Module 1 Flashcards
What does the Hubble Space Telescope photo show?
Thousands of galaxies in a region of the sky so small you could cover it with a grain of sand held at arm’s length.
What is the fourth learning goal of Chapter 1?
The Human Adventure of Astronomy: How has the study of astronomy affected human history?
What was the historical belief about Earth’s position in the universe?
Earth was imagined to be stationary at the center of a relatively small universe.
What does a galaxy consist of?
A great island of stars in space, all held together by gravity and orbiting a common center.
What is the Milky Way Galaxy?
A relatively large galaxy containing more than 100 billion stars.
What is the Local Group?
A collection of more than 70 galaxies, including the Milky Way.
What are superclusters?
Clusters of galaxy clusters, regions where galaxies and galaxy clusters are tightly packed.
What is the definition of an astronomical unit (AU)?
Earth’s average distance from the Sun, about 150 million kilometers.
What is a light-year (ly)?
The distance that light can travel in one year, approximately 10 trillion kilometers.
True or False: A light-year is a unit of time.
False: A light-year is a unit of distance.
What does the speed of light measure?
Light travels at approximately 300,000 kilometers per second.
How long does it take light to travel from the Sun to Earth?
About 8 minutes.
What can we infer about distant galaxies?
The farther away we look, the further back in time we see.
What is the significance of studying the Orion Nebula?
It is a giant cloud where stars and planets are forming, located about 1350 light-years away.
What are the three steps in the mathematical problem-solving process?
- Understand the problem
- Solve the problem
- Explain your result
Define a star.
A large, glowing ball of gas that generates heat and light through nuclear fusion in its core.
What is a planet?
A moderately large object that orbits a star and shines primarily by reflecting light from its star.
What distinguishes a dwarf planet from a planet?
A dwarf planet has not cleared most other objects from its orbital path.
What is a comet?
A relatively small and ice-rich object that orbits a star.
What is an asteroid?
A relatively small and rocky object that orbits a star.
What is a solar system?
The Sun and all the material that orbits it, including planets, dwarf planets, and small solar system bodies.
Define small solar system body.
An asteroid, comet, or other object that orbits a star but is too small to qualify as a planet or dwarf planet.
What constitutes a solar system?
The Sun and all the material that orbits it, including planets, dwarf planets, and small solar system bodies.
What is a star system?
A star (sometimes more than one star) and any planets and other materials that orbit it.