Answer:
11. True
Comets orbit the Sun just like planets and asteroids do, except a comet usually has a very elongated orbit. As the comet gets closer to the Sun, some of the ice starts to melt and boil off, along with particles of dust. These particles and gases make a cloud around the nucleus, called a coma.
12. False
13. True
14. True
The solid, core structure of a comet is known as the nucleus. Cometary nuclei are composed of an amalgamation of rock, dust, water ice, and frozen carbon dioxide, carbon monoxide, methane, and ammonia. As such, they are popularly described as "dirty snowballs" after Fred Whipple's model.
15. False
A comet does not give off any light of its own. ... Sunlight bounces off the comet's ice particles in the same way light is reflected by a mirror. A few comets come close enough to the Earth for us to see them with our eyes. Halley's Comet, for example, can be seen from Earth every 76 years.
16. True
Comets do not melt in the strict sense of becoming liquid. However, since they are composed partly of ice and other volatile compounds, they vaporize (turn directly to gas) when warmed in the vacuum of space by passing near the sun. ... Sometime the comet completely disintegrates.
17. True
Bondoc is a mesosiderite found on the Bondoc Peninsula, Philippines, and obtained by H.H. Nininger in 1962. Over 850 kg of the meteorite was recovered, 550 kg of which is now housed at the Center for Meteorite Studies.
18. False
An asteroid is a small rocky object that orbits the Sun. ... An asteroid is a small rocky object that orbits the Sun. A meteor is what happens when a small piece of an asteroid or comet, called a meteoroid, burns up upon entering Earth's atmosphere.
