Long story short, Mars and the band are now cosmically linked forever because NASA has named an iconic rock on the planet's surface ... "Rolling Stones Rock."
As Downey Jr. enthusiastically explained ... NASA's successful landing of the InSight spacecraft last year on Mars sent a golf ball-sized rock rolling a few feet across the surface -- and the rocket scientists came up with a (sorta?) clever name for it.
It might just be one small stone for man, but it's one giant leap for Stones' kind.
BTW ... 76-year-old Jagger looked like he was ready for space exploration himself, showing no signs of slowing after the heart valve procedure earlier this year, which delayed the tour.
After the show, photogs got this shot of the frontman with a device hanging next to his neck -- and while there's a rumor it's there to monitor his heart ... that just ain't so.
A rep for the band tells us it's simply Mick's in-ear monitors which he's been wearing during concerts for the last, oh ... 60 or so years.