NASA Announces Two Missions To Venus, Here's What's Exciting About It

While so far Venus has remained largely꧃ unexplored, things are soon about to change.

Two ambitious NASA missions to Venus have recently received the green signal. They will launch between 2028-2030, as pe⛦r the latest announcement made by NASA’s solar system exploration programme.

This is an excitin♍g development as no mission has been sent to the planet since 1990.

Venus is a hostile world. Its atmosphere contains sulphuric acid🥀 and the surface temperatures is hot enough to melt lead. But it has not always been this way. It is thought Venus started out very similar to the Earth. So what happened?

While on Earth, carbon is mainly trapped♉ in rocks, on Venus it has escaped into the atmosphere – making it roughly 96 per cent carbon dioxide. This has led to a runaway greenhouse effect, pushing surface temperatures up to 750 kelvin (470 degree celsius or 900 degree Fahrenheit).

The planet’s history makes it an excellent place to study the greenhouse effect and to learn how 🐼to manage it on Earth. We can use m༒odels which plot the atmospheric extremes of Venus, and compare the results to what we see back home.

But, the extreme surface conditions are one of the reasons planetary exploration missions have avoided Venus. The high temperature means a very high pressure of 90 bars (equivalent to roughly one kilometre underwater) which is enough t💮o instantly crush most planetary landers. It might not come as a surprise, then, that missions to Venus haven’t always gone to plan.

Most of the exploration done so far was carried out by the then Soviet Union between the 1960s and the 1980s. There are some notable exceptions, such as Nasa’s Pioneer Venus mission ꦓin 1972 and the European Space Agency’s Venus Express mission in 2006.

The first landing happened in 1970, when the Soviet Union’s Venera 7 crashed due to the parachute melting. But it managed to transmit 20 minutes of data back to Earth💞. The first surface images wer🎉e taken by Venera 9, followed by Veneras 10, 13 and 14.

The descent mission

The first of the two selected Nasa missions will be known as Davinci+ (a shortening of Deep Atmosphere of Venus Investig💧ations of Noble Gases, Chemistry and Imaging). It includes a descent probe, meaning it will be dropped through the atmosphere, taking measurements as it goes. The descent has three stages with the first investigating the entire atmosphere.

The p🦄ro🦂be will be looking at the composition of the atmosphere in detail, providing information on each layer as it falls. We know sulphuric acid is confined to cloud layers at around 50km (30 miles) up, and we know that the atmosphere is 97 per cent carbon dioxide.

But studying trace elements can provide information on how the atmosphere ended up in this state. The second stage will be looking at lower altitudes to measure weather properties such as w🐓ind speed, temperature and pressure in detail.

The last stage take surface images in high resolution. While this is very common for Mars, it has always been a challenge on Venus. The thick cloud layer means visible light is reflected, so observing from Earth or from orbit isn’t practical. The intense♐ surface conditions also mean rovers are impr𝕴actical. One suggestion has been a balloon mission.

We have a low resolution image of the surface of Venus, thanks to Nasa’s Magellan missi🐼on in 1990, which mapped the surface using radar. The Davinci probe will take surface images using infrared light during its descent. These pictures will not only allow better planning for future missions but also ꦺhelp scientists investigate how the surface formed.

Mapping the surface

The second mission is called Veritas, short for Venus Emissivity, Radio science, InSAR, Topography and Spectroscopy. This will be a more standard planeta𒅌ry mission. The orbiter will carry two instruments on board 🌠to map the surface, complementing the detailed infrared observations from Davinci.

The♉ first of these is a camera that observes in a range of wavele🅘ngths. It can see through the Venusian clouds, to investigate atmospheric and ground composition.

This task is very difficult, as the surface temperature c♓auses the reflected light to have a very broad range of wavelengths. Veritas wi๊ll compensate for this using techniques often used to study the atmospheres of exoplanets.

The wavelength camera will also look for signs of water vapour. The Venus Express mission showed that the main elem﷽ents escaping the Venusian atmosphere are🐽 hydrogen and oxygen, so if there’s any water it will be in tiny amounts, or deep under the surface.

The second instrument is a radar anꦺd utilises a technique used extensively on Earth observation satellites. A very large active radio receiver – important for high resolution images – is simulated using radio pulses pointed at different angles in front of the spacecraft.

The high resolution rad🥃ar images will create a more detailed map to investigate the surface evolution of Venus, as well as determine if there is any tectonic or volcanic activity♌.

These missions could also add evidence to a theory that the Venusian surface completely melted and reformed 50💞0 million years ago. This came about to explain the lack of meteorite im🔴pacts on the surface, but so far no evidence has been found a volcanic lava layer which would result from such resurfacing.

It is exciting that Nasa hasꦯ turned its planetary mission view towards Venus. For any budding astronauts I’m afraid the chance of sending a human there any time soon is non-existent. But, the information that can be gained from Earth’s❀ largely forgotten sister will be of very high value for understanding our world.

(With inputs from PTI)