Across
- 6. When the earth crosses the tail of comet,swarms of meteors are seen.
- 8. are stony meteorites which do not
- 10. The body that reaches the earth is called.
- 11. meteorites, as their name suggests,
- 15. Which appear after nearly every 76 year. It was seen in 1986.
- 20. They are believed to have condensed directly out of the solar nebula, making them the most ‘pristine’ material in the Solar System.
- 23. is the fireball seen in the sky when a meteoroid collides with the Earth’s atmosphere.
- 27. He predicted that the Sun released a steady stream of charged particles with speeds of a few 100 km/s.
- 28. man-made satellite
- 31. is a piece of rocky space debris orbiting the Sun at typically 20 - 40 km/s,some of which are on a collision course with the Earth.
- 32. are composed of about 50% silicates and 50% iron, and make up only about 1% the of meteorite falls.
Down
- 1. are small Solar System bodies.
- 2. is the remnant of a meteoroid which has survived the fireball to impact on the Earth’s surface.
- 3. lead to suggest in the early 1600s that cometary tails were effected by the pressure of sunlight.
- 4. an explosion was felt hundreds of kilometers away and felled trees over an area of 2000 square kilometers.
- 5. are small spherical pebbles, generally 0.1 mm to 10 mm in size, found in the primitive chondrites.
- 6. As comets burn out*, dust and rock fragments form a compact which for many years continues to circle the Sun in the orbit of the parent comet.
- 7. make up the remaining 95% of meteorite falls, and are divided into three types: chondrites, achondrites & carbonaceous.
- 9. chondrules or volatiles and have far less iron than chondrites.
- 10. it is generally known as "shooting star" or "falling star".
- 12. a stream of ionised gas emanating from the Sun, was discovered ten years later in 1962.
- 13. There is large gap in between the orbit of Mars & Jupiter.
- 14. Crater would have had a diameter between 50 and 100 meters.
- 16. bodies that have been chemically sorted.
- 17. some larger meteoroids can actually explode in the air before they hit the ground.
- 18. are composed of silicate rock & rounded bits of glassy rock.
- 19. trace amounts of gas that resembles the atmosphere of Mars, which is trapped within microscopic pockets of the rocks.
- 21. tails of comets, point in a slightly different direction though still away from the Sun.
- 22. meteorites are extremely rare - less that 0.1% of all meteorites are of lunar origin.
- 24. carbon and some complex organic material. They can also contain as much as 20% water and other volatile compounds.
- 25. Earth are typically 10-20 times as large as the diameter of the meteorite which causes it.
- 26. formed when large meteorites strike
- 29. meteors are dust particles from the Temple-Tuttle comet.
- 30. meteorites are composed of about 90% iron and 10% nickel. They make up about 4% of the Earth’s meteorites.