AST101H1 : Notes on the sun + planets

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Stefan Mochnacki

Document Summary

escape speed does not depend on direction. orbits are a kind of free fall/falling. we have seasons because of earth"s tilt towards the sun thus receiving more direct sunlight: so july is warm because the northern hemisphere is tilted toward the sun receiving more direct sunlight and longer days. distance of earth from sun does not really change, does not affect seasons. we see phases of the moon because of its elliptical orbit around earth. we see one side of moon because of synchronous rotation, rotates once with each orbit. annual parallax of star: less than one arcsecond. hot gas = emission spectrum, hot dense object = continuous spectrum. venus: thick co2 atmosphere, mars: thin co2 atmosphere. plate tectonics help scrub carbon out of earth keeping it cooler than venus, making it possible for us to live. carbon cycles keeps earth"s temperature at a level we can live at.