In 1974, NASA’s Mariner 10 space probe visited the planet Venus. The famous photos of the time were reworked in 2020.

Mariner 10 flew less than 6,000 kilometers past Earth’s neighbor in early February 1974. Astronomers were surprised to see several visible details in the dense cloud cover. Based on these details, they were able to determine that cloud cover orbits the planet once every four days. That’s sixty times faster than the planet itself spins. Venus rotates on its axis at a speed of two meters per second. And the Earth? It has a rotational speed of 450 meters per second.

The recently re-edited photo reveals even more details. We owe it to the brand new photo editing techniques applied by scientists. Incidentally, we do not see a surface in the photo, because Venus has a dense cloud cover. The clouds in the photo are 60 kilometers above the surface of the planet. They are made up of sulfuric acid particles. That – combined with a towering atmospheric pressure of over 90 bar and surface temperatures of over 400 degrees Celsius – makes Venus a thoroughly unpleasant vacation destination.

In this Space Photo of the Week you can see clouds with a red tint. That’s because there’s a mysterious material hidden in those clouds that absorbs blue light. Astronomers still don’t know exactly what material it is. Thus, Venus continues to keep secrets from us.

While Venus is an unlivable world today, it was different in the past. Scientists suspect that Venus was a habitable planet for billions of consecutive years, so organisms may have once crawled across the surface of the second planet in the solar system. We may never know, because Venus’ surface has been weathered by large-scale volcanic eruptions over the past few million years. Any trace of life has therefore probably already disappeared. Fun fact: without Jupiter, Venus would be today possibly a habitable planet.

Over the past few decades, space telescopes and satellites have captured beautiful images of nebulae, galaxies, stellar nurseries, and planets. Every weekend, we retrieve one or more impressive space photos from the archives. Enjoy all the photos? Check them on this page.