Last Words on SETI & CETI and some Space Travel Basics

1. Last Words on SETI & CETI and some Space Travel Basics HNRS 353 FALL 2018 Dr. H. Geller

2. What I Will Cover Today • Final words about CETI • Space Travel • Space Environment • Spaceflight Projects • Spaceflight Operations

3. Question • About how many extrasolar planets have officially been detected to date? • A between 10 and 100 • B between 100 and 1000 • C more than 1000

4. Question • How did we detect most extrasolar planets discovered before Kepler mission? • A Transits • B Hubble Space Telescope images • C the Doppler related technique

5. iClicker Question • Which technique does the Kepler mission use to search for Earth size planets around other stars? • A Transits. • B The astrometric technique. • C The Doppler related technique. • D Gravitational lensing.

6. iClicker Question • Nearly all the extrasolar planets discovered to date are • A terrestrial-like planets. • B jovian-like planets. • C large, icy worlds.

7. iClicker Question • The end result of a calculation with Drake equation is intended to be an estimate of • A the number of worlds in the galaxy on which life has arisen. • B the number of worlds in the galaxy on which intelligence has arisen. • C the number of worlds in the galaxy on which civilizations are transmitting signals now.

8. iClicker Question • Which of the following statements is true about the terms in the Drake equation? • A Astronomical research will soon give us firm values for all of the terms. • B Some of the terms depend on sociology, and cannot be determined by astronomers alone. • C We already know the terms of the equation to an accuracy within a factor of 2.

9. iClicker Question • The fact that marine predators like dolphins and sharks have similar shapes despite different ancestry is an example of • A convergent evolution. • B narrow bandwidth. • C spontaneous creation.

10. iClicker Question • Which of the following would lead an animal to a higher encephalization quotient (EQ) as it evolved? • A Growth in both body size and brain size. • B Growth in body size but not in brain size. • C Growth in brain size but not in body size.

11. iClicker Question • Two-way conversation with other societies is probably unlikely, even if we make contact. This is mainly because • A aliens won’t speak our language. • B it might be dangerous to get in touch. • C the time it takes for signals to cross the distance to them could be centuries or more.

12. iClicker Question • One reason the scientists doubt that crop circles have alien origin is • A they are always beautiful. • B they can be easily made by humans. • C their appearance is not correlated with sightings of bright lights.

13. A Cartoon about CETI

14. What does a telescope do? • Collect electromagnetic waves • Collecting ability proportional to the square of the diameter of the objective • Resolve electromagnetic sources • Related to the atmosphere, wavelength and curvature of the objective • Magnify surfaces of planets and the Moon • Magnification only of Moon, Sun and planets

15. Looking Beyond the Eyes

16. Optical Telescopes Reflector Refractor

17. Different Views of Sun Sun in Hydrogen-alpha Sun in X-ray

18. Radio Astronomy Basics

19. A Little More Detail

20. Jansky’s Original Radiotelescope

21. Grote Reber’s Telescope

22. 170 foot Diameter Radio-telescope at Green Bank, WV

23. The 100-meter Green Bank Telescope

24. Even Bigger than you Think

25. Jupiter in Radio Saturn in Radio

26. 3C296 Radio/Optical Composite

27. Smoothing Data

28. Visualizing the Data

29. Colorizing the Data

30. Dealing With Noise

31. Worldwide Noise Sources

32. The Space Environment • Solar System • Reference System • Gravity and Mechanics • Trajectories • Planetary Orbits • Electromagnetics

33. Solar System Considerations • Distance • From Sun • Energy, temperature, condensation of matter • Hostile Environment • Radiation (gamma ray) • Radiation (x-ray) • Radiation (UV)

34. Coordinate Reference Systems • Geographic • Celestial • Precession

35. Gravity and Mechanics • Orbits • Kepler • Newton

36. Orbital Transfers

37. Planets and Gravity

38. Flight Project Considerations • Mission Inception • Experiments • Spacecraft Classification • Telecom • Onboard Systems • Science Instruments • Navigation

39. Mission Inception

40. Instruments

41. Telecommunications

42. Onboard Systems

43. Operations Considerations • Launch • Cruise • Encounter • Extended Operations • Deep Space Network

44. Launch Vehicles

45. Cruise Portion of Mission

46. Encounter Portion of Mission

47. Need for Deep Space Network

48. Interstellar Spaceflight Considerations

49. THE PHYSICS AND MATH OF SPACE TRAVEL For a spacecraft accelerating at a rate a, the velocity v reached and distance x traveled in a given interval of time t is: c = speed of light Accelerating at 1g = 9.8 m/s2: Crew Duration (yr) Earth Duration (yr) Range (pc) 1 1 0.02 10 24 3 - nearest stars 20 270 42 40 36,000 5,400 - center of Galaxy

50. Question • What does the letter “c” stand for in the equations shown? • A Speed of sound • B Speed of light • C A constant of unknown value • D A generic constant • E Speed of time