Across
- 4. large cloud of interstellar gas and dust that collapses on itself, due to is own gravity, and forms a hot, condensed object that will become a new star
- 5. huge collection of gas, dust, stars, and dark matter; held together by gravity.
- 7. all of space and everything in it
- 11. when a planet or moon travels around the sun one time
- 15. roughly egg-shaped galaxy with no disk (flattened circular volume of stars); no obvious structures other than a dense central nucleus.
- 17. streak of light produced when a meteoroid falls toward Earth and burns up in Earth’s atmosphere
- 20. telescope that uses mirrors to focus visible light
- 22. natural satellite to Earth
- 24. a planet’s apparent backward movement in the sky
- 26. study of the universe, including its current nature, origin, and evolution, based on observation and the use of theoretical models
- 28. the average distance between the Sun and Earth
- 29. piece of interplanetary material that falls toward Earth and enters its atmosphere
- 31. whena planet or moon turns all the way around or spins on its axis one time.
- 32. an object that, due to its own gravity, is spherical in shape, orbits the Sun, is not a Satellite, and has not cleared the area of its orbit of smaller debris
Down
- 1. when the moon passes between Earth and the Sun and the Moon casts a shadow on Earth, blocking Earth’s view of the Sun
- 2. most common type of galaxy in the universe; characterized by disk shapes with spiral arms.
- 3. rocky surfaced, relatively small, dense inner planets closest to the Sun -- Mercury, Venus, Earth, Mars
- 6. when Earth passes between the Sun and the Moon, and Earth’s shadow falls on the Moon; occurs only during a full moon
- 8. large, gaseous planet that is very cold at its surface; has ring systems, many moons, and lacks solid surfaces -- Jupiter, Saturn, Uranus, Neptun
- 9. theory that proposes the universe began as a single point and has been expanding ever since
- 10. consists of a star (ex: sun) and other objects (planets, moons, asteroids, comets and meteoroids
- 12. the process in which a heavy nucleus divides to form smaller nuclei and one or two neutrons and produces a large amount of energy
- 13. occurs when Earth intersects a cometary orbit and comet particles burn up as they enter Earth’s upper atmosphere
- 14. a small fragment of an orbiting body that has fallen to Earth, generating heat; does not completely burn up in Earth;s atmosphere and strikes Earth’s surface, sometimes causing an impact crater
- 16. region of the space that lies outside the orbit of Neptune, 30 to 50 AU from the Sun, where small solar system bodies that are mostly rock and ice probably formed
- 18. telescope that uses lenses to focus visible light
- 19. tide that occurs during first- or third-quarter moon, when the Sun, the Moon, and Earth form a right angle; this causes high tides to be lower than normal and low tides to be higher than normal
- 21. hot condensed object at the center of a nebula that will become a new star when nuclear fusion reactions begin
- 23. small,rocky objects that orbit the sun that are left over from the early formation of our solar system; sometimes called minor planets
- 25. oval that is centered on two points called foci; the shape of planets’ orbits
- 27. occur during full or new moon, the Sun, the Moon, and Earth are all aligned; this causes high tides to be higher than normal and low tides to be lower than normal
- 30. small,eccentrically orbiting body made of rock and ice which have one or more tails that point away from the Sun