Modern Astronomy II

150 million kilometers is equal to 1 (a)   unit.

The average distance between Earth and the sun is about                                    million km.

(a)  

The Danish astronomer                                        made precise measurements of the locations of bodies in the solar system, especially Mars.

(a)  

The                                         motion of planets is when they appear to move eastward among the stars, then stop and reverse direction.

(a)  

The mass of an object is a measure of the total amount of             it contains.

(a)  

The Earth movement that causes night and day is called            .

(a)  

The planetary system of Ptolemy had the planets moving in circular orbits around                                   .

(a)  

The geocentric model of the solar system was proposed by the astronomers of ancient .

(a)  

Most of the moon’s surface is covered by       ,which are densely pitted, light-colored areas.

(a)  

The Earth is farthest from the sun on about July 4 at       

(a)