1. Mars Exploration Prof. David Cohen, Swarthmore College Presentation for Westtown Lower School February 12, 2004

2. What is astronomy? Study of the stars, moon, planets, sun & everything else in outer space When we look up in the sky at night, we see mostly stars…but ancient people noticed a few “stars” that wandered around the sky over the course of the year; the ancient Greeks called them planets MARS

4. The Moon is the biggest thing we usually see in the night sky

5. Questions we want to think about today: What are planets like? How big and far away are the planets, especially Mars (and let’s compare this to the Moon) Are there good conditions for life on Mars? Now? In the past? How are we exploring Mars and what are we finding out?

6. Stonehenge in England: over the years, people have built monuments to the sky, and observatories for watching it

7. Today’s observatories are big telescopes on mountaintops

8. And even spaceships: This is Apollo 11 about to land on the Moon See the Earth in the distance?

9. Artist’s vision of a spaceship landing on Saturn’s moon Titan

10. And today, we’ve got robots on Mars discovering what that planet is (and was) like Artist’s conception of the rover Opportunity

11. Before we look at what’s being discovered on Mars, let’s look at what Mars is (and compare it to the Earth and Moon), and also let’s look at how big and far away it is. MARS

12. The Earth and Mars are just two of nine planets in the solar system – planets are huge balls of rock, metal, and gas. Earth Mars

13. The Earth is a planet too – it’s a round ball, about 15,000 miles across, made up of rock, metal, water, air,…

14. The Earth, has an atmosphere and oceans – we couldn’t have life on Earth without them

15. The Moon does not have any air or water: there is not and cannot be any life on the Moon

16. Mars does have an atmosphere (though it’s thinner and different than ours on Earth).

17. The big question is: Does Mars have water? Gullies from running water in the past? Polar icecaps

18. To learn more, we’d like to go to Mars – first with robots, then maybe with people How hard is it to get to Mars?

19. The Earth and Mars are just two of nine planets in the solar system – How big is the solar system? Earth Mars

20. The solar system is big, and the planets are spread out

21. The solar system is so big…what if we made a scale model of it? The Sun (a million miles across) could be the size of a beach ball. The Earth (15,000 miles across) would be the size of a small marble. The Moon (half as big as the Earth) would be an even smaller marble. Mars is bigger than the Moon but smaller than Earth. How far apart would the Earth and Moon be on this scale? How far from the Sun would they be? How far away would Mars be?

22. Picture of the Earth and Moon taken from Mars

23. A spaceship can fly to the Moon in a few days, but to go to Mars takes more than a year. Can you imagine going on a trip that took a year…each way? Mars launch movie

24. Artist’s rendition of one of the spaceships landing

25. NASA’s animation of the rovers’ entry into the atmosphere of Mars and their landinganimation entry movie

26. Spirit Opportunity

27. Exposed bedrock at the Opportunity landing site – very old rock…is it sedimentary (meaning formed in water)? Sedimentary rocks on the Earth

28. Opportunity photographing the bedrock outcropping Bedrock movie

29. Spirit checking out a rock

30. This picture taken by Opportunity is only an inch across Could this small round pebble have been formed by water?

31. And another animation of the rover moving onto the surface of Marsanimation Rover moving onto surface movie

32. Animation of the robotic rover Robot animation

33. Come to the College’s telescope open house the second Tuesday of each month at Sproul Observatory at Swarthmore College.Sproul Observatory

35. More pictures of gullies on Mars…maybe caused by water flowing on the surface of the planet

36. There are dormant volcanoes on Mars too

38. The so-called “face on Mars”

39. A better picture shows that it’s not a face at all