The document discusses the essential requirements for life, such as chemical elements, liquid water, temperature, atmosphere, gravity, and volcanic activity. It explores the search for extraterrestrial life within our solar system, focusing on Mars, Europa, and Titan, as well as the discovery of exoplanets in the habitable zones of stars. The text also highlights methods of detecting exoplanets and considerations for potential intelligent alien life communication.

1. Life Beyond Earth

2. Our Solar System

3. Our Solar System

4. Our Solar System
The Planets

5. Our Solar System
The Planets

6. Our Solar System
The Planets Moons

7. Our Solar System
The Planets Moons

8. Our Solar System
The Planets Moons
Dwarf Planets

9. Our Solar System
The Planets Moons
Dwarf Planets

10. Our Solar System
The Planets Moons
Dwarf Planets

11. Our Solar System
The Planets Moons
Dwarf Planets Asteroids and Comets

13. What do we need for life on Earth?

14. What do we need for life on Earth?
• The right chemical elements
Oxygen Hydrogen
Carbon Iron
Silicon Nitrogen
Calcium

15. What do we need for life on Earth?
• The right chemical elements
Oxygen Hydrogen
Carbon Iron
Silicon Nitrogen
Calcium

16. What do we need for life on Earth?
• The right chemical elements
• Liquid water

17. What do we need for life on Earth?
• The right chemical elements
• Liquid water
• The right temperature range
0 - 100 Celsius

18. What do we need for life on Earth?
• The right chemical elements
• Liquid water
• The right temperature range
• An atmosphere
shields planet
traps heat

19. What do we need for life on Earth?
• The right chemical elements
• Liquid water
• The right temperature range
• An atmosphere
• Enough gravity

20. What do we need for life on Earth?
• The right chemical elements
• Liquid water
• The right temperature range
• An atmosphere
• Enough gravity
• Volcanic activity

21. What do we need for life on Earth?
• The right chemical elements
• Liquid water
• The right temperature range
• An atmosphere
• Enough gravity
• Volcanic activity
...The ‘Habitable’ Zone!

22. too close…

23. too far…

24. just right!

29. Now that we know what
a planet needs for life...

30. Now that we know what
a planet needs for life...
...what exactly are we
looking for on other
planets?

31. Micro-organisms!

32. Micro-organisms!
•Dominate terrestrial life
•Existed on Earth for
over 3.5 billion years

33. Micro-organisms!
•Dominate terrestrial life
•Existed on Earth for
over 3.5 billion years

34. Micro-organisms and extremophiles
Life exists at extremes
of:
–acidity / alkalinity
–salt solution
–pressure
–temperature
–1km below the surface
–darkness

35. Antarctica

36. Underwater
heat vents

37. What about finding life in our
solar system?

38. What about finding life in our
solar system?
Mars

39. What about finding life in our
solar system?
Mars Europa

40. What about finding life in our
solar system?
Mars Europa Titan

42. Exploration of Mars
Flyby (4 successes)

43. Exploration of Mars
Orbiter (11 successes)

44. Exploration of Mars
Lander (4 successes)

45. Exploration of Mars
Rover (3 successes)

46. Exploration of Mars
Opportunity’s Path

49. atmosphere
of CO2
in habitable zone
T range -127 to 17oC
water
water vapour
in ice caps
in craters
dry river beds

50. atmosphere
of CO2
in habitable zone
T range -127 to 17oC
water
water vapour
in ice caps
in craters
dry river beds

58. Methane on Mars
• Plumes of methane mean something has to
be generating methane
• Source = subsurface -- geological or
bacterial?
• http://www.nasa.gov/mission_pages/mars/
news/marsmethane.html

64. ESA Exomars (2009)
NASA Mars Science Laboratory (2010+)
Sample return missions (~2014)

66. Human missions to Mars (~2040)

68. Europa

69. Europa

70. Could
extremophiles
live on Europa?

71. Drill through ice without contamination = HARD!

72. NASA Jupiter’s Icy Moons Orbiter 2011+

73. Titan

74. Titan
• Thick methane
atmosphere with lots of
Nitrogen.
• Only other nitrogen
domiated atmosphere
except Earth
• May be pre-biotic
atmosphere, like early
Earth.
• Lakes of methane--good
organic solvent.

75. Exoplanets
Planets around stars other than our Sun in our galaxy,
the Milky Way

76. Exoplanets
Planets around stars other than our Sun in our galaxy,
the Milky Way ... about 500 so far!
August 2010

77. Exoplanets
Planets around stars other than our Sun in our galaxy,
the Milky Way ... about 500 so far!
detect by transit
detect by imaging
detect by radial velocity
August 2010

78. Detection Methods:
radial velocity
• Star moves because of
planet’s gravity pull
• Measure motion of star
along our line of sight to
get period of orbit

79. Detection Methods:
transit
• Planet moves in front of star during its orbit
• Light from star is dimmed because planet is
in front of it

80. Detection Methods:
direct imaging
• Take a picture of a planet around a star
• Hard to do because planets are faint and
stars are bright

83. Hot Jupiters
• Most extrasolar planets we have found are
“hot Jupiters”
• Most are 1 to 13 x Mass of Jupiter
• Most are located 10 x closer to their star
than Earth
• Most are around Sun-like stars (because
they are easily observed using radial
velocity)

84. Hot Jupiters
• Most extrasolar planets we have found are
“hot Jupiters”
• Most are 1 to 13 x Mass of Jupiter
• Most are located 10 x closer to their star
than Earth

85. Hot Jupiters
• Most extrasolar planets we have found are
“hot Jupiters”
• Most are 1 to 13 x Mass of Jupiter
• Most are located 10 x closer to their star
than Earth
• Most are around Sun-like stars (because
they are easily observed using radial
velocity)
• Densities are very different

86. Earth-like Planets
• Kepler Telescope lets us look for Earth-mass
planets in the habitable zone of other stars
• Also finds “super Earths” which are 1 to 10x
mass of Earth but are not gas balls
• More common than Jupiter-mass planets but
VERY new area of research

87. Earth-like Planets
• Are any of these planets actually like Earth?:
– Air, water, rocks, life, etc?
• Could we visit one of these planets?
– How? Why or why not?
• Could we communicate with one of these
planets?
– Have we tried already? How would we identify
communication from another planet?

88. Intelligent Alien Life
–Pioneer probes sent
out of solar system
–Best chance of
encountering
extraterrestrial life

89. Intelligent Alien Life
Plaque on Pioneer 10 probe

95. The End