Lecture8

Astronomy 1 – Fall 2014

Lecture 8: October 30, 2014

A Job Offer (Apply only if you scored > 60% on midterm 1.)

You Are Invited! •

Astro 1 Observing Session (Optional, Just for Fun) • WHEN: November 13th at 7-9pm •

•

•

Same time Nov. 20th if the 13th is cloudy

WHERE: Broida rooftoop; take elevator to 6th floor. Turn right as you exit the elevator. Go up the stairs. A TA will great you. WHAT: 3 Celestron C8 Schmidt-Cassegrain telescopes and one C11. • • •

Andromeda Galaxy, Uranus, Mars, Crab Nebula, Pleides, etc. Help identifying the Celestial Equator, NCP (& Polaris), and the Ecliptic Constellations: Pegasus, Taurus, Summer Triangle, Orion, etc.

• Will you be able to see the moon?

Previously on Astro 1 Solar System Formation: the nebular hypothesis. The Sun: formed by gravitational contraction of the center of the nebula.

Terrestrial planets: formed through accretion of dust particles into planetesimals, then into larger protoplanets.

Jovian planets: Began as rocky protoplanetary cores, similar in character to the terrestrial planets. Gas then accreted onto these cores.

Alternatively, they formed directly from the gases of the solar nebula. In this model the cores formed from planetesimals falling into the planets.

Today on Astro 1 • • • •

What does the Moon look like? What is the Moon made of? How did the Moon form? Tidal forces • What they are • Affect on Earth • Affect on Moon

The Moon’s Rotation and Libration •

Wobbles back and forth due to the elliptical shape of its orbit.

•

Nods up and down because rotation axis is not exactly perpendicular to its orbit.

The Moon Appears to Wobble & Nod

How Well Do You Know the Moon?

You are living at a moon base and watch the motions of the Earth and Sun in the lunar sky. What would you see? A. The Earth and the Sun would rise and set once a lunar month.

B. The Earth would rise and set once a lunar month, but the Sun would not appear to move significantly in the lunar sky. C. The Earth would not appear to move significantly in the lunar sky, and the Sun would rise and set once a lunar month. D. The Earth and Sun would not appear to move significantly in the lunar sky. E.

Q10.2

None of these answers are correct.

The astronaut footprint on the Moon shown in this photograph will probably A. exist for >10,000 years because there is very little weathering on the Moon. B. exist for >10,000 years because the Moon’s surface is hard and durable. C. exist for 10,000 years because the Moon’s surface is hard and durable. C. exist for