The Venus Express plunge details reveal an exciting space mission that lasted eight years before it falls into the planet’s atmosphere. However, there’s something more to this plunge that will help scientists.
After eight years in orbit, the European Space Agency’s (ESA) Venus Express has completed routine science observations with a suite of seven instruments. The spacecraft has provided a comprehensive study of the ionosphere, atmosphere, and surface of the planet.
Venus Express was launched on a Soyuz-Fregat from the Russian Baikonur Cosmodrome in Kazakhstan on November 9, 2005, and arrived at Venus on April 11, 2006.
It has been orbiting Venus in an elliptical 24-hour loop that takes it from a distant 41,000 miles (66,000 kilometers) over the south pole — affording incredible global views — to an altitude of around 155 miles (250km) above the surface at the north pole, close to the top of the planet’s atmosphere.
“Venus Express has taught us just how variable the planet is on all timescales and, furthermore, has given us clues as to how it might have changed since its formation 4.6 billion years ago,” said Hakan Svedhem from ESA.
“This information is helping us decipher how Earth and Venus came to lead such dramatically different lives, but we’ve also noticed that there are some fundamental similarities.”
Just like Earth, Venus is losing parts of its upper atmosphere to space, and Venus Express measured twice as many hydrogen atoms escaping out of the atmosphere than oxygen. Because water is made of two hydrogen atoms and one oxygen atom, the observed escape indicates that water is being broken up in the atmosphere.
Today, the total amount of water on Earth is 100,000 times that on Venus. But because the two planets are about the same size and formed at the same time, both may have had similar amounts of the precious liquid in their early years.
Meanwhile, the spacecraft’s cameras have tracked thousands of features in the cloud tops some 40 miles above the planet’s surface, including an enormous swirling vortex at the planet’s south pole that shares similarities with hurricanes on Earth. The spacecraft also recorded bursts of lightning — identified by their electromagnetic signature — generated in clouds of sulphuric acid.
The Venus Express plunge comes after studies of the planet’s “super-rotating” atmosphere — it whips around the planet in just 4 Earth days, much faster than the 243 days the planet takes to complete one rotation about its axis — also turned up some intriguing surprises. In one study, average wind speeds were found to have increased from roughly 190 mph to 250 mph over a period of six Earth years.