An old, abandoned spacecraft has just send some strange data from the atmosphere of Venus. The European Space Agency's (ESA) Venus Express spacecraft spent eight years gathering information on Venus before dropping down to the surface and out of range back in November 2014. But now we lastly have the remaining batch of data it transferred back to Earth before going of the grid, and there are some big disclosures in all those recordings.
Image Credit: ESA/C. Carreau
So it turns out, the polar atmosphere of Venus is a way too colder and a lot less more dense than we previously thought, and these areas are ruled by strong atmospheric waves that have never been recorded on Venus before. Maddie Stone from Gizmodo reports that the Venus Express spacecraft spotted polar areas of Venus to have an average temperature of -157 degrees Celsius, which is way colder than any area on Earth, and around 70 degrees lower than was previously thought.
This is quite astonishing, considering Venus's location as the hottest planet in the Solar System in general.
Not only Venus is a lot closer to the Sun than us, it also has a heavy, dense cloud coating that traps heat. Nevertheless, Venus Express also discovered that the planet's atmosphere was about 22 to 40 percent less dense than projected at the polar areas. Lead researcher, Ingo Müller-Wodarg, from the Imperial College London, said:
"The existing model paints an overly simplistic picture of Venus's upper atmosphere. These lower densities could be at least partly due to Venus' polar vortices, which are strong wind systems sitting near the planet's poles. Atmospheric winds may be making the density structure both more complicated and more interesting!"
That’s not it yet, because there is more: the Venus Express found these same areas to be controlled by strong atmospheric waves, which act like ripples in a pond, but they travel vertically instead of horizontally.
These waves are believed to be crucial in manipulating a planet's atmosphere, counting the one we have here on Planet Earth, but these waves have never been recorded or measured on Venus before.
These discoveries became even more exciting when researchers realize that the observation were made by instruments that weren't planned for in-situ atmosphere observations: it was only after the launch of the Venus Express that researchers recognized they could use accelerometer measurements to measure atmosphere density.
Håkan Svedhem, a scientist for both the ExoMars 2016 and Venus Express missions, said:
"For Mars, the aerobraking phase would last longer than on Venus, for about a year, so we'd get a full dataset of Mars' atmospheric densities and how they vary with season and distance from the Sun.This information isn't just relevant to scientists; it's crucial for engineering purposes as well."