Planet Venus

1. Planet Venus

2. In Romanmythology, “Venus” was the goddess of love and fertility.

3. Venus was the equivalent of the Greek goddess, “Aphrodite”.

4. Venus was the consort of Vulcan…

5. …and Vulcan was the god of fire.

6. The word “volcano”comes from the word “Vulcan”.

7. Here we see Venuslocked in an embrace with Vulcan.

8. The Roman people are believed to descend from them.

9. For centuries, she has been called the “goddess of love”.

10. And in addition to that, she also goes by 2other nicknames.

11. Venus is sometimes referred to as the morning or evening star.

12. Under favorable conditions, Venus is so bright…

13. …that it can even cast a shadow on Earth.

14. After the Moon, Venus is the brightest object in the sky.

15. Venus star Notice how bright Venus is, when compared with a nearby star.

16. Venus also has a third nickname.

17. It is often referred to as “Earth’s sister planet”.

18. 100% 95% At 95% the diameter of Earth, the 2 planets are nearly the same size.

19. 100% 95% Venus also has 82% the mass of the Earth.

20. A History of Venus Complicated history; still poorly understood. Very similar to Earth in mass, size, composition, density, but no magnetic field Core solid? Solar wind interacts directly with the atmosphere, forming a bow shock and a long ion tail. CO2 produced during outgassing remained in atmosphere (on Earth: dissolved in water). Any water present on the surface rapidly evaporated → feedback through enhancement of greenhouse effect Heat transport from core mainly through magma flows close to the surface (coronae, pancake domes, etc.)

21. Venus is only the second planet in order of planets away from the Sun.

22. Most of the time, Venus is our closest neighbor in space.

23. 1 AU The averagedistance from the Earth to the Sun is 1 AU.

24. 0.72 AU However, Venus’ averagedistance is only 0.72 AUs from the Sun.

25. 1.00 AU _______ = 1.39 x closer 0.72 AU 0.72 AU This makes Venus1.39x closer to the Sun than the Earth.

26. (1.39)2 =1.93 x bigger 0.72 AU In being 1.39x closer to the Sun, the Sun appears to be 1.93x bigger.

27. The Sun as seen from Earth This is how big the Sun appears when viewed from Earth.

28. The Sun as seen from Venus The Sun as seen from Earth 1.93 x bigger And here’s how big the Sun appears when viewed from Venus.

29. When Venus and the Earth are both on the same side of the Sun…

30. …then Venus is the Earth’sclosest neighbor in space.

31. 1.00 AUs – 0.72 AUs = 0.28 AUs 0.28 AUs At this location, Venus is only 0.28 AUs from Earth.

32. However, when Venus is on the opposite side of the Earth…

33. …then Venus is no longer the closest planet to the Earth.

34. At this location, Venus lies 1.72 AUs from the Earth.

35. 1.00 AUs + 0.72 AUs = 1.72 AUs 0.72 AUs 1.00 AUs At this location, Venus lies 1.72 AUs from the Earth.

36. greatest elongation (aphelion) When at its greatestelongation…

37. greatest elongation (aphelion) 47o Venus isnever foundmore than 47o away from the Sun.

38. least elongation (perihelion) And when at its leastelongation…

39. 39o least elongation (perihelion) Venus isnever foundmore than 39o away from the Sun.

40. No matter where Venus is found in its orbit…

41. midnight …Venus is never visible when viewed from the Earth at midnight.

42. noon Venus is also never visible when viewed from the Earth at noon.

43. noon No planets are visible in the daytime sky…

44. noon …because the Sun’s lightdrowns them all out.

45. So at what time of the day would Venus be visible from the Earth?

46. 6 AM 6 PM Only in the mornings or in the evenings.

47. 6 AM 6 PM And only when Venus is in one of these positions.

48. 6 AM 6 PM This is why Venus is sometimes referred to…

49. 6 AM 6 PM …as the morning or evening star.

50. This photo tracks Venus over a 7 month period of time.