The Planet We Forgot About: Why Venus Needs More Exploration
It’s been almost 40 years since the last spacecraft landed on Venus. But why have been ignoring our Earth-sized neighbor for so long?
True color image of Venus; Source: Wikipedia
There are three places in the Solar System that have received all the attention of scientists and engineers across the globe: Earth’s orbit, the Moon, and Mars. All three have a deep interconnectedness that lies in our very nature: Earth’s orbit is closest to home, the Moon protects us every night and controls the tides, and Mars has always been the curious red neighbor with seasons and Martian aliens who — at least in literature — go to war with Earthlings.
But while Mars is all the focus for crewed missions and extraterrestrial cities, it’s also fairly far away; on average 225 million km.
However, 40 million km from home lies another world — one that is almost as big as Earth with a thick atmosphere; a world closer to the Sun that interacts with the solar wind and thus offers the planet protection from toxic interstellar radiation.
It would almost be heaven for Earthlings… if only… if only—
If only the planet hadn’t an atmosphere composed primarily of carbon dioxide with an average surface temperature of 464°C and a surface pressure equal to being 1’000m underwater — conditions so extreme that even the Soviet landers that touched down decades ago could only operate for a few hours before melting in the sheer heat.
If you were in the shoes of those scientists trying to figure out where to send a mission, surely you’d prefer a world colder than Antarctica over a hell hotter than anything we can imagine.
But despite Venus’ hostility, it’s an intriguing planet for exploration. The fact that the Soviet Union launched so many missions to the planet during the early days of space exploration is proof enough that it’s worth visiting.
Sometimes, two stars rise in the morning: one wakes up a bit earlier than the Sun, sometimes even casting a light on water surfaces when skies are dark enough. In other times, the fainter star disappears in the morning and instead shines in the evening skies, like a guardian over us humans.
Venus as the “Morning Star” or “Evening Star” has long been an element in many cultures across the globe. It’s the brightest object in the sky after the Sun and the Moon, which means that Venus plays a crucial role in cultures across the world.
As scientists learned more about our neighboring planet, including that it has a thick atmosphere with a global cloudcover, the public speculated about conditions on Venus just as they depicted Mars: an inhabited world covered in rich flora and fauna. In both cases, disappointment was big when Venus turned out to be a dead planet whose conditions should be avoided by any forms of life.
And then the age of space exploration ensued.
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| UV light reveals intricate patterns in Venus' clouds; Source: Wikipedia |
Why explore Venus? One of the answers should be that observing Venus beyond its shroud of clouds from Earth is practically impossible. These clouds never allow for clear skies, and even observations in the infrared or ultraviolet don’t reveal much more.
The first Venus flyby happened in 1962, when the American Mariner 2 became the first spacecraft to perform a successful flyby of another planet. Five years later arrived the Soviet Venera 4.
Venera 4 was the first spacecraft to analyze another planet’s atmosphere; it found that the Venusian atmosphere was unlike anything life could hope for, containing mainly carbon dioxide and nitrogen. It also found that the magnetic field is 3000 times weaker than Earth’s — Venus’ primary source for its magnetosphere comes from interactions with the ionosphere and the solar wind.
Venera 4 also had an ambitious plan: land on the surface of Venus. Sadly, the lander never made it to the surface, it impacted in the Eisila region.
Two years after the successful Venera 4 mission, in the year of the epic Moon landing, Venera 5 and 6 arrived at Venus, just a few days apart, and probes descended into the Venusian atmosphere, providing a wealth of data for 50 minutes before the sheer pressure of the atmosphere crushed them.
Knowledge gathered by Venera 4 helped improve the mission of the twin spacecraft in that their parachutes were made smaller so that they would operate longer in Venus’ atmosphere. It was a success and offered more precise data on the atmospheric composition, further aiding missions to come.
Venera 7 profited from the collected data and helped it perform a soft landing on Venus’ surface, the first yet to do so. Two years later, in 1972, Venera 8 made another successful landing and, being an improved design, beamed back a lot of data back to Earth.
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| Photos taken by Venera 9 and 10; Source: Pinterest |
The 1975 Venera 9 would become the first spacecraft to transmit photos of the Venusian surface back to Earth. These photos may have been very primitive and in black-and-white, but that was a historic milestone that proved: Venus can be explored. All it takes is learning from previous missions and a little bit of craze.
The Soviet Union launched nine more spacecraft to Venus, the last in 1984 when Vega 2 deployed a lander and balloons that explored the Venusian atmosphere. Venera 13, launched in 1981, provided the first sound recordings from the alien world.
Meanwhile, NASA initially only launched spacecraft to Venus for flybys. Then, in 1978, the twin Pioneer Venus orbited the planet of hell for 15 years. The Pioneer Venus Multiprobe also descended a number of probes into the atmosphere, which provided more details on the temperature and environment.
In 1989, the United States launched the Magellan orbiter, which had been in Venus’ orbit for four years. Magellan mapped the surface of Venus, its topography, and gravity field.
In 2005, the ESA launched its first mission to our neighbor, the Venus Express. The orbiter found a thin layer of ozone in the atmosphere, a critical component of Earth’s atmosphere that protects us from toxic interstellar radiation.
But Venus Express also delivered valuable data that will aid future observations of habitability in exoplanetary systems. Yes! Venus Express was used to observe signs of life on Earth from Venusian orbit. From there, Earth was just a dot in the images and any signs life leaves behind are used for studies of habitability on exoplanets.
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| Model of the Akatsuki orbiter; Source: Wikipedia |
Venus is looking empty at the moment. Only one active mission remains — the Japanese Akatsuki orbiter.
But going back to Venus is an urgent manner — why?
Because Venus is the Earth’s twin, yet also its solar opposite.
Scientists believe that Venus, just like Mars, was once covered with oceans of water and may have even born life. So why is Earth the only planet that is still sustainable to life? What happened on Venus that it suffered a runaway greenhouse effect that effectively rendered the planet uninhabitable?
With the threats of climate change on our beloved Earth, the present of Venus could be a dark prediction of what lies ahead of us. And because Venus is so similar yet different, it could tell us a lot about how life emerges.
In which nooks and crannies could life develop? Could it be in the clouds of Venus? Has Venus ever hosted life? If not, does this mean the Rare Earth Hypothesis is correct?
There’s so much to learn.
We just have to go out there.
So which missions are planning to head to Venus?
One of them is NASA’s DAVINCI, short for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging. The goal is to study Venus and finally answer the question: has Venus ever been habitable? An atmospheric probe will descend through the Venusian clouds, which will also reveal a lot about the planet’s meteorology.
Planned to launch in the late 2020s, the glory of the exploration of Venus is set to return, all reminiscent of the days when Venera probes were launched annually.
Much sooner could be the launch of MIT/Rocket Lab’s Venus Life Finder, proposed to launch next year in one of Rocket Lab’s Electron rockets. It’s going to be the first time that a private company launches a mission to Venus.
The aim of the Venus Life Finder is as straight-forward as its name suggests: descend a probe into the atmosphere to search for compounds of life.
Among the missions planning to map the Venusian surface are NASA’s VERITAS, launching in 2031, and the ESA’s EnVision, launching in 2032.
But the Russians also want to return to Venus with the Venera-D mission. As in the old days, the mission would consist of an orbiter and a lander. However, so far, the path for Venera-D has been troubling. The mission was initially planned to launch in 2013, but various delays pushed the project back. Now, the mission will launch no earlier than 2029.
Venus is calling. And space agencies across the world recognize that it’s high time we go back — after all, spacecraft have collected so much valuable data which will now define the future of exploration of Venus. For even though Venus is a world of inhospitability, it offers intrigue, as well as secrets to be uncovered.
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