The planet Uranus is the third largest in our solar system and is so large that you could fit 63 Earth’s inside of it. That’s one big planet! Uranus has another distinguishing characteristic…it is the only planet that is tilted sideways. It has a 93 degree tilt, which is severely different from Earth’s 23 degrees and Jupiter’s 3 degrees. This is highly unusual, and astronomers have long debated how this could have happened. The popular conventional wisdom was that a massive object, much larger than Earth, impacted Uranus billions of years ago, knocking it into the peculiar spin it exhibits today. The latest studies are showing much different findings, however.
The reason for doubting the conventional wisdom was that if a collision of that sort occurred, Uranus would have retrograde motion, the opposite of what it has long been observed to do. The supposed collision would have taken place in the early days of our solar system, when Uranus was still surrounded by a disc of dust and gas that over billions of years would eventually become its five moons. If this were true, scientists surmised, the moons would take the same tilt as the planet, which they do. This lent credence to the theory, but Uranus does not have retrograde motion, stoking the fascination with how this solar system atrocity could have come to be.
The latest studies found that multiple collisions by much smaller objects is a much more likely explanation for the status quo. So, it seems that the early solar system was a much more
violent place than originally imagined.
What does it mean for Earth? It means that the results of small objects impacting the Earth can have unbelievable repercussions. Most apocalyptic theories revolving around objects from space striking the Earth do not take into
account the idea of something actually changing the tilt of the Earth. In a time when comets like Elenin invoke disaster-event predictions, this is an interesting finding and shows us the precarious nature of space and Earth’s place in it.