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ASTRONOMY QUIZ ANSWERS
So how well did you do?
Here're the facts.
- How far have spacecraft from Earth travelled into space?
Correct answer: Somewhat less than one Light-day
The planetary exploration missions Pioneer and Voyager have barely traveled beyond our Solar System. These are the fastest spacecraft ever launched from Earth. Even these spacecraft will take a very long time to travel one light-year. We don't have the knowledge or technology to send space probes or manned craft to even the nearest stars!
NASA hopes to continue to receive data from Voyager 1 and 2 through year 2014, when the electrical power on-board is expected to begin to run out.
- How have astronomers learned most of what they know about the stars, galaxies, and the universe?
Correct answer: By analyzing light and other electromagnetic radiation from space that reaches the vicinity of Earth.
See Question 1. We haven't been able to travel to the stars to observe them up close. We rely on electromagnetic radiation in the form of light, radio waves, x-rays, etc. that reaches the Earth or spacecraft orbits near Earth for most of what we know about the Universe. This is analyzed, and evaluated with what we know about physics. Theoretical models and hypotheses are developed based on these observations, and new observations are made to test those theories. Unlike most other physical scientists, astronomers cannot do controlled experiments to test their hypotheses.
- If you could travel in a space-ship at the speed of light away from the solar system, how long could you see the sun?
Correct answer: 30 years
The exact answer depends on your eyesight and observing conditions but most people could see the sun for about 30 years in reasonably good observing conditions. The sun is considered an average star. There are stars as much as 400,000 times brighter than the sun and others as much as 400,000 times fainter if they could all be seen at the same distance.
- Approximately how many stars does the Andromeda Nebula contain?
Correct answer: 100,000,000,000
The Andromeda Nebula (Galaxy) is often considered a twin of the Milky Way although it is a little larger. From the speed at which a star near the edge circles the center, we estimate that the mass of the Andromeda Nebula is equal to that of 100,000,000,000 to 1,000,000,000,000 stars like the sun.
- What term do we use for the average distance between Sun and Earth?
Correct answer: Astronomical Units
The average Sun-Earth distance is called the Astronomical Unit, abbreviated as 1 AU. In conventional measurements, 1 AU = 150 million kilometers, or about 93 million miles.
- How old is the earth?
Correct answer: 5,000,000,000 years
The oldest rocks we have found on earth are about 3.5 billion years old but meteors and lunar rocks are as old as 4,500,000,000 years old. We also calculate that the sun is about 5 billion years old and we believe that the sun, the earth, the moon, and the meteors, as well as all of the other components of the solar system, were created at about the same time.
- To reach another planet, a spacecraft must be aimed:
Correct answer: Where the planet will be when the spacecraft reaches it.
A spacecraft traveling to another planet becomes a miniature planet itself, traveling in an orbit around the sun. The shape of that orbit depends both on the direction and on the speed with which it leaves the earth. These must be adjusted so that the orbits of the spacecraft and the planet cross at a time when both bodies are at the same point.
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