For now, at least, the appearance on Bureau of Meteorology radar of a giant 'S' off the coast of Western Australian is unexplained.
There's no cloud, there's nothing to produce a rain echo, ...which we do see a lot, but not this particular shape," he said.
"They don't take on S shapes and things like that."
ABC News asked the Department of Defence if the 'S' has anything to do with them. No comment.
This isn't the first time bizarre looking things have shown up on BoM radar. Check out these giant discs from 2010. Here's just one:
If that catches your interest, check out this:
Australia's Bermuda Triangle? Or Is It Australia's Area 51?
Bizarre Discs Appear On Bureau Of Meteorology Over 3 States