If you remember learning about the planets in school, you probably thought Venus was the closest one to Earth. But it turns out that’s not quite right. In fact, Mercury holds that title!
Mercury is the closest planet to Earth most of the time, despite being the innermost planet in our Solar System. According to astrophysicists, this has to do with how we define “closeness.” A team of researchers explained in a 2019 commentary that they analyzed the average distances between planets over thousands of years. Their results showed that, on average, Mercury is indeed nearer to Earth than Venus.
They ran a simulation tracking the eight planets for 10,000 years, and found that Mercury is the closest to all other planets, including the farthest one, Neptune. This discovery challenges a long-held assumption. The researchers pointed out that people often rely on a flawed understanding of planetary distances.
The reasoning behind this observation is fascinating. When planets orbit the Sun, the distance between them varies. The team coined the term “whirly-dirly corollary” to describe this phenomenon where the average distance decreases as one planet moves closer to the inner orbit. It sounds complicated but essentially means that when Mercury is at its nearest point in orbit to Earth, it beats Venus in proximity.
Historically, this misconception about Venus as Earth’s closest neighbor has been around for nearly two decades. The misunderstanding is so widespread that it has even made its way into popular science discussions and educational content.
As our understanding of the universe grows, so do the ways we explore and learn about it. Whether you’re a space enthusiast or just curious about astronomy, it’s exciting to see how new research reshapes our knowledge.
For more on the science behind this discovery, check out the full commentary in Physics Today.
