When you stand on the Earth’s surface, it’s easy to forget that our planet is orbiting the sun at over 67,000 mph (107,800 km/h). And it’s even easier to forget that there are seven other planets orbiting our own star at the same crazy speed, or that all eight have been orbiting the solar system continuously for billions of years.

But what will really blow your mind might be learning how many times each planet orbits the Sun. This may seem like a complicated calculation, but since the orbits of planets have remained largely unchanged for most of their existence, all it takes is a little basic math.

The Solar System was born about 4.6 billion years ago, when the Sun began to form from the dust cloud left over from earlier star explosions. Approximately 4.59 billion years ago, the giant planets (Jupiter, Saturn, Uranus and Neptune) were born. About 4.5 billion years ago, smaller rocky planets such as Mercury, Venus, Earth and Mars formed, according to The Planetary Society.

However, when the planets were born, their orbits around the Sun were not like today (especially the orbits of the giant planets). For about 100 million years after the formation of the first planets, there was a “dynamic instability” between them that caused a gravitational tug of war between these massive bodies, resulting in the formation of the remaining exoplanetary material of the outer solar system and even some new protoplanets. It will be ejected from the solar system, an astronomer and planetary systems expert at the Bordeaux Astrophysics Laboratory in France told Live Science in an email. Shawn Raymond

However, once all the planets emerged and were done jostling to find their positions, they settled into consistent, stable orbits that haven’t changed much since.

“The planets’ orbits were nice and stable for 98 percent to 99 percent of life in the solar system,” Raymond said. As a result, he added, using the current orbital dynamics of the planets, you can predict quite accurately how many orbits they take around the sun.

Take the Earth for example. It takes our planet a year to orbit the sun and has been orbiting it for 4.5 billion years, meaning it has made approximately 4.5 billion trips around the solar system. However, the total number of orbits of other planets varies greatly because their years are shorter or longer than Earth’s.

Mercury, the closest planet to the Sun, takes only 88 days (or about 0.24 years based on a 365.25-day year) to orbit the Sun once. Thus, it has made approximately 18.7 billion revolutions around the Sun in the last 4.5 billion years. But Neptune, the farthest planet from the Sun, takes about 60,190 days (or 164.7 years) to complete one orbit; This means that it has made only 27.9 million trips around the Sun in its 4.59 billion years of existence. This means that Mercury orbits the Sun approximately 18.7 billion times faster than Neptune.

Here is the complete list of planets, their year lengths and total number of rotations around the Sun:

These numbers sound impressive (and they are), but most planets could potentially double the number of orbits in the remaining time.

After about 4.5 billion years, the Sun will expand outward to reach Earth’s orbit and become a red dwarf star, destroying Mercury, Venus, and Earth. Other planets may survive for a while longer if they don’t burn up, but their orbits are likely to change significantly.