Sorry, make that one and a bit Earth-mass instead.

Actually no, not that high in mass even.

- The mass of our Moon = 0.012 of the Earth’s.
(Source : Page 34, ‘Stars & planets’ Patrick Moore, Chancellor press, 1992.)

- The mass of Venus = 0.815 of Earth’s. (Page 30, ibid.)

So combining them results by my calculator anyhow in 0.827 or NOT even a single Earth mass! (one Earth mass here = 1.) Which of course isn’t even allowing for the likely factor that much of the material from a collision would be ejected from both worlds!

FWIW. Mars = 0.107 Earth masses (page 40, ibid) & Mercury = 0.055 (page 28, ibid) so combining those two rock dwarfs would again only get us to 0.162 where one earth mass = 1.

Combining Mars with Venus = 0.922 &
Combining Mercury with Venus = 0.87

Still leaving us without even one Earth mass. I’m very surprised by these figures and unsure if they’re actually correct but its what the calculator says &, yes, I’ve rechecked. Maybe my maths or methodology here is wrong, maybe I’m mistaken – & if I am please let me know – but, that’s what I’ve calculated here.

..would the Moon and Venus fuse – maybe at slower speeds into one double earth-mass

Arrghh! What was I thinking!?

The Moon is NOT an Earth mass natch. Sorry, make that one and a bit Earth-mass instead. Mea culpa.

Amazing what modern technology can do when you think about it.

The Moon and Venus make a pretty pair, don’t they?

Yes but I wouldn’t want them to physically meet!

It may be quite a spectacular collision but I think we could do without the likely swarm of red-hot asteroids from the debris spreading out our way and wrecking havoc!

OTOH, could such a collision knock the dense atmosphere off Venus and split the Cytherean world into two separate fragments – a binary planet each maybe about half to two-thirds of an Earth-mass and possibly habitable?

Perhaps such a collision – happening quickly enough could blast enough mass away from Venus – along with its atmosphere and cause it to spin quicker turning it into a Haumea-like terrestrial planet with small moons a much smaller mass letting some of that stifling air out and thus less pressure cooker conditions and perhaps turning it into something almost habitable? (Hmm.. then again, the chances of retaining volatiles eg. water in such a scenario are kinda remote.)

Or instead would the Moon and Venus fuse – maybe at slower speeds into one double earth-mass planet which could spin faster and have different qualities maybe becoming better or maybe much worse than now – once the new lava oceans cooled solid? (Which may take some time.) Such a world would be worse out at venus’es orbital distance -all that extra mass and the same heat can’t lead to much that’s good – but perhaps if this fused LunaVenus could moved out to Mars or the asteroid belt’s distance somehow that greater mass and a thick atmosphere – assuming outgassing – might work out nicely. Except for one thing – how would we shift it by Earth without altering our orbit in the process!

I wonder – has anyone ever modelled this sort of Venus-Luna planetary encounter of the impactful kind? 8)

goo.gl/LQAsN (my flickr acct)

And they’re going to be even closer next month and the month after that?
Awesome!

I can imagine someone getting a shot of the sky that shows the Moon, Venus, and Jupiter all in a row in the sky…..

As soon as I looked at the images on the computer, I thought to myself: “Phil Plait is totally going to post on this tomorrow.” Looks like I was right!

Been away from your blog for a while, Phil. Nothing personal. Still read it every day, just don’t have as much time to post here as I used to. Had things going on. All is well. Keep up the good work! And let us know next time you’re in Austin. I’ll buy you another drink!

- Greg

8)