My Science School

 

Vesuvius is the only active volcano in mainland Europe, and has produced some of the continent's largest volcanic eruptions. Located on Italy's west coast, it overlooks the Bay and City of Naples and sits in the crater of the ancient Somma volcano. Vesuvius is most famous for the 79 AD eruption which destroyed the Roman cities of Pompeii and Herculaneum. Though the volcano's last eruption was in 1944, it still represents a great danger to the cities that surround it, especially the busy metropolis of Naples.

Vesuvius is part of the Campanian volcanic arc, a line of volcanoes that formed over a subduction zone created by the convergence of the African and Eurasian plates. This subduction zone stretches the length of the Italian peninsula, and is also the source of other volcanoes like Mount Etna, the Phlegraean Fields (Campi Flegrei), Vulcano, and Stromboli. Under Vesuvius, the lower part of the subducting slab has torn and detached from the upper part to form what is called a "slab window." This makes Vesuvius' rocks slightly different chemically from the rocks erupted from the other Campanian volcanoes.

The cone known as Mount Vesuvius began growing in the caldera of the Mount Somma volcano, which last erupted about 17,000 years ago. Most rocks erupted from Vesuvius are andesite, an intermediate volcanic rock (about 53-63% silica). Andesite lava creates explosive eruptions on a variety of scales, which makes Vesuvius an especially dangerous and unpredictable volcano. Strombolian eruptions (explosions of magma from a pool in the volcano’s conduit) and lava flows from the summit and flank fissures are relatively small. Plinian eruptions (huge explosions that create columns of gas, ash and rock which can rise dozens of kilometers into the atmosphere) have a much greater reach, and have destroyed entire ancient cities near Vesuvius with huge ashfalls and pyroclastic flows. Vesuvius is currently quiet, with only minor seismic (earthquake) activity and outgassing from fumaroles in its summit crater, but more violent activity could resume in the future.

Credit : Geology.com

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Vulture is a bird of prey. The Old World vultures include 15 living species native to Europe, Africa, and Asia; and New World vultures are restricted to North and South America. Most of the species have a bald head, and a neck devoid of feathers.

It has a strong, sharp and hooked beak and a long wingspan, which allows it to stay in flight for long periods of time, without flapping my wings. It scavenges on carrion and sometimes feeds on newborn and wounded animals. It can go without food for days and when it does find something to eat, it has its fill.

It has a throat pouch called a crop, which is used to store food to be consumed later or to feed young ones. It has strong stomach acid, which allows it to safely digest decaying carcasses.

It is a myth that vultures circle dying animals waiting to feed. These birds are powerful fliers and soar on thermals (columns of rising air) while they look for food, but they cannot sense when an animal is dying. When they locate a carcass by smell, sight, or the sound of other birds feeding, they approach it quickly before other predators find it.

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Cuscus is a marsupial that lives in Australia, Papua New Guinea, Indonesia and on the nearby islands. It can survive in tropical rainforests, mangroves and dense forests at high altitudes.

Its body is covered with thick, woolly fur that can be black, brown, white, tan or grey in colour. The fur can be covered with spots. It has a rounded head with small ears and large eyes. Its eyes are adapted for night vision.

It lives on treetops and eats leaves, nectar, flowers and fruits. Sometimes, it eats small animals, and occasionally eggs. Pythons, hawks and owls are its predators. It is a shy and territorial animal.

Common spotted cuscus natural habitat comprises rainforests with trees like mangroves and eucalyptus. Cuscus who lives in the mangroves will migrate to the tropical forest during the winters. Cuscuses create their habitat in hollow trees. They also tend to create a platform on branches of a tree for resting during the day. Common spotted cuscus can be found sleeping under a canopy of leaves when the weather gets really hot. During summer time, they prefer resting inside a hollow log of tree. They prefer living in regions where their food requirements are taken care of by easy availability of fruit.

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Humans have not set foot on the moon for nearly 50 years, but the Apollo moon missions aren’t over. The echoes from Neil Armstrong’s first steps are still helping scientists make giant leaps in understanding the moon’s geology.

When Apollo 17 packed up for home in 1972, the astronauts brought rock samples with them. NASA locked many of the rocks and core samples away in a vault, awaiting technological innovations that would allow future scientists to study them better than 1970s technology allowed.

Now, Purdue University scientists including Michelle Thompson, an assistant professor of Earth, Atmospheric and Planetary Sciences in Purdue’s College of Science, and Marc Caffee, professor of physics and astronomy with a courtesy appointment in the Department of Earth, Atmospheric, and Planetary Sciences, are both working on teams that will analyze some of the moon rocks and lunar soil samples from that mission.

Thompson and her team are partnering with some of the original scientists, including Harrison “Jack” Schmitt, the first and only geologist ever to walk on the moon, to learn more about the moon itself through the rock samples.

Credit : Purdue 

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Our Milky Way galaxy is a big place. Even at this blazing speed, it takes the sun approximately 225-250 million years to complete one journey around the galaxy’s center.

This amount of time – the time it takes us to orbit the center of the galaxy – is sometimes called a cosmic year.

By the way, in the past when we’ve talked about this subject, people have commented on the difference between the words rotate and revolve. The word revolve means to orbit around another body. Earth revolves (or orbits) around the sun. The sun revolves around the center of the Milky Way galaxy.

On the other hand, rotate means to spin on an axis. The Earth rotates every 24 hours. The sun rotates, but not at a single rate across its surface. The movements of the sunspots indicate that the sun rotates once every 27 days at its equator, but only once in 31 days at its poles.

The planets in our solar system orbit (revolve) around the sun, and the sun orbits (revolves) around the center of the Milky Way galaxy. We take about 225-250 million years to revolve once around the galaxy’s center. This length of time is called a cosmic year.

Credit : Earth Sky 

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Jupiter is the fastest spinning planet in our Solar System rotating on average once in just under 10 hours. That is very fast especially considering how large Jupiter is. This means that Jupiter has the shortest days of all the planets in the Solar System. 

Jupiter is the 5th planet from the sun and it is the biggest of all planets in the solar system. It is a giant gaseous planet and about 2.5 times the size of all planets combined in the solar system. It spins on its axis in the opposite direction as opposed to most planets. Other gas planets include Saturn, Uranus, and Neptune. Jupiter is believed to have a solid core made of rocks. Like most other planets, Jupiter does not have a defined solid surface. As a result of its rotation, the planet has an oblate spheroid shape having a bulge along the equator. The atmosphere of the planet is divided into different bands that vary with the altitude. At the boundaries are great turbulence and storms and the popular one is the Great Red Spot; a giant storm, which was first observed in the 17th century using a telescope. Because the surface of the planet is not solid, the rotational speed around the equator is different from that of its polar areas, and this is why it has a bulge at its equator. The rotational speed at the equator of this planet is 28,273 miles per hour. A complete day in Jupiter around the poles is an estimated nine hours and 56 minutes while at the equator it is an estimated nine hours and 50 minutes.

Jupiter is made up of 92% hydrogen and 8% of helium in the volume by gas composition, while by mass, its atmosphere is comprised of about of 75% hydrogen and 25% helium. In comparison to the planet Earth, Jupiter is massive but has low density. Jupiter has three rings around it and other moons, which orbit around it as well. The planet has faint narrow rings, which are dark and made of dust and rock fragments. Unlike the rings of Saturn, the rings of Jupiter are constantly losing materials and being replenished with the dust from other tiny meteors hitting the four inner moons. Jupiter has about 69 moons, which include four large moons that were discovered in 1610 by Galileo and they are known as Galilean moons. The largest of the four moons is the Ganymede, which has a larger diameter than planet Mercury. The Jupiter’s rings have three sections namely halo, main, and Gossamer rings.

Credit : World Atlas 

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Moons — also called natural satellites — come in many shapes, sizes and types. They are generally solid bodies, and few have atmospheres. Most planetary moons probably formed from the discs of gas and dust circulating around planets in the early solar system.

Earth's Moon probably formed when a large body about the size of Mars collided with Earth, ejecting a lot of material from our planet into orbit. Debris from the early Earth and the impacting body accumulated to form the Moon approximately 4.5 billion years ago (the age of the oldest collected lunar rocks). Twelve American astronauts landed on the Moon during NASA's Apollo program from 1969 to 1972, studying the Moon and bringing back rock samples.

Usually the term moon brings to mind a spherical object, like Earth's Moon. The two moons of Mars, Phobos and Deimos, are different. While both have nearly circular orbits and travel close to the plane of the planet's equator, they are lumpy and dark. Phobos is slowly drawing closer to Mars and could crash into the planet in 40 or 50 million years. Or the planet's gravity might break Phobos apart, creating a thin ring around Mars.

Credit : NASA Science 

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China and Russia have agreed to jointly build a research station on or around the moon, setting the stage for a new space race.

The United States and the Soviet Union, followed by its successor state, Russia, have long dominated space exploration, putting the first astronauts in space and on the moon and later collaborating on the International Space Station that has been in orbit for two decades.

The joint announcement by China and Russia on Tuesday has the potential to scramble the geopolitics of space exploration, once again setting up competing programs and goals for the scientific and, potentially, commercial exploitation of the moon. This time, though, the main players will be the United States and China, with Russia as a supporting player.

In recent years, China has made huge advances in space exploration, putting its own astronauts in orbit and sending probes to the moon and to Mars. It has effectively drafted Russia as a partner in missions that it has already planned, outpacing a Russian program that has stalled in recent years.

Credit : The New York Times 

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Semmelweis observed that, among women in the first division of the clinic, the death rate from childbed fever was two or three times as high as among those in the second division, although the two divisions were identical with the exception that students were taught in the first and midwives in the second. He put forward the thesis that perhaps the students carried something to the patients they examined during labour. The death of a friend from a wound infection incurred during the examination of a woman who died of puerperal infection and the similarity of the findings in the two cases gave support to his reasoning. He concluded that students who came directly from the dissecting room to the maternity ward carried the infection from mothers who had died of the disease to healthy mothers. He ordered the students to wash their hands in a solution of chlorinated lime before each examination.

Under these procedures, the mortality rates in the first division dropped from 18.27 to 1.27 percent, and in March and August of 1848 no woman died in childbirth in his division. The younger medical men in Vienna recognized the significance of Semmelweis’ discovery and gave him all possible assistance. His superior, on the other hand, was critical—not because he wanted to oppose him but because he failed to understand him.

Semmelweis’ doctrine was subsequently accepted by medical science. His influence on the development of knowledge and control of infection was hailed by Joseph Lister, the father of modern antisepsis: “I think with the greatest admiration of him and his achievement and it fills me with joy that at last he is given the respect due to him.”

Credit : Britannica 

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