1 - a. The Big Bang Theory is a theory on how the universe was created. It is an accepted view on how the
universe began. It states that the universe began approximately 13.7 billion years ago.
2 - b. At the center of every planet you can find the most dense elements because when planets are formed
the dense elements sink to the center while less dense elements float to the surface.
3 - c. Asteroids are objects that orbit our sun. They must orbit at the same speed as Jupiter otherwise they
would be crushed by Jupiter as both are on the same orbital path.
4 - a. The three main categories for asteroids are the Greeks, Trojans and Hildas.
5 - b. A Meteroid is a chunck of rock floating in space. They are not large enough to be called asteroids so
they are given a new name.
6 - c. The proper definition for a planet is: A celestial body moving in an elliptical orbit around a star.
Therefore earth is an example of a planet because it orbits around the sun.
7 - d. A dwarf planet is a planet like object that does not fit the description of a planet or a satellite.
Unlike a planet dwarf planets have not cleared their orbital regions.
8 - a. Comets are objects in space which are made of mainly rock and ice. They orbit the sun in very
elliptical orbits, for example Halley's comet which is visible once every 75-76 years.
9 - c. Albedo refers to the reflictivity of an object. The earth reflects many of the rays and therefore has
a high albedo.
10 - d. Scientists belive the earth is approximately 4.54 Billion years old.
11 - b. Pluto is a popular dwarf planet, however it only became a dwarf planet in 2006 when scientists found
a larger dwarf planet that was further than pluto.
12 - c. It is believed that the galatic center or the rotational center of the milky way galaxy is a massive
13 - d. It is believed that the moon was formed by an impact with a body called Theia which is the size of
mars. During this impact part of the earths crust broke off into space and started to orbit earth.
14 - a. Jupiter is the largest planet in our solar system with a radius of approximately 70,000 km.
15 - d. Mercury is the smallest planet in our solar system with a radius of approximately 2440 km.
16 - b. When a radar image is black the surface of the planet is very smooth because it did not reflect the
waves back but instead they bounced away.
17 - d. When making a photographic map you must start by outlining the morphology and identifying them.
18 - a. Morphology refers to the shape.
19 - c. The principal of superposition refers to the order of events. For example if there were multiple
impact craters, you would use the principal of superposition to determin which order they occured.
20 - d. The three different types of galaxies are Spiral, Irregular and Elliptical.