Not sure where to ask or how to bring this to Google's attention, but it would appear Google Mars no longer works. Tried different browsers and the issue appears to be JS errors:
"This document requires 'TrustedHTML' assignment."
"Note that 'unsafe-inline' is ignored if either a hash or nonce value is present in the source list."
And so on. Is this a known issue? Apologies if this is not the right place to raise this issue but knowing google devs hang around I thought it might speed up a fix.