Aliens!

4. someone who studies the physics of space
6. a spacecraft orbiting a planet
7. the universe is ______________ of years old
10. a 1979 film starring Sigourney Weaver
13. someone not from Earth
16. a way of relating space and time
19. how the universe began
21. a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity
22. someone from Mars, may or may not be named Marvin
24. unidentified flying object
25. a disk-shaped UFO is called a flying _______
26. a town in New Mexico infamous for alleged alien activity
27. concept that proposes a barrier to the development of life that makes it unlikely to find extraterrestrial civilizations
28. a hypothetical structure that connects distant points in spacetime
31. the magnetic field surrounding and protecting Earth

1. the mathematical formula for the probability of finding life
2. the gases that shield and protect Earth
3. the book "War of the _____________" was broadcast on the radio and made Americans think aliens were attacking
5. a human exploring space
8. a ship...for going into space
9. the contradiction between the high likelihood for extraterrestrial intelligence and the lack of evidence for it
11. a planet outside of our solar system
12. the area around a star where liquid water can exist on the surface of a planet is called the __________________ Zone
14. a rare and extreme black hole
15. how far light travels in 1 year
17. someone who studies space
18. someone from Earth
20. a classification scale for hypothetical alien civilizations
23. a baby star
29. the planet we humans live on
30. the stereotypical color of a fictional alien