Thursday, October 1, 2020

does life exist in Venus .. some facts !!

 

The Milky Way Galaxy resides in a neighborhood of a few dozen galaxies called the Local Group. They range in size from small dwarf galaxies to the large Andromeda Galaxy. Over time, these galaxies interact with one another, changing their motions and shapes. The long-term evolution of a galaxy is influenced by being part of a group. The Milky Way and the Andromeda Galaxy, our nearest spiral neighbor, are headed toward each other. In about five billion years, they may collide and merge. Eventually, our remote descendants could be living in a large elliptical galaxy.

The ultimate aim, fear, curiosity, research, thought, goal of  humanity perhaps is in finding out whether there exists life outside our planet – are there any neighbours living in any nearby planet, galaxy or elsewhere.  NASA's exoplanet program is to find unmistakable signs of current life on a planet beyond Earth. How soon that can happen depends on two unknowns: the prevalence of life in the galaxy and how lucky we get as we take those first, tentative, exploratory steps.

Nothing about 2020 surprises us anymore. It has been the year of pandemics, wildfires, asteroids zooming past Earth and now, aliens.  Scientists said on Monday that they have detected in the harshly acidic clouds of Venus, a gas called phosphine, that indicates microbes may inhabit Earth’s inhospitable neighbour, a tantalizing sign of potential life beyond Earth.  This could be indicative of the presence of alien life on a planet that has always been described as inhospitable.



Don’t get carried by the word ‘neighbour’ – Venus is the closest planet to Earth (it's also the most similar in size). But its proximity to our planet depends on the orbits of both. The two planets travel in ellipses around the sun, and so the distance between them is constantly shifting. At its farthest, Venus lies 162 million miles (261 million kilometers) away, according to NASA. Venus takes 224.7 Earth days to travel around the sun. It makes its closest approach to Earth about once every 584 days, when the planets catch up to one another. On average, it is 25 million miles (40 million km) away at this point, though it can reach as close as 24 million miles (38 million km).

Most astronomers feel that it would be impossible for life to exist on Venus as it  is a very hostile place. It is a very dry planet with no evidence of water, its surface temperature is hot enough to melt lead, and its atmosphere is so thick that the air pressure on its surface is over 90 times that on Earth. Even the spacecraft which have landed on Venus only survived for about an hour before being crushed and melted. There are however, a few scientists who think that it is possible for life to exist in the clouds of Venus. 

Tyazhely Sputnik, also known by its development name as Venera 1VA No.1,  and in the West as Sputnik 7, was a Soviet spacecraft, which was intended to be the first spacecraft to explore Venus. Due to a problem with its upper stage it failed to leave low Earth orbit. In order to avoid acknowledging the failure, the Soviet government instead announced that the entire spacecraft, including the upper stage, was a test of a "Heavy Satellite" which would serve as a launch platform for future missions.  Tyazhely Sputnik was launched at 01:18:03 UTC on 4 Feb 1961, atop a Molniya 8K78 carrier rocket flying from Site 1/5 at the Baikonur Cosmodrome. When the upper stage ignited, cavitation in the liquid oxygen flowing through the oxidiser pump caused the pump to fail, resulting in an engine failure eight-tenths of a second after ignition. It reentered the atmosphere over Siberia on 26 Feb 1961.

After that mission,  several landers from the former Soviet Union have landed on Venus. They were only able to send  information for a short time because the extremely high temperature and pressure on the surface of Venus melted and crushed the landers. On Dec 15, 1970 an unmanned Soviet spacecraft, Venera 7, became the first spacecraft to land on another planet. It measured the temperature of the atmosphere on Venus. In 1972, Venera 8 gathered atmospheric and surface data for 50 minutes after landing. In  1975, Venera 9 landed on the surface of Venus. It took the first close-up photograph of the planet's surface. Three days later Venera 10 landed on Venus. Venera 10 took photographs of its surface and studied its rocks.

Phosphine is the compound with the chemical formula PH3, classed as a pnictogen hydride. It is a colorless, flammable, very toxic gas. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like garlic or rotting fish, due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present, PH3 is spontaneously flammable in air (pyrophoric), burning with a luminous flame.

Venus is one of the four terrestrial planets in the Solar System, meaning that it is a rocky body like Earth. It is similar to Earth in size and mass, and is often described as Earth's "sister" or "twin". The diameter of Venus is 12,103.6 km (7,520.8 mi)—only 638.4 km (396.7 mi) less than Earth's—and its mass is 81.5% of Earth's. Conditions on the Venusian surface differ radically from those on Earth because its dense atmosphere is 96.5% carbon dioxide, with most of the remaining 3.5% being nitrogen.

Venus is the second planet from the Sun. It is named after the Roman goddess of love and beauty. As the second-brightest natural object in the night sky after the Moon, Venus can cast shadows.   Venus lies within Earth's orbit, and so never appears to venture far from the Sun, either setting in the west just after dusk or rising in the east a bit before dawn. Venus orbits the Sun every 224.7 Earth days.  With a rotation period of 243 Earth days, it takes longer to rotate about its axis than any other planet in the Solar System and does so in the opposite direction to all but Uranus (meaning the Sun rises in the west and sets in the east).  Venus does not have any moons, a distinction it shares only with Mercury among planets in the Solar System.

PS 1 :  Philippe Gengembre (1764–1838), a student of Lavoisier, first obtained phosphine in 1783 by heating white phosphorus in an aqueous solution of potash (potassium carbonate).  Perhaps because of its strong association with elemental phosphorus, phosphine was once regarded as a gaseous form of the element, but Lavoisier (1789) recognised it as a combination of phosphorus with hydrogen and described it as phosphure d'hydrogène (phosphide of hydrogen).

PS 2 : the woman at the start -  Venus Williams (Venus Ebony Starr Williams) is the famous sister of Serena Williams and together they have dominated Professional tennis.    A former world No. 1 in both singles and doubles,  Venus Williams is generally regarded as one of the all-time greats of women's tennis and, along with younger sister Serena Williams, is credited with ushering in a new era of power and athleticism on the women's professional tennis tour.

PS 3:   Nightflight to Venus is the third studio album by Euro-Caribbean group Boney M., and was released in July 1978. The album became a major success in continental Europe, Scandinavia, and Canada, topping most of the album charts during the second half of 1978 and also became their first UK number one album.   Nightflight to Venus includes their worldwide hits "Rivers of Babylon" and "Brown Girl in the Ring", a double A-sided single that topped the UK singles chart and has sold over 2 million copies there.

Interesting ! 

With regards – S. Sampathkumar
15.09.2020.

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