• The European Space Agency (ESA) announced the selection of EnVision as its newest medium-class science mission. EnVision will make detailed observations of Venus to understand its history and especially understand the connections between the atmosphere and geologic processes. 

• NASA is a partner with ESA on the EnVision mission.

• The new mission to Venus comes at a time when NASA has just announced their upcoming DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) and VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) missions. 

• Working in concert, the trio of new spacecraft will provide the most comprehensive study of Venus ever. 

Highlights of this mission:

• The mission was selected by ESA’s Science Programme Committee on June 10 as the fifth Medium-class mission in the Agency’s Cosmic Vision plan, targeting a launch in the early 2030s.

• It will provide a holistic view of the planet from its inner core to upper atmosphere to determine how and why Venus and Earth evolved so differently.

• A key question in planetary science is why, despite being roughly the same size and composition, our next-door neighbour in the inner Solar System experienced such a dramatic climate change. Instead of being a habitable world like Earth, it has a toxic atmosphere and is enshrouded with thick sulphuric acid-rich clouds. 

• EnVision’s innovative instrument package will tackle this big question. The new observations can also tell us about the evolution of Venus.

• As a key partner in the mission, NASA provides the Synthetic Aperture Radar, called VenSAR, to make high resolution measurements of the planet’s surface features.

• EnVision follows on from ESA’s highly successful Venus Express (2005-2014) that focused primarily on atmospheric research, but which also made dramatic discoveries that pointed to possible volcanic hotspots on the planet’s surface. JAXA’s Akatsuki spacecraft has also been studying the atmosphere since 2015. 

• With significantly higher resolution than that of NASA’s Magellan mission, which captured images of Venus in the early 1990s, VenSAR will improve our understanding of the planet’s surface features. 

Venus is often called “Earth’s twin”

• Venus is the second planet from the Sun and is Earth’s closest planetary neighbour. It’s one of the four inner, terrestrial (or rocky) planets, and it’s often called “Earth’s twin” because it’s similar in size and density. 

• These are not identical twins, however – there are radical differences between the two worlds.

• Venus has a thick, toxic atmosphere filled with carbon dioxide and it’s perpetually shrouded in thick, yellowish clouds of 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. 

• Surface temperatures on Venus are about 900 degrees Fahrenheit (475 degrees Celsius) – hot enough to melt lead. 

• The surface is a rusty color and it’s peppered with intensely crunched mountains and thousands of large volcanoes.

• Venus rotates on its axis backward, compared to most of the other planets in the solar system. This means that, on Venus, the Sun rises in the west and sets in the east, opposite to what we experience on Earth. 

• Venus rotates very slowly on its axis – one day on Venus lasts 243 Earth days. The planet orbits the Sun faster than Earth, however, so one year on Venus takes only about 225 Earth days, making a Venusian day longer than its year.

• 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 December 14, 1962. Since then, numerous spacecraft from the U.S. and other space agencies have explored Venus

Other upcoming Venus missions:

DAVINCI+ 

DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging) will measure the composition of Venus’ atmosphere to understand how it formed and evolved, as well as determine whether the planet ever had an ocean. The mission consists of a descent sphere that will plunge through the planet’s thick atmosphere, making precise measurements of noble gases and other elements to understand why Venus’ atmosphere is a runaway hothouse compared to the Earth’s.

In addition, DAVINCI+ will return the first high resolution pictures of the unique geological features on Venus known as “tesserae,” which may be comparable to Earth’s continents, suggesting that Venus has plate tectonics. 

This would be the first US-led mission to Venus’ atmosphere since 1978, and the results from DAVINCI+ could reshape our understanding of terrestrial planet formation in our solar system and beyond. 

VERITAS 

VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) will map Venus’ surface to determine the planet’s geologic history and understand why it developed so differently than Earth. Orbiting Venus with a synthetic aperture radar, VERITAS will chart surface elevations over nearly the entire planet to create 3D reconstructions of topography and confirm whether processes such as plate tectonics and volcanism are still active on Venus.

VERITAS also will map infrared emissions from Venus’ surface to map its rock type, which is largely unknown, and determine whether active volcanoes are releasing water vapour into the atmosphere. 

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