Contents
- Preface
1Science and the Universe: A Brief Tour
2Observing the Sky: The Birth of Astronomy
7Other Worlds: An Introduction to the Solar System
13Comets and Asteroids: Debris of the Solar System
14Cosmic Samples and the Origin of the Solar System
18The Stars: A Celestial Census
20Between the Stars: Gas and Dust in Space
21The Birth of Stars and the Discovery of Planets outside the Solar System
27Active Galaxies, Quasars, and Supermassive Black Holes
- AHow to Study for an Introductory Astronomy Class
- BAstronomy Websites, Images, and Apps
- CScientific Notation
- DUnits Used in Science
- ESome Useful Constants for Astronomy
- FPhysical and Orbital Data for the Planets
- GSelected Moons of the Planets
- HFuture Total Eclipses
- IThe Nearest Stars, Brown Dwarfs, and White Dwarfs
- JThe Brightest Twenty Stars
- KThe Chemical Elements
- LThe Constellations
- MStar Chart and Sky Event Resources
- Index
Figuring for Yourself
Figuring for Yourself
49.
Suppose Earth took exactly 300.0 days to go around the Sun, and everything else (the day, the month) was the same. What kind of calendar would we have? How would this affect the seasons?
50.
Consider a calendar based entirely on the day and the month (the Moon’s period from full phase to full phase). How many days are there in a month? Can you figure out a scheme analogous to leap year to make this calendar work?
51.
If a star rises at 8:30 p.m. tonight, approximately what time will it rise two months from now?
52.
What is the altitude of the Sun at noon on December 22, as seen from a place on the Tropic of Cancer?
53.
Show that the Gregorian calendar will be in error by 1 day in about 3300 years.