1. ASTR100 (Spring 2006) Introduction to Astronomy Collecting Light with Telescopes Prof. D.C. Richardson Sections 0101-0106

2. Why do we put telescopes into space? It is NOT because they are closer to the stars!…

3. Observing problems due to Earth’s atmosphere 1.Light pollution.

4. Star viewed with ground-based telescope. View from Hubble Space Telescope. 2.Turbulence causes twinkling  blurs images.

5. 3.Atmosphere absorbs most of EM spectrum, including all UV and X-ray, most infrared.

6. Telescopes in space solve all three problems Location/technology can help overcome light pollution and turbulence. But nothing short of going to space can solve the problem of atmospheric absorption of light. Chandra X-ray Observatory

7. Adaptive optics Rapid changes in mirror shape compensate for atmospheric turbulence. How is technology revolutionizing astronomy? Without adaptive opticsWith adaptive optics

8. Adaptive Optics: Neptune WithoutWith

9. Interferometry Allows two or more small telescopes to work together to obtain the angular resolution of a larger telescope. Very Large Array (VLA), New Mexico

11. The Moon would be a great spot for an observatory (but at what price?)…

12. ASTR100 (Spring 2008) Introduction to Astronomy A Brief Tour of the Solar System Prof. D.C. Richardson Sections 0101-0106

13. What does the solar system look like?

14. The solar system exhibits clear patterns of composition and motion. These patterns are far more interesting than numbers, names, and other trivia!

15. Planets are very tiny compared to distances between them.

16. Sun Over 99.9% of solar system’s mass. Made mostly of H/He gas (plasma). Converts 4 million tons of mass into energy per second.

17. Mercury Made of metal and rock; large iron core. Desolate, cratered; long, tall, steep cliffs. Very hot and very cold: 425°C (day), –170°C (night).

18. . Venus Nearly identical in size to Earth; surface hidden by clouds. Hellish conditions due to an extreme greenhouse effect. Even hotter than Mercury: 470°C, both day and night.

19. Venus in Radar

20. An oasis of life. The only surface liquid water in the solar system. A surprisingly large moon. Earth & Moon to scale Earth

21. Mars Looks almost Earth-like, but don’t go without a spacesuit! Giant volcanoes, a huge canyon, polar caps, more… Water flowed in the distant past; could there have been life?

22. Rovers on Mars!

23. Jupiter Much farther from Sun than inner planets. Mostly H/He; no solid surface. 300 times more massive than Earth! Many moons, rings…

24. Moons can be as interesting as planets themselves, especially Jupiter’s four Galilean moons. Io (shown here): active volcanoes all over. Europa: possible subsurface ocean. Ganymede: largest moon in solar system. Callisto: a large, cratered “ice ball”.

25. Saturn Giant and gaseous like Jupiter. Spectacular rings. Many moons, including cloudy Titan. Cassini spacecraft currently studying it. Earth!

26. Saturn Rings are NOT solid; they are made of countless small chunks of ice and rock, each orbiting like a tiny moon. Artist’s conception

27. Saturn Cassini probe arrived July 2004. (Launched in 1997).

28. Uranus Smaller than Jupiter/Saturn; much larger than Earth. Made of H/He gas and hydrogen compounds (H 2 O, NH 3, CH 4 ). Extreme axis tilt. Moons and rings.

29. Neptune Similar to Uranus (except for axis tilt). Many moons, including Triton.

30. Pluto and Eris Much smaller than other planets. Icy, comet-like composition. Pluto’s moon Charon is similar in size to Pluto.

31. Comets & Asteroids Leftovers from planet formation. Tiny worlds of ice and/or rock. Some even have moons! Comet P/Tempel 1 Asteroid 25143 Itokawa

33. Quiz! Which body in the solar system has the most mass: A.Earth B.Jupiter C.The Sun D.The Moon