Astronomy

3. top layer
4. waves that travel through the earth.
10. liquid layer of the earth composed of primarily nickel and iron
12. when the earth makes one full rotation in relation to a distant star
13. 15-40 km thick; made of less dense granite.
14. after a year of the earth rotating on its axis it makes a full ________
15. solid ball of mostly iron and nickel, constantly expunging heat to rotate the outer core, causing the magnetic field
16. caused by the rotation of the liquid outer metallic core

1. shortest day with very little sunlight of the year
2. the separation of earth into layers of different densities with largest densities towards the center
4. a single day every time the observer is pointing back towards the sun
5. longest day with sunlight
6. a day late in the year where day and night are equal
7. molten rock and metal lying just beneath the lithosphere
8. a day early in the year where day and night are equal
9. 4 miles thick; made of dense basalt.
11. separtes the earth into eastern and western hemispheres