EnVision MISSION

The mission

• EnVision is an ESA led mission with contributions from NASA. It is likely to be launched sometime in the 2030s.
• Once launched on an Ariane 6 rocket, the spacecraft will take about 15 months to reach Venus.
• The spacecraft will carry a range of instruments to study the planet’s atmosphere and surface, monitor trace gases in the atmosphere and analyse its surface composition.
• A radar provided by NASA will help to image and map the surface.

Questions that the Mission seeks to get answers to

• How Earth and Venus evolved so differently from each other considering that they are roughly of the same size and composition.
• Is Venus still geologically active?
• Could it have once hosted an ocean and even sustained life?
• What lessons can be learned about the evolution of terrestrial planets in general, as we discover more Earth-like exoplanets?

About Venus

• For those on Earth, Venus is the second-brightest object in the sky after the moon.
• It appears bright because of its thick cloud cover that reflects and scatters light.
• Venus, which is the second closest planet to the Sun, is called the Earth’s twin because of their similar sizes.
• The planet’s thick atmosphere traps heat and is the reason that it is the hottest planet in the solar system, despite coming after Mercury, the closest planet to the Sun.
• Surface temperatures on Venus can go up to 471 degrees Celsius, which is hot enough to melt lead.
• Further, Venus moves forward on its orbit around the Sun but spins backwards around its axis slowly.
• This means on Venus the Sun rises in the west and sets in the East.
• One day on Venus is equivalent to 243 Earth days because of its backward spinning, opposite to that of the Earth’s and most other planets.
• Venus also does not have a moon and no rings.

Previous Missions

• Because of the planet’s harsh environment, no humans have visited it and even the spacecraft that have been sent to the planet have not survived for a very long time.
• So far, spacecraft from several nations have visited the planet.
• The first such spacecraft was the Soviet Union’s Venera series (the spacecraft, however, could not survive for long because of the planet’s harsh conditions), followed by NASA’s Magellan Mission that studied Venus from 1990-1994.
• As of now, Japan’s Akatsuki mission is studying the planet from Orbit.

Future Missions

• DAVINCI+ and VERITAS are part of NASA’s Discovery Program, which began in 1992.
• The two selections are a part of the ninth Discovery Program and were made from proposals submitted in 2019.

DAVINCI+

• DAVINCI+ is short for ‘Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging’ and is the first US-led mission to the planet’s atmosphere since 1978.
• It will try to understand Venus’ composition to see how the planet formed and evolved.
• It will pass through the planet’s thick atmosphere and make observations and take measurements of noble gases and other elements.
• It will also try to return the first high resolution photographs of a geological feature that is unique to Venus.
• This feature, which is called “tesserae” may be comparable to Earth’s continents.
• The presence of tesseraes may suggest that Venus has tectonic plates like Earth.

Veritas

• VERITAS is short for ‘Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy’ .
• It will map the planet’s surface to determine its geologic history and understand the reasons why it developed so differently from Earth.

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