Week 1: Overview of the Solar System

Question 1

Name the 3 dynamics of the solar system

Answer 1

1) Disk-like and cold
2) Low inclinations, all < 3.5 except Mercury with i = 7
3) Low eccentricities, all e < 0.1 except Mercury with e = 0.2

Question 2

Define: Mean Solar Day

Answer 2

The time taken for the sun to return to the highest point in the local sky

Question 3

Define: Sidereal Day

Answer 3

One Earth rotation wrt distant stars

Question 4

Explain what causes seasons, and name 3 common points

Answer 4

• The rotational axis is fixed as the planet orbits the Sun. So, due to their obliquities, the latitude point directly beneath the sun changes over time
• 1) Equinox: In Sept and Mar, The Sun passes directly above the Equator
• 2) Northern Winter Solstice: In Dec, N pole is tilted the furthest from the Sun
• 3) Northern Summer Solstice: In Jun, N pole is tilted the closest to the sun

Question 5

What’s the definition of a planet?

Answer 5

A celestial body that’s
1) In orbit around the Sun
2) Have sufficient mass to assume Hydrostatic eqm
3) Has cleared its orbital environment

Question 6

Explain the 2 measurement methods used to observe celestial bodies

Answer 6

1) Stellar Occultations: Detecting a decrease in brightness when a body passes in front of distant stars

2) Doppler Tracking: Detecting doppler shift in radio signals from a spacecraft when it’s moving past a body