My Science School

Researchers have sequenced the complete genomes of hundreds of animals and plants-more than 250 animal species and 50 species of birds alone-and the list continues to grow almost daily.

In addition to the sequencing of the human genome, which was completed in 2003, scientists involved in the Human Genome Project sequenced the genomes of a number of model organisms that are commonly used as surrogates in studying human biology. These include the rat, puffer fish, fruit fly, sea squirt, roundworm, and the bacterium Escherichia coli. For some organisms NHGRI has sequenced many varieties, providing critical data for understanding genetic variation.

DNA sequencing centers supported by NHGRI also have sequenced genomes of the chicken, dog, honey bee, gorilla, chimpanzee, sea urchin, fungi and many other organisms.

Picture Credit : Google

Biomimetic refers to human-made processes, substances, devices, or systems that imitate nature.

The art and science of designing and building biomimetic apparatus is also known as biomimicry because they mimic biological systems. The field is of special interest to researchers in nanotechnology, robotics, artificial intelligence (AI), the medical industry, and the military.

Living organisms have evolved well-adapted structures and materials over geological time through natural selection. Biomimetics has given rise to new technologies inspired by biological solutions at macro and nanoscales. Humans have looked at nature for answers to problems throughout our existence. Nature has solved engineering problems such as self-healing abilities, environmental exposure tolerance and resistance, hydrophobicity, self-assembly, and harnessing solar energy.

Picture Credit : Google

Synthetic biology (SynBio) is a multidisciplinary area of research that seeks to create new biological parts, devices, and systems, or to redesign systems that are already found in nature.

It is a branch of science that encompasses a broad range of methodologies from various disciplines, such as biotechnology, genetic engineering, molecular biology, molecular engineering, systems biology, membrane science, biophysics, chemical and biological engineering, electrical and computer engineering, control engineering and evolutionary biology.

Due to more powerful genetic engineering capabilities and decreased DNA synthesis and sequencing costs, the field of synthetic biology is rapidly growing. In 2016, more than 350 companies across 40 countries were actively engaged in synthetic biology applications; all these companies had an estimated net worth of $3.9 billion in the global market.

Studies in synthetic biology can be subdivided into broad classifications according to the approach they take to the problem at hand: standardization of biological parts, biomolecular engineering, genome engineering, metabolic engineering.

Picture Credit : Google

On November 3, 1957, less than a month after they inaugurated the Space Age, the Soviet Union took the next big step with the launch of Sputnik 2.  Hurriedly prepared to take advantage of the propaganda value of the first satellite, Sputnik 2 utilized an animal habitat and carried the dog Laika, the first animal to orbit the Earth.

Sputnik 2 weighed 508 kg, significantly more than its simpler predecessor, and remained attached to its booster rocket after achieving orbit.  Due to the lack of adequate development time, no provisions were made to recover Laika.  Engineers had not designed the environmental control system for a lengthy mission and it is likely that Laika only survived for a few hours after reaching orbit.  On November 10, the satellite’s batteries expired, and receipt of data from the science experiments also ceased.  Sputnik 2 burned up on reentry on April 14, 1958.  It would be nearly three years before the Soviet Union orbited more animals, this time returning the entire “crew” safely to Earth, the first steps in preparation for human space flight.

Laika was a young, mostly-Siberian husky. She was rescued from the streets of Moscow. Soviet scientists assumed that a stray dog would have already learned to endure harsh conditions of hunger and cold temperatures. Laika and two other dogs were trained for space travel by being kept in small cages and learning to eat a nutritious gel that would be their food in space.

The dog's name was originally Kudryavka, or Little Curly, but she became known internationally as Laika, a Russian word for several breeds of dog similar to a husky. American reporters dubbed her Muttnik as a pun on Sputnik.

Unfortunately, Laika's trip into space was one-way only. A re-entry strategy could not be worked out in time for the launch. It is unknown exactly how long Laika lived in orbit — perhaps a few hours or a few days — until the power to her life-support system gave out. Sputnik 2 burned up in the upper atmosphere in April 1958.

Picture Credit : Google

Yuri Gagarin was the first person to fly in space. His flight, on April 12, 1961, lasted 108 minutes as he circled the Earth for a little more than one orbit in the Soviet Union's Vostok spacecraft. Following the flight, Gagarin became a cultural hero in the Soviet Union. Even today, more than six decades after the historic flight, Gagarin is widely celebrated in Russian space museums, with numerous artifacts, busts and statues displayed in his honor. His remains are buried at the Kremlin in Moscow, and part of his spacecraft is on display at the RKK Energiya museum.

More than 200 Russian Air Force fighter pilots were selected as cosmonaut candidates. Such pilots were considered optimal because they had exposure to the forces of acceleration and the ejection process, as well as experience with high-stress situations. Gagarin, a 27-year-old senior lieutenant at the time, was among the pilots selected.

On April 12, 1961, at 9:07 a.m. Moscow time, the Vostok 1 spacecraft blasted off from the Soviets' launch site. Because no one was certain how weightlessness would affect a pilot, the spherical capsule had little in the way of onboard controls; the work was done either automatically or from the ground. If an emergency arose, Gagarin was supposed to receive an override code that would allow him to take manual control, but Sergei Korolev, chief designer of the Soviet space program, disregarded protocol and gave the code to the pilot prior to the flight.

Over the course of 108 minutes, Vostok 1 traveled around the Earth once, reaching a maximum height of 203 miles (327 kilometers). The spacecraft carried 10 days' worth of provisions in case the engines failed and Gagarin was required to wait for the orbit to naturally decay. But the supplies were unnecessary. Gagarin re-entered Earth's atmosphere, managing to maintain consciousness as he experienced forces up to eight times the pull of gravity during his descent.

Vostok 1 had no engines to slow its re-entry and no way to land safely. About 4 miles (7 km) up, Gagarin ejected from the spacecraft and parachuted to Earth. In order for the mission to be counted as an official spaceflight, the Fédération Aéronautique Internationale (FAI), the governing body for aerospace records, had determined that the pilot must land with the spacecraft. Soviet leaders indicated that Gagarin had touched down with the Vostok 1, and they did not reveal that he had ejected until 1971. Regardless, Gagarin still set the record as the first person to leave Earth's orbit and travel into space.

Picture Credit : Google

On June 16, 1963, aboard Vostok 6, Soviet Cosmonaut Valentina Tereshkova becomes the first woman to travel into space. After 48 orbits and 71 hours, she returned to earth, having spent more time in space than all U.S. astronauts combined to that date.

In 1963, Tereshkova was chosen to take part in the second dual flight in the Vostok program, involving spacecrafts Vostok 5 and Vostok 6. On June 14, 1963, Vostok 5 was launched into space with cosmonaut Valeri Bykovsky aboard. With Bykovsky still orbiting the earth, Tereshkova was launched into space on June 16 aboard Vostok 6. The two spacecrafts had different orbits but at one point came within three miles of each other, allowing the two cosmonauts to exchange brief communications. Tereshkova’s spacecraft was guided by an automatic control system, and she never took manual control. On June 19, after just under three days in space, Vostok 6 reentered the atmosphere, and Tereshkova successfully parachuted to earth after ejecting at 20,000 feet. Bykovsky and Vostok 5 landed safely a few hours later.

After her historic space flight, Valentina Tereshkova received the Order of Lenin and Hero of the Soviet Union awards. In November 1963, she married fellow cosmonaut Andrian Nikolayev, reportedly under pressure from Soviet leader Nikita Khrushchev, who saw a propaganda advantage in the pairing of the two single cosmonauts. The couple made several goodwill trips abroad, had a daughter, and later separated. In 1966, Tereshkova became a member of the Supreme Soviet, the USSR’s national parliament, and she served as the Soviet representative to numerous international women’s organizations and events. She never entered space again, and hers was the last space flight by a female cosmonaut until the 1980s.

Picture Credit : Google

Apollo 11 was the spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin formed the American crew that landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC (14:17 CST). Armstrong became the first person to step onto the lunar surface six hours and 39 minutes later on July 21 at 02:56 UTC; Aldrin joined him 19 minutes later. They spent about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds (21.5 kg) of lunar material to bring back to Earth. Command module pilot Michael Collins flew the Command Module Columbia alone in lunar orbit while they were on the Moon's surface. Armstrong and Aldrin spent 21 hours, 36 minutes on the lunar surface, at a site they had named Tranquility Base upon landing, before lifting off to rejoin Columbia in lunar orbit.

After being sent to the Moon by the Saturn V's third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit. Armstrong and Aldrin then moved into Eagle and landed in the Sea of Tranquility on July 20. The astronauts used Eagle's ascent stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that propelled Columbia out of the last of its 30 lunar orbits onto a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24 after more than eight days in space.

Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience. He described the event as "one small step for man, one giant leap for mankind." Apollo 11 effectively proved US victory in the Space Race to demonstrate spaceflight superiority, by fulfilling a national goal proposed in 1961 by President John F. Kennedy, "before this decade is out, of landing a man on the Moon and returning him safely to the Earth”.

Picture Credit : Google

G. N. Lewis was born in 1875 in Weymouth, Massachusetts. After receiving his PhD in chemistry from Harvard University and studying abroad in Germany and the Philippines, Lewis moved to California in 1912 to teach chemistry at the University of California, Berkeley, where he became the Dean of the College of Chemistry and spent the rest of his life. As a professor, he incorporated thermodynamic principles into the chemistry curriculum and reformed chemical thermodynamics in a mathematically rigorous manner accessible to ordinary chemists. He began measuring the free energy values related to several chemical processes, both organic and inorganic. In 1916, he also proposed his theory of bonding and added information about electrons in the periodic table of the chemical elements. In 1933, he started his research on isotope separation. Lewis worked with hydrogen and managed to purify a sample of heavy water. He then came up with his theory of acids and bases, and did work in photochemistry during the last years of his life.

Though he was nominated 41 times, G. N. Lewis never won the Nobel Prize in Chemistry, resulting in a major Nobel Prize controversy. On the other hand, Lewis mentored and influenced numerous Nobel laureates at Berkeley including Harold Urey (1934 Nobel Prize), William F. Giauque (1949 Nobel Prize), Glenn T. Seaborg (1951 Nobel Prize), Willard Libby (1960 Nobel Prize), Melvin Calvin (1961 Nobel Prize) and so on, turning Berkeley into one of the world's most prestigious centers for chemistry. On March 23, 1946, Lewis was found dead in his Berkeley laboratory where he had been working with hydrogen cyanide; many postulated that the cause of his death was suicide. After Lewis' death, his children followed their father's career in chemistry, and the Lewis Hall on the Berkeley campus is named after him.

Picture Credit : Google

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding. For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full valence shell, corresponding to a stable electronic configuration. In organic chemistry, covalent bonds are much more common than ionic bonds.

Atomic orbitals (except for s orbitals) have specific directional properties leading to different types of covalent bonds. Sigma bonds are the strongest covalent bonds and are due to head-on overlapping of orbitals on two different atoms. A single bond is usually a sigma bond. Pi bonds are weaker and are due to lateral overlap between p (or d) orbitals. A double bond between two given atoms consists of one sigma and one pi bond, and a triple bond is one sigma and two pi bonds.

Covalent bonds are also affected by the electronegativity of the connected atoms which determines the chemical polarity of the bond. Two atoms with equal electronegativity will make nonpolar covalent bonds such as H–H. An unequal relationship creates a polar covalent bond such as with H?Cl. However polarity also requires geometric asymmetry, or else dipoles may cancel out resulting in a non-polar molecule.

Picture Credit : Google

According to the International Astronomical Union (IAU), a dwarf planet is a celestial body that is in orbit around a star: massive enough to be rounded by its own gravity: but has not cleared the neighbourhood around its orbit, and is not natural satellite.

The key difference between a planet and a dwarf planet is that a dwarf planet has not become gravitationally dominant enough to clear the neighbourhood around its orbit. In other words, it shares its orbital space with other celestial bodies of similar size. There are five recognised dwarf planets in our solar system - Pluto, Ceres, Haumea, Makemake and Eris. Pluto was earlier classified as a planet, but it was stripped of its status in 2006, when the IAU formalised the definition of a planet and a dwarf planet. Pluto orbits in a disc-like zone beyond the orbit of Neptune called the Kuiper Belt, a region populated with frozen bodies left over from the solar system's formation.

Picture Credit : Google

Venus is often referred to as Earth’s twin. Both the planets are almost alike in size, density and gravity. Despite similar physical makeup, like most siblings we know of, the two worlds turned out to be drastically different from each other. While Earth is a heaven for life, Venus is a blistering hellscape. Venus has a thick, toxic atmosphere filled with carbon dioxide and at 850 degrees Fahrenheit, it is the hottest planet in the solar system. It has a crushing air pressure and is perpetually shrouded in thick, yellowish clouds of sulphuric acid.

Though Venus was the first ever planet to be explored by a spacecraft (Russia’s Venera 1 in 1961), space agencies have largely ignored Venus in the last few decades and focussed on other planets, especially Mars.

But that’s set to change with NASA, the U.S. Space Agency, announcing two robotic missions to Venus as part of the Discovery Program. Recent studies, one suggesting that the planet's surface was habitable for several billion years, and another suggesting presence of microbes in Venusian skies, have reinvigorated an interest in Venus.

Set to be launched in 2028-2030 time period, the NASA missions will include an orbiter called VERITAS and an atmospheric probe known as DAVINCI+. The price tag of each mission is capped at around $500 million. Read on to know more about these missions...

What is DAVINCI+?

• Probe DAVINCI+, which stands for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging, will gather more detail on the composition of Venus' atmosphere to learn how it formed and evolved.
• The mission also seeks to determine whether the planet once had an ocean.
• A descent sphere will plunge through the dense atmosphere which is laced with sulphuric acid clouds. It will precisely measure the levels of noble gases and other elements to learn what gave rise to the runaway greenhouse effect we see today.
• DAVINCI+ will also beam back the first high resolution images of the planet's ‘tesserae,’ geological features roughly comparable with Earth's continents whose existence suggests Venus has plate tectonics.
• The results could reshape scientists' understanding of terrestrial planet formation.

What is the objective of VERITAS?

• The other mission is called VERITAS, an acronym for Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy.
• This will aim to map the Venusian surface from orbit and delve into the planet's geologic history.
• Using a form of radar that is used to create three-dimensional constructions, it will chart surface elevations and confirm whether volcanoes and earthquakes are still happening on the planet.
• It will also use infrared scanning to determine rock type, which is largely unknown, and whether active volcanoes are releasing water vapour into the atmosphere.
• While the mission is NASA led, the German Aerospace Center will provide the infrared mapper. The Italian Space Agency and France's Centre National d'Etudes Spatiales will contribute to the radar and other parts of the mission.

What are some of the previous missions to Venus?

• Russia (former Soviet Union) launched a number of missions to Venus under its Venera program between 1961 and 1984. Its Venus program achieved some of the greatest successes of human space exploration—including the first landing of spacecraft on another planet and the first photos from another world’s surface.
• The first one to launch was Venera 1, which made a flyby in May 1961, however no data returned due to communication failure. Subsequently, ten probes successfully landed on the surface of the planet, including the two Vega program and Venera-Halley probes, while thirteen probes successfully entered the Venusian atmosphere.
• Venera 13 survived the intense heat and crushing pressure of Venus’ surface for more than two hours, while others survived only for a few minutes. Most atmospheric information and surface data from Venus were collected by the Soviet Union.
• NASA's Mariner 2 successfully flew by and scanned the cloud-covered world in 1962. NASA’s last Venus orbiter was Magellan, which arrived in 1990, and mapped the planet's surface with radar. Since then, numerous spacecraft from the U.S. (and other space agencies) have flew by Venus as part of their missions to other destinations. These include Galileo to Jupiter in 1990, Cassini-Huygens to Saturn in 1998/99 and NASA's MESSENGER mission to Mercury in 2006 and 2007.
• European Space Agency’s Venus Express Orbiter entered Venus orbit on April 2006 and the communication was lost in November 2014. Japan’s Akatsuki space probe tasked to study the atmosphere of Venus entered Venus orbit in 2015 and is still operational.

Why is there a renewed interest in Venus?

• Scientists think that Venus was once a balmy, temperate world with oceans, rivers and streams. Recent research suggests that Venus was habitable for life for several billion years, until greenhouse effect took hold around 700 million years ago.
• Another research suggests that Venus may be habitable today. Scientists theorise microbes might exist high in the clouds where it’s cooler and the pressure is similar to Earth’s surface. Detection of phosphine, a chemical released by microbes, suggested that life was possible in the clouds of Venus. The apparent phosphine find has not been confirmed by other teams, however, and remains a topic of considerable discussion and debate.
• So Venus has become an attractive target for extraterrestial study.
• Scientists studying exoplanets are trying to understand the Venus-Earth difference to know about how planets evolve in general, and how habitable conditions evolve.

How does future look like for Venus exploration?

• India is developing a potential Venus mission. Shukrayaan-1 is a proposed orbiter to Venus to be launched in 2024 or 2026. The project would include an orbiter and an atmospheric balloon probe and study the surface and atmosphere of the planet.
• Russia aims to go back to Venus with an ambitious mission called Venera-D that would feature an orbiter, a lander and atmospheric balloons. Venera-D will launch in 2029, if all goes according to plan.
• Rocket Lab, a private space agency, plans to launch a Venus mission in 2023 using its Electron rocket and Photon satellite bus.
• EnVision is an orbital mission to Venus being developed by the European Space Agency and proposed to be launched in 2023.

Picture Credit : Google

A star like our Sun will become a white dwarf when it has exhausted its nuclear fuel. Near the end of its nuclear burning stage, such a star expels most of its outer material (creating a planetary nebula) until only the hot (T > 100,000 K) core remains, which then settles down to become a young white dwarf. A typical white dwarf is half as massive as the Sun, yet only slightly bigger than the Earth. This makes white dwarfs one of the densest forms of matter, surpassed only by neutron stars.

White dwarfs have no way to keep themselves hot (unless they accrete matter from other closeby stars); therefore, they cool down over the course of many billions of years. Eventually, such stars cool completely and become black dwarfs. Black dwarfs do not radiate at all.

Many nearby, young white dwarfs have been detected as sources of soft X-rays (i.e. lower-energy X-rays); soft X-ray and extreme ultraviolet observations enable astronomers to study the composition and structure of the thin atmospheres of these stars.

Picture Credit : Google

An annular solar eclipse happens when the Moon covers the Sun's center, leaving the Sun's visible outer edges to form a “ring of fire” or annulus around the Moon.

The name “annular” comes from the Latin word for ring, “annulus.” These eclipses are named for their darkest, or maximum, point even if it only lasts less than a second. If the characteristic ring of fire is visible from even just one location, the whole eclipse is called an annular solar eclipse.

However, in most places and for most of the duration, an annular eclipse looks like a partial solar eclipse. This is also the case for total solar eclipses and for the rare hybrid solar eclipses which have an annular maximum point in some locations and a total maximum point in other locations.

Picture Credit : Google

The uppermost portion of the Sun's atmosphere is called the corona, and is surprisingly much hotter than the Sun's surface (photosphere)! The upper corona gradually turns into the solar wind, a flow of plasma that moves outward through our solar system into interstellar space. The solar wind is, in a sense, just an extension of the Sun's atmosphere that engulfs all of the planets. Earth actually orbits within the atmosphere of a star!

Temperatures rise sharply in the transition region, from thousands of degrees in the chromosphere to more than a million degrees in the corona. The density of plasma falls rapidly through the transition region moving upward from the chromosphere to the corona.

We normally cannot see the solar atmosphere, including the corona. The surface of the Sun is far too bright to allow a glimpse of the much fainter corona. During a total solar eclipse the wispy corona briefly comes into view as the Moon blocks out the solar surface. A special instrument called a coronagraph allows astronomers to view the corona at other times. Some coronagraphs are used with ground-based telescopes; others are carried on satellites.

Picture Credit : Google

The visible surface of the sun, or the photosphere, is around 6,000 degrees Celsius (11,000 degrees Fahrenheit). But a few thousand kilometers above it – a small distance when we consider the size of the sun – the solar atmosphere, also called the corona, is hundreds of times hotter. The corona reaches a million degrees C or higher (over 1.8 million degrees F).

Although there was little doubt that part of the energy from the Sun's interior reached its outer layers, the exact mechanism remained a mystery. The researchers concentrated on the small-scale magnetic field, which, except for the sunspots, has a 'salt-and-pepper' appearance.

Using powerful numerical models run on computers at the Centre de Physique Théorique and GENCI at IDRIS-CNRS, the team performed a simulation for several hours, based on a model made up of several layers, one inside the Sun and the others in its atmosphere. The researchers observed that the thin layer under the Sun's surface actually behaves rather like a shallow pan containing boiling plasma[2], heated from below and forming 'bubbles' associated with granules. This boiling plasma soup generates a dynamo process that amplifies and maintains the magnetic field. As the field emerges from the surface, it takes on a salt-and-pepper appearance, forming concentrations dubbed 'mesospots' that are larger, fewer in number and more persistent, all of which is consistent with observations.

The researchers' calculations show that, in the chromosphere, heating of the atmosphere results from multiple micro-eruptions in the mangrove roots that carry intense electric current, in pace with the 'bubbles' from the boiling plasma. They also discovered that larger but less numerous eruptive events take place in the neighborhood of the mesospots, although these are not able to heat the upper corona on a larger scale.

Picture Credit : Google