Why there are so few images of Venus' surface

In the search for extraterrestrial life within the Earth's solar system, it's Venus, not Mars, that's emerging as the leading candidate.

On Monday, scientists revealed they detected traces of phosphine, a toxic gas that is produced by microorganisms on Earth, high in Venus' atmosphere. To be clear, there's only evidence of phosphine, not life itself. Theoretically, the gas could be forged by a chemical process scientists haven't seen before, but Clara Sousa-Silva, a molecular astrophysicist at the Massachusetts Institute of Technology and one of the study's authors, said life — likely microbes in the clouds — is the "most plausible explanation" for now.

On its face, the news is pretty surprising given that, as The Atlantic describes, Venus is a "planet-sized furnace" where surface temperatures hover around 860 degrees. There are very few photos of the planet's surface, save for a few taken in the 1980s by probes deployed by the Soviet Union. The images show a barren, rocky wasteland beneath an apocalyptic sky that has a yellow-ish, foggy tinge and certainly does not scream "life!" at first glance. Indeed, the probes that landed on Venus in the '80s only lasted for up to two hours. There have been no surface-landing missions to Earth's neighbor since 1985.

But there weren't always extreme conditions on the second planet from the Sun, The Atlantic notes. For billions of years, Venus was covered in oceans that would have been habitable, so scientists have held on to the idea that life might exist in the atmosphere, perhaps "the last remnant of a wrecked biosphere." Now, there's a possibility that's the case. Read more at The Atlantic and see images of Venus' surface here.