739
Lmao (mander.xyz)
you are viewing a single comment's thread
view the rest of the comments
[-] expr@piefed.social 9 points 2 days ago

I assume it's not just about the gravity, but also the much larger radius of the planet would mean much larger distance from the surface, and thus much more fuel needed.

[-] potatopotato@sh.itjust.works 20 points 2 days ago* (last edited 2 days ago)

That's not how.......what???

F = G * (m1 * m2) / r^2

Note that radius is both squared and the dividing term. More distance = less gravity

[-] lemmyman@lemmy.world 9 points 2 days ago* (last edited 2 days ago)

Escape velocity does scale with (square root of) radius so its not a dumb thought.

And I'm not a rocket surgeon but I could imagine earth rockets might be operating near some physical limits that make a 50% increase (or whatever) infeasible.

https://en.wikipedia.org/wiki/Escape_velocity

[-] Lojcs@piefed.social 4 points 1 day ago* (last edited 1 day ago)

Wikipedia says energy = GMm/r.

if g=GM/r² then energy = mgr, proportional to r given g is constant.

apologiesMy previous comment was wrong, I derivated while integrating.

[-] expr@piefed.social 2 points 1 day ago

I stated an assumption and was contributing to the conversation. Even if that assumption is incorrect, there's no need to be a dick about it.

It seems like a larger atmosphere would result in a longer duration exposed to atmospheric drag, thus requiring more fuel to overcome it.

[-] turdas@suppo.fi 7 points 2 days ago

That's, uh, not really how that works. A taller atmosphere would mean you have to go through more of it, but unless it's not a terrestrial then the atmosphere won't be that much taller.

If it is a non-terrestrial planet, it's unlikely anyone would be building rockets on there to begin with.

[-] Pyr_Pressure@lemmy.ca 3 points 2 days ago

If it has a higher gravity would the atmosphere technically be lower since it will squish up closer to the planet?

[-] Crackhappy@lemmy.world 1 points 2 days ago

And your username would also be relevant.

You're sort of right. The change in distance from the surface is insignificant, but a spacecraft orbiting a bigger planet has to travel further with each orbit so its speed must be faster to avoid falling out of orbit, even if the gravitational acceleration at its orbital height is the same.

this post was submitted on 13 Apr 2026
739 points (100.0% liked)

Science Memes

19890 readers
1884 users here now

Welcome to c/science_memes @ Mander.xyz!

A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.



Rules

  1. Don't throw mud. Behave like an intellectual and remember the human.
  2. Keep it rooted (on topic).
  3. No spam.
  4. Infographics welcome, get schooled.

This is a science community. We use the Dawkins definition of meme.



Research Committee

Other Mander Communities

Science and Research

Biology and Life Sciences

Physical Sciences

Humanities and Social Sciences

Practical and Applied Sciences

Memes

Miscellaneous

founded 3 years ago
MODERATORS