Context: Recently, an announcement by an international team of astronomers 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.
Key Points

• A team of experts used telescopes in Hawaii and Chile’s Atacama Desert to observe Venus’ upper cloud deck, around 60 km from the surface.
• They detected traces of phosphine.
• The latest finding is a fresh insight into conditions on planet Venus.
• Conditions on Venus are often described as hellish with daytime temperatures hot enough to melt lead and an atmosphere comprised almost entirely of carbon dioxide.
• However, the team has stressed that the presence of phosphine alone did not prove the presence of life on Venus.

About Phosphine gas

• Phosphine is a chemical that belongs to the group of organophosphorus compounds.
• It is a colourless and highly poisonous gas.
• Phosphine gas is associated with living organisms.
• It is a flammable gas that on Earth occurs from the breakdown of organic matter.
• It is released by microbes in oxygen-starved environments, such as lake sediments and animals’ innards.

About Planet Venus

• Venus is the second planet from the Sun and the third brightest object in Earth’s sky after the Sun and Moon.
• It is sometimes referred to as the sister planet to Earth, because their size and mass are so similar.
• Venus is also the closest planet to Earth.
• The surface of Venus is hidden by an opaque layer of clouds which are formed from sulphuric acid.
• The planet is named for Venus, the Roman goddess of love and beauty and is the second largest terrestrial planet. Venus is the only planet in the Solar System to be named after a female figure.
• Venus is sometimes referred to as the “morning star” and “evening star”.
• It takes 243 Earth-days to complete one rotation.

Conditions on Venus

• For 2 billion years, Venus was temperate and harboured an ocean.
• At present, a dense carbon dioxide atmosphere blankets a near-waterless surface where temperatures top 450 degrees C.
• The clouds in the sky are hardly inviting, containing droplets of 90% sulphuric acid.
• The conditions on Venus are so deeply unpleasant that many scientists believe the planet is dead.
• Rather than coming from floating Venusians, they suspect phosphine arises from more mundane processes.
• The discovery raises the possibility that life gained a foothold on Venus and remnants floated on as the planet suffered an out of control global warming that made the planet hellish.
• Venus is the hottest planet in the solar system with an average surface temperature of 462°C (863°F).
• Venus is so close and of such similar size to Earth that some experts believe it serves as a warning of the dangers of an out of control climate change.
• Venus doesn’t tilt on its axis which means there are no seasons either. 
• The atmospheric pressure of Venus is 92 times stronger than Earth’s.
• Venus has a very weak magnetic field. One possible reason for this is that Venus has no solid inner core, or that its core is not coolin.

Additional Information
Missions to venus

• More than 40 spacecraft have explored Venus so far. The 90s Magellan mission of NASA mapped the entire surface of Venus. The Japanese satellite Akatsuki is currently orbiting Venus to study its atmosphere.
• Missions to Venus have been planned by NASA and ISRO. While NASA’s mission named DAVINCI (Atmospheric probe) is slated for launch in 2021, ISRO is looking for the launch of the Shukrayaan-1 (orbiter and atmospheric balloon) in 2023.