Thousands of weird green algae balls have washed up on an Australia beach in Sydney.

As with any weird phenomenon, the only explanation can be aliens. But in reality, they're created by living algae being shaped into spherical shapes by waves, Great Britain's The Telegraph reported.

However, such a thing is so rare that it's only been seen a handful of times.

How can they explain the thousands of them on one beach? Aliens. Definitely aliens.