Question 1
Comets are made up primarily of ________.
◦ iron-nickel alloys
◦ frozen hydrogen
◦ silicate minerals, like rocks on Earth
◦ frozen water, carbon dioxide, and methane
Question 2
The Oort cloud is ________.
◦ the outer solar system where planetesimals, rocky debris and comets orbit outside beyond the outer planets but cross into the inner solar system at times
◦ an unusual type of cloud formed when meteorites strike Earth
◦ the asteroid belt
◦ another name for the inner solar system, just before the Sun became hot enough for nuclear fusion