Since the start of the Space Age, we’ve learned a lot about the other planets of the solar system. But perhaps we’ve learned the most about Venus. That’s a bit of a surprise when you consider that Venus passes closer to Earth than any other planet.

Venus is the brilliant “morning star.” It lines up close to the crescent Moon before dawn the next couple of days.

Venus looks so bright in part because it’s blanketed by clouds that hide the surface. And that’s the main reason we’ve had so much to learn about the planet.

Without any landmarks to go by, astronomers couldn’t even tell the length of the planet’s day. They didn’t figure it out until the early 1960s. They used radio telescopes to bounce waves off the surface. The echoes revealed that a day on Venus lasts 243 Earth days.

For a long time, scientists thought the clouds were made of water vapor, just like the clouds on Earth. That led to speculation that Venus was warm and wet, with giant oceans and dense jungles. Instead, the clouds are made of sulfuric acid. And they hide a surface that’s hot enough to melt lead, with not a drop of water.

Today, planetary scientists are still learning about Venus. It appears to be volcanically active, for example – perhaps one of the most active worlds in the solar system. So, many more surprises could lurk below the clouds of our brilliant neighbor.

Script by Damond Benningfield