Answer: Searching For Life On Earth

The primary mission of the European Space Agency’s Venus Express orbiter was, as the name strongly implies, to study Venus (specifically the atmosphere thereof). The mission duration was intended to be two years with extended measurements made of the Venetian atmosphere but, thanks to favorable conditions and multiple mission extensions, the craft managed to squeeze out nearly nine years of observations before it “deorbited” in early 2015.

While that might have been the primary mission, the secondary mission was one that might leave, at first glance, more than a few readers puzzled. The secondary mission of Venus Express was to find life on Earth.

Why find life on Earth when we already know life on Earth exists? While in orbit around Venus, the view Venus Express had of Earth was very similar to the view we, with other observation equipment like space telescopes and probes, have of distant Earth-like planets. The secondary mission of Venus Express wasn’t as much to prove that life exists on Earth but to prove that the technology we have and the techniques we’re using to find life on other planets would work on the only confirmed test subject we have: dear old Earth. By carefully observing Earth at such a distance and recording every bit of information that could be discerned from so far away with the spectrometers, cameras, and other equipment aboard Venus Express, we’re better able to apply what we know about observations of life-hospitable planets at a distance to our searches for life elsewhere in the universe.