592
The 'ol 1 2 (mander.xyz)
you are viewing a single comment's thread
view the rest of the comments
[-] Animated_beans@lemmy.world 8 points 9 months ago

Pluto is smaller than Earth's moon. Should our moon be a planet too?

[-] Pegajace@lemmy.world 30 points 9 months ago* (last edited 9 months ago)

No, because absolute size is not what makes a moon a moon. Our Moon is a moon because it directly orbits a planet, not a star. Charon is massive enough relative to Pluto that the former does not directly orbit the latter, but instead they both orbit a common barycenter located between them, making them a binary planetary system.

[-] Frozengyro@lemmy.world 1 points 9 months ago

I mean the earth and moon do the same thing, just on a much smaller scale.

[-] Pegajace@lemmy.world 1 points 9 months ago

Not quite. All two-body systems orbit a common barycenter, but the mass ratio of the Earth-Moon system is so lopsided that the barycenter is inside the Earth, not between them like with Pluto and Charon.

[-] Zoidsberg@lemmy.ca 7 points 9 months ago

Does our moon independently orbit the sun?

[-] Zellith@kbin.social 5 points 9 months ago* (last edited 9 months ago)

The barycenter between earth and the moon is within the earths crust. The barycenter between charon and pluto is outside of plutos surface. For those who dont understand, this means that the center of gravity between the earth and moon is INSIDE the earth. So the moon orbits a point within the earth. Not so with the charon pluto system. Both worlds orbit a point in space.

If the moon was to have its own orbital path around the sun, then sure. It would be a planet imo. It's rounded by its own gravity... and it would orbit the sun.

But I guess if we want to the meat of the subject about what defines a planet in the most basic sense, it would be things that make Earth a planet, since we pretty much all agree Earth is a planet. So.. rounded... Orbits the sun... What else would you say describes the Earth?

[-] andthenthreemore@startrek.website 4 points 9 months ago

Gaia and Selene are double planets. Change my mind.

this post was submitted on 02 Dec 2023
592 points (100.0% liked)

Science Memes

10356 readers
1920 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.


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 2 years ago
MODERATORS