4.21 Astro 1 Section 1 Professor Brandt

4.21 Astro 1 Section 1 Professor Brandt - Astro 1 Section 1...

Info icon This preview shows pages 1–2. Sign up to view the full content.

Astro 1 Section 1 Professor Brandt Wednesday April 21th 1999 Announcements: Lecture notes: Lecture 42. Earth's Moon Mean distance = 384000 km. Period relative to stars (sidereal) = 27.3 days. Period as seen from Earth (synodic) = 29.5 days. 1/4 radius of Earth = 1740 km. 1/80 mass of Earth = 7.35 E22 kg. A bit less dense than Earth = 3360 kg/m 3 When looking at Moon see dark and light patches. Lunar lowlands are smooth dark. Highlands are battered by craters. The flat dark plains of the lunar lowlands are known as maria = "seas" in Latin. Early in Moon's history large meteor impacts blasted out craters lava rose up from inside Moon to fill these somewhat leading to darkness and lack of craters (since cratering heavier early on). History of Earth's Moon . Dominant fact is that Moon is small size. When moon formed it was molten and heavy elements sank to the middle. (4.1- 4.5 billion years ago.) Today may be slightly molten in the middle but not too much. Also studies of Moon's density and magnetic field rule out the presence of a
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern