ASTR 1P01 Lecture Notes - Angular Diameter

• School: Brock University
• Department: Astronomy
• Course: ASTR 1P01
• Professor: Bozidar Mitrovic

Document Summary

He argued that if these distances were comparable one would observe the following . And if the moon is revolving at a constant speed ( a reasonable assumption) the internal of time from third quarter moon to first quarter moon would be shorter than the interval from first to third quarter. But these intervals are nearly the same (about 2 weeks) By measuring the times between the quarter phases he determined angle a to be 87 degrees (the actual value is now 89 degrees and 57 minutes of the arc) The sun must be at greater distance than the moon. He used geometry to find out the ratio of distances, comparison of distance from sun to earth and moon to earth. Measure time it takes from third to first quarter and from first to third quarter. Sun 20 times more distant than the moon, sun has 20 time bigger diameter than the moon because have the same angular size.