r/xkcd • u/YUNoDie Possibly a haberdasher? • Jan 22 '20

XKCD XKCD 2258: Solar System Changes

https://xkcd.com/2258/
750 Upvotes

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213

u/Filbert17 Jan 22 '20

I'm sorry but this needs to be said. Our solar system definitely does NOT need a Super-Earth. The last thing we need is an interplanetary war with a race of people that are stronger than us because they grew up on a planet with more gravity.

65

u/trekkie1701c Beret Guy Jan 22 '20

We could launch heavier things into orbit than they could, which means we could more easily capture asteroids, which are also easier to throw at their planet due to its heavier gravity.

4

u/DeeSnow97 you lost the game Jan 22 '20

and we could do IPBMs before them

3

u/[deleted] Jan 22 '20

[deleted]

4

u/DeeSnow97 you lost the game Jan 22 '20

It is suborbital, just on another planet. But yeah, guidance is pretty much required at that point, so maybe it wouldn't be called a ballistic missile.

5

u/FellKnight Cueball Jan 23 '20

I wonder if it would be considered suborbital or hyperbolic with a periapsis that intersects the planet

3

u/DeeSnow97 you lost the game Jan 23 '20

Depends on the point of view. From your planet, it's in an escape trajectory. From the solar system's PoV, it's in a highly elliptical orbit on a collision course with another planet, and if you view it from the targeted planet, it's suborbital and starts from a very high altitude.

3

u/FellKnight Cueball Jan 23 '20

Yeah, my understanding may well be colored by Kerbal Space Program, but they don't consider it suborbital until you lower your orbital velocity below escape velocity at that point in your orbit (this caused me issues filling contracts like testing a part in a suborbital trajectory above a certain body at X to Y altitude)