explained-reading-life-signature-on-venus

Context: The news about the discovery of phosphine gas in the atmosphere of Venus triggered global excitement about the possibility of the presence of lifeforms on the neighbouring planet. 

About the discovery

  • A team of scientists have reported traces of phosphine in a concentration of approximately 20 parts per billion.
  • Apart from being produced in industrial processes, phosphine is known to be made only by some species of bacteria that survive in the absence of oxygen. 
    • This has triggered the speculation about the presence of microbes in Venus.
  • The presence of phosphine is “unexplained” after an exhaustive study of all the possible other sources in Venus’s atmosphere, clouds, surface and subsurface, or from lightning, volcanic or meteorite delivery”.
  • However this was not a confirmation of the presence of life on Venus.

Venus

  • Venus is the second closest planet to the sun at a distance of about 67 million miles (108 million km).
  • Similar in size and structure to Earth, Venus has been called Earth's twin. 
  • One day on Venus lasts 243 Earth days because Venus spins backwards, with its sun rising in the west and setting in the east.
  • Venus has a thick, toxic atmosphere filled with carbon dioxide
  • It’s perpetually shrouded in thick, yellowish clouds of mostly sulfuric acid that trap heat, causing a runaway greenhouse effect. 
  • It’s the hottest planet in our solar system, even though Mercury is closer to the Sun. 
  • Venus has crushing air pressure at its surface – more than 90 times that of Earth – similar to the pressure you'd encounter a mile below the ocean on Earth.
  • Venus was the first planet to be explored by a spacecraft – NASA’s Mariner 2 successfully flew by and scanned the cloud-covered world on Dec. 14, 1962.
  • Venus has no moons and no rings.
  • Venus' solid surface is a volcanic landscape covered with extensive plains featuring high volcanic mountains and vast ridged plateaus.
  • Many scientists believe water once existed on the surface. Future Venus explorers will search for evidence of an ancient ocean.

 

About Phosphine

  • Phosphine is a colorless, flammable, and explosive gas at ambient temperature that has the odor of garlic or decaying fish. 
  • It is slightly soluble in water. 
  • Although industrially produced, Phosphine is also made naturally by some species of anaerobic bacteria—organisms that live in the oxygen-starved environments of landfills, marshlands, and even animal guts.
  • Uses: Phosphine is used in semiconductor and plastics industries, in the production of a flame retardant, and as a pesticide in stored grain.
  • Effects on humans: Acute (short-term) inhalation exposure to phosphine may cause headaches, dizziness, fatigue, drowsiness
Image Source: Nasa