The age of the earth is so much older than we initially could have believed, that sometimes the numbers don’t even seem real.
And with all of the misinformation out there – people who want to believe biblical accounts of time, etc – we can easily forget just how long this planet has existed.
If you’re curious just how many orbits she’s done around the Sun, we’ve got you covered.
Right now, while you’re sitting there reading this article, Earth is moving at 67,000 mph in its current orbit around the sun. Seven other planets are doing the same (at various speeds) and they’ve all been doing it for billions of years.
Since the orbit of most planets hasn’t changed, it’s not all that hard to calculate exactly how many times they’ve run the same orbit – at least, not for people who are good at math.
Jupiter, Saturn, Uranus, and Neptune were born around 4.59 billion years ago. 4.5 billion years ago Mercury, Venus, Earth, and Mars joined the party.
For the first 100 million years a “dynamical instability” caused a gravitational tug-of-war between the larger planets that means their orbits were not settled yet.
Since they settled, though, they haven’t changed much at all.
“For 98% to 99% of the solar system’s lifetime, the planets’ orbits have been nice and stable. As a result, you can use the planets’ current orbital dynamics to make a pretty accurate guess at how many trips they have made around the sun.”
Earth, for example, takes about a year to orbit the sun. Since it has existed for 4.5 billion years, it makes sense that we have made around 4.5 billion trips around the solar system.
The other planets are a bit trickier, since their years are longer or shorter than Earth’s.
Mercury orbits the sun every 88 days, so it has made 18.7 solar orbits in it’s line time. Neptune, on the other end of the spectrum, has a 164.7 year orbit, so has managed just 27.9 million trips.
And get this – most of the planets will make at least double their current number of trips during their remaining lifetime.
That lifetime?
Well, astrophysicists believe Mercury, Venus, and Earth will be destroyed when the sun transitions into a red dwarf star in around 4.5 billion years.
If the outer planets survive that, their orbits will most likely be changed in the process.
If you think that’s impressive, check out this story about a “goldmine” of lithium that was found in the U.S. that could completely change the EV battery game.