ASTR 310 Lecture Notes - Lecture 3: Semi-Major And Semi-Minor Axes, Escape Velocity, Solar Mass

• School: Athabasca University
• Department: Astronomy and Astrophysics
• Course: ASTR 310
• Professor: reew

Document Summary

P(cid:1007): co(cid:374)sider three h(cid:455)potheti(cid:272)al solar s(cid:455)ste(cid:373)s: a(cid:895) the su(cid:374) (cid:449)ith o(cid:374)e pla(cid:374)et of earthlike size, (cid:271)(cid:895) the su(cid:374) (cid:449)ith t(cid:449)o pla(cid:374)ets, jupiter a(cid:374)d earth, (cid:272)(cid:895) the su(cid:374) (cid:449)ith t(cid:449)o (cid:272)op(cid:373)a(cid:374)io(cid:374)s, a (cid:838)pla(cid:374)et(cid:839) of (cid:1004). (cid:1005) solar (cid:373)ass a(cid:374)d earth. I(cid:374) (cid:449)hi(cid:272)h s(cid:455)ste(cid:373) (cid:449)ould the earth-sized pla(cid:374)et (cid:373)ost (cid:374)earl(cid:455) o(cid:271)e(cid:455) kepler"s origi(cid:374)al la(cid:449)s: the earth-sized planet would most nearly obey kepler"s original laws in system a. We know that kepler"s laws apply to any situation in which a small body revolves around a star (or more massive body). These laws dominate if the planet is predominantly affected by the star and not under the influence of another large, nearby planet. System a ensures that the earth-sized planet would be exclusively under the influence of the sun"s gravity and, therefore, would obey kepler"s laws. P(cid:1005)(cid:1006): sho(cid:449) the (cid:448)elo(cid:272)it(cid:455) of earth i(cid:374) its or(cid:271)it arou(cid:374)d the su(cid:374) is a(cid:271)out (cid:1007)(cid:1004)k(cid:373)/s. The following equation is found on page 55, mathematical notes on circular.