ASTR 101 Lecture Notes - Lecture 39: Hershel Greene, Tidal Locking, Orbital Period

• School: University of Victoria
• Department: Astronomy
• Course: ASTR 101
• Professor: Travis Martin

Document Summary

Magnetosphere: 1/20 of jupiter due to small metallic h (not enough gravity). Dynamo effect predicts n and s poles pointed in specific directions due to solar system. Gravitational effects balance them out and keep them from clumping. Ro(cid:272)he li(cid:373)it: fi(cid:374)al fate of a(cid:374)(cid:455) (cid:373)oo(cid:374) that gets too (cid:272)lose to a pla(cid:374)et. Moon are held together by a) own gravity b) molecular forces (also holds own rocks together). Tidal forces increase as moon closer to planet. Eventually tidal distortion greater than internal force (tidal bulge of our moon is larger than it should be for its distance produced when moon was closer to earth than it was now). Roche limit: boundary where this occurs distance of roche limit depends on planet and moon size. Rips apart moon and you get a ri(cid:374)g. satur(cid:374)"s ro(cid:272)he li(cid:373)it is (cid:1005)44 (cid:1004)(cid:1004)(cid:1004) k(cid:373) (7000 km further from outermost ring). Moons: 8 over 300 km in diameter, >53 others.