. space agency, NASA, launched an ambitious space programme-the Voyager-to study the four outer planets of the Solar System, namely Jupiter, Saturn, Uranus and Neptune. The mission employed two robotic probes, Voyager 1 and Voyager 2, on different trajectories. While the former was tasked to make a close flyby of Jupiter and Saturn, the latter was set to pass these planets on a wider trajectory, and explore Uranus and Neptune in addition. These spacecraft were initially designed to last only five years, but they outlived their expectations and their mission was subsequently extended. They continued their mission was subsequently extended. They continued their cosmic journey beyond the solar system into interstellar space.

It’s been 42 years since launch and both Voyager 1 and 2 are going strong and sending back data from more than 11 billion miles from the Sun. The track record is indeed outstanding, but the Voyager Program cannot go on forever. In 2019, NASA announced that both spacecraft will likely be retired by mid-2020s, as their power has been gradually dropping.

As if it was a sign of things to come, Voyager2 experienced a power glitch last month, which forced the spacecraft to go offline. But the NASA team fixed the problem and the probe’s science instruments resumed work.

In this week’s Five Ws & One H, let’s take a closer look at the Voyager Program and its monumental contributions to the field of astronomy.

 

Picture Credit : Google

Who is the closest relative of dodo bird?

Pigeons are here, there, everywhere, and are generally considered a nuisance. But, there’s one pigeon that draws gasps of admiration – and that’s the Nicobar pigeon (Caloenas nicobarica). It’s colourful plumage is what makes it so attractive. It also happens to be one of the largest pigeons and is the member of its genes. Also known as vulturine pigeon, hackled pigeon, or white-tailed pigeon, its bright plumage is a contrast to its close relative the dodo which is a dull grey. Nicobar pigeons birds are found only in some parts of the world – the Andaman and Nicobar islands in Southeast Asia. They usually avoid human contact and other predators, hence not much is known about the bird. Though one can spot them, they tend to breed on remote and uninhabited islands. Their behaviour is quite different from the other pigeons and doves.

Striking appearance

It has a sturdy body with a small head, long legs and wings, and a small white tail. Adults grow up to 16 inches and weigh about 1 pound. Females are heavier. The feathers on the head and the neck are blue-grey. The mane is covered with iridescent long purple hackles. The legs are purplish red in colour with long yellow claws. Their bills are black and hooked and have a black knob near the base. Body feathers are iridescent in shades of green, blue, hints of copper and gold. Males and females both have the same plumage, but the male is larger than the female and has brown iris, while the female has a white iris. Also, he females have a smaller knob on their bills.

Habitat

These pigeons are found mainly in South East Asia and the Pacific – from the Nicobar Islands to Thailand, Malaysia, Indonesia, the Philippines, and Papua New Guinea, the Solomon Islands, Palau, Myanmar, and the islands near Cambodia and Vietnam. They make their homes in forests and mangroves as they need a constant supply of food. They are nomadic by nature and fly from place to place within their range.

Food

Fruits, seeds, and small insects make up their meal. Their strong gizzard with its gizzard stone helps them feed on nuts with tough shells. The stone helps them grind up hard food items.

Raising the family

In the wild, these birds breed year-round, but in places where there is no human intervention. They are monogamous, and hence, mate for life. The male selects the nesting site and gathers all the required materials. The female then arranges them. Nests are pretty untidy and consist of twigs and dried leaves perched up in the trees. Sometimes there are several nests in a tree built by different members of a flock. The female lays only one egg per clutch, which hatches after a three-four weeks. The adults regurgitate their food and feed the chick crop milk. The fledglings get independent only after a month, but choose to stay in the nest for some more time. The young ones are dark coloured for around two years, and then they get the adult white tail. Nicobar pigeons live till they are 8 – 12 years in the wild and longer in captivity.

Conservation status

The species has been listed as “Near Threatened” by the IUCN because of dwindling forests, and because they are prey for cats and rats. Hunting of the birds by humans for food, the pet trade, and for their gizzard stones which are used as jewellery has also caused their numbers to decline.

Fascinating facts

  • These pigeons travel in large flocks of around 80-85 birds. During the day, they don’t mind the presence of humans, but at night, they prefer flying to uninhabited islands.
  • The birds’ white tail can be seen in flight. It guides other birds while flying at night or in the dark. Each bird follows the other’s tail while flying in a flock.
  • All pigeons suck up water similar to using a straw.
  • Some keep their neck plumage erect, during courtship or while displaying aggressive behaviour.
  • Nicobar pigeons are not very vocal, they normally coo. Only when they are scaring away predators do they make a sound that resembles a grunt.

 

Picture Credit : Google

Who invented the escalator?

The escalator is a moving staircase that helps people to move between floors at public places like malls, train, stations, airports etc.

The first idea of “revolving stairs” was patented by Nathan Ames in 1859 in USA, but it never saw the light of day. In the 1890s, American engineer Jesse W. Reno installed an “inclined elevator” at Coney Island, an amusement park in New York City. The 7-feet long conveyor belt was inclined at a 25 degree angle. It was the first example of a working escalator. The term ‘escalator’ was coined by Charles Seeberger, an American inventor, from the Latin word scala for steps and the word ‘elevator’, which had already been invented. He joined hands with the pioneering elevator company, Otis, and produced the first commercial wooden escalator which won the first prize at the Paris 1900 Exposition Universelle in France. Soon, escalators were installed in Europe and USA. As the Otis Elevator Company held the trademark rights to the word ‘escalator’ until 1950, other manufacturers called them by different names like Moving Stairs and Motorstair. Today, Otis and Schindler are the largest makers of escalators in the world.

 

Picture Credit : Google

What is a bookmark and its benefits?

The mention of the word “bookmark” brings to mind colourful designs. The bookmark offers a sense of comfort to those who find it difficult to trace the pages of the book they are reading. However, just as a bookmark lets you mark a page in a book, the feature lets you do the same online.

What is a bookmark?

Bookmarks are a feature offered by web browsers to pin webpages. While a physical bookmark lets you mark just one page of the book, the online feature enables you to pin several webpages.

You can bookmark as many webpages as you like and organise them into folders. However, a bookmark only stores the URL (Uniform Resource Locator). Meaning you can access a bookmarked page only when you are online. Besides, the contents of the bookmarked webpage can change.

Apart from saving and organising bookmarks, one can also export them.

How to bookmark pages and organise them

Bookmarking pages is a simple process. In most web browsers, next to the URL of the webpage, you can find a star icon. Just clicking on it will bookmark the page for you. Alternatively, you can visit the settings tab in your browser, select the bookmarks option and add the bookmark, or you could use the keyboard shortcut of Ctrl+D.

Once you have bookmarked a page, you can find it in the settings under bookmarks.

To remove a page from the bookmarks, go back to the setting and delete it from the bookmarks manager under bookmarks.

To organise your bookmarks, go to the bookmarks manager. Once there, you can choose the option to add a folder and name it as per your liking. The, drag and drop your bookmarks into it.

Meanwhile, when bookmarking a page, you can choose to save the bookmark in the folder of your choice.

Browsers also offer the option of exporting all your bookmarks to the computer. This option is available in the bookmarks manager.

What are the benefits?

Bookmarks can offer you quick access to the webpages you frequently visit. It can also serve as a memory bank that allows you to revisit a webpage you once liked.

Mostly, bookmarking sites can be beneficial when it comes to project work. Imagine you are working on a science project and visiting webpages that have relevant content. Instead of remembering the pages, you can create a folder in the bookmarks and add all the pages to it. This way, the next time you login, you can view all the pages easily from the bookmarks.

 

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Which are the tips to safeguard your privacy online?

Check your privacy setting

All social media sites have privacy settings. This can be found in your profile tab. By default, most settings are set to public, meaning anyone using the Internet can view what you post. But you can restrict this to just your friends by altering the settings. It is advisable to do so, as there are several people online waiting to prey on your data.

Use apps and messengers with end-to-end-encryption

When you use messaging services such as WhatsApp, you can notice a message which says your chats are end-to-end encrypted. This is a system of communication where only the users who are engaged in a chat can read the messages. What you share with each other cannot be preyed on by telecom companies or other providers waiting to use your data for targeted advertisements.

Hence, check for services and apps that have end-to-end encryption to maintain your privacy.

Don’t let websites track you

Certain web services and browsers allow websites to view and use information that your browser can reveal about your behavior. But the good news is that there are search engines and browsers available online for free that do not let websites track your data. Look for these and use them.

Don’t reveal personal data

If you don’t want random people calling, messaging or landing up at your door, keep your personal data private. Don’t reveal sensitive information online, even if your privacy settings are set to the maximum. Remember, your privacy is in your hands.

Antivirus to the rescue

An antivirus software is your best friend when it comes to privacy. It keeps hackers and data-preying sites and services at bay and ensures protection for your data and your system. So, remember to invest in a good one.

 

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What do sea pens do?

True to their names, sea pens resemble old-time quill writing pens. These colonial marine cnidarians (a large group of aquatic invertebrate animals) belong to the order Pennatulacea. Although the group is named for its supposed resemblance to antique quill pens, not all sea pen species live up to the comparison. Colours range from dark orange to yellow to white.

These underwater animals are actually a type of octocoral (soft coral), named for the eight stinging tentacles that they use to capture plankton (tiny floating plants and animals) to feed themselves. In fact, a single sea pen is both an individual and a colony. The basic unit of a sea pen, like all other corals, is a polyp, which consists of a sac-like body cavity enclosed by a mouth and surrounded by a ring of tentacles. The larva usually settles down in sand, mud, rubble or, sometimes, solid rock and this becomes the primary ployp. It buds into daughter polyps, and the sea pen grows. It is supported on a stem-like structure. While the larvae of some species settle close to their parents, others are carried great distances by ocean currents.

Some polyps feed by using nematocysts (a specialized cell in the tentacles of a jellyfish, corals and sea anemones, containing a barbed or venomous coiled thread that can be projected in self-defence or to capture prey) to catch plankton; some force polyps reproduce; and some force water in and out of canals that ventilate the colony.

Sea pens inhabit shallow and deep waters from the polar seas to the tropics. Some sea pens use a bulb inflated with water to anchor them to the sea floor. All have hard, internal skeletons, and at least some of them can glow in the dark.

Although many species live in shallow water, others have been found as deep as 20,013 feet (6,100 metres) below the surface. One species of Umbellula has been discovered living in cold, dark waters near Antarctica. It grows to about 10 feet (3 metres) long with a big, flat head of polyps at its end, the tentacles picking food out of the water as the head is pushed along by the current. Most sea pens, however, grow to between 2 inches and 6 feet, 7 inches (5 cm to 2 metres) in height.

 

Picture Credit : Google