Across
- 1. millions or billions of stars held together in a group by their own gravity
- 4. occurs during the spring and fall, when day and night are approximately the same times (or are equal)
- 6. a unmanned exploratory spacecraft that send information about its environment back to earth
- 7. daily rising and falling of the sea level due to the location of the sun, moon, earth, and moon system
- 12. the force that attracts a body toward the center of earth
- 13. a man-made or natural object that orbits earth or another planet
- 14. a group of stars that form a pattern in the sky
- 15. a device that gathers visible light or another form of electromagnetic radiation
Down
- 2. a spacecraft designed to land on a planet's surface (ex. Mars rover)
- 3. suitable or good enough to live on or in
- 5. space and all of the matter and energy in it
- 8. layer of gases surrounding a planet
- 9. one part of a pattern of temperature changes and other weather trends over the course of the year
- 10. wide, flat zone of small particles that orbit around a planet's equator
- 11. occurs during the winter and summer, when the sun reaches the highest and lowest points in the sky at noon
- 15. the angle at which an object is positioned compared to its center axis (Earth = 23.5 degrees)