Flat-Earthers are having one heck of a week. Not only is one of these deniers of terrestrial sphericalness about to embark on a most audacious experiment, but they've now come to the attention of none other than Elon Musk.

The Tesla and SpaceX chief has a bit of a vested interest in the shape of planets – given he wants to colonise them – and with all the hullaballoo over flat Earth conspiracy theories recently, Musk got a little philosophical on Twitter.

While pondering the exotic spectacle of the Martian sunset, the CEO wondered: given there's such a thing as the Flat Earth Society (yep), why doesn't the Red Planet have its own equivalent?

"Why is there no Flat Mars Society!?" he tweeted, probably just to amuse himself and his followers, and likely never expecting to find a serious response.

But that's exactly what he got, with the official Twitter account for the Flat Earth Society – don't worry, they're verified! – earnestly responding to the question.

According to whoever's handling tweets for the Flat Earth Society these days, there's a perfectly understandable explanation for why there's no Flat Mars Society, and it all comes down to science.

"Hi Elon, thanks for the question. Unlike the Earth, Mars has been observed to be round," the FES replied, "We hope you have a fantastic day!"

Of course, what's so confusing about this perfectly amicable response is that it kind of flies in the face of conventional flat-Earther logic, which suggests scientific observations of Earth's spherical shape are flawed or faked.

As California man Mike Hughes – who intends to launch himself on a rocket to prove Earth is flat as soon as he gets permission – explains, "John Glenn and Neil Armstrong are Freemasons… Once you understand that, you understand the roots of the deception."

That's the kind of conspiracy thinking that leads flat-Earthers to set up ambitious crowdfunding campaigns to ostensibly conduct their own 'real' scientific experiments.

For example, like when rapper and evident flat-Earther B.o.B ran a GoFundMe campaign to launch "one, if not multiple" satellites into space.

Astronauts had a lot of fun at B.o.B's expense, and now, given the publicity around Mike Hughes's imminent rocket launch, scientists are again appealing for a bit of reason here.

After all, we've already got decades of observational evidence telling us the Earth is a sphere – you know, just like Mars – so there's no need to build a dangerous (and potentially deadly) homemade rocket.

And if you don't believe that, then why haven't we ever seen a lunar eclipse like this?

In fact, on second thought, maybe let's not ask any more questions. We might end up getting another answer.