Author Question: The orbits of most comets: A) are like the planets, fairly circular and in the ecliptic plane. ... (Read 31 times)

Sportsfan2111 · **on:** Jul 27, 2018

The orbits of most comets:

A) are like the planets, fairly circular and in the ecliptic plane.
B) lie almost entirely beyond the orbit of Neptune.
C) have perihelions within the orbits of Mercury.
D) go no farther out than Pluto, then return to the Sun again.
E) are shorter than the 76 year period for Comet Halley.

Question 2

Spiral arms are thought to be sites of ________, based on the observations of red HII regions and blue-white OB associations in and around these features.

Fill in the blank(s) with correct word