Mercury

VENUS MARS EARTH

VENUS

VENUS VOLCANOES _ PANCAKE DOMES

MARS - THE RED PLANET

MARS: The Red Planet Mars is the 4th planet from the Sun and the seventh largest orbit: 227,940,000 km from Sun diameter: 6,794 km mass: 6.4219e23 kg Surface temperatures on Mars vary from 150 K (-220 F) to 295 K (70 F). Mars has a very thin atmosphere composed of : carbon dioxide (95.3%) nitrogen (2.7%), argon (1.6%) and traces of oxygen (0.15%) and water (0.03%). Mars has permanent ice caps at both poles composed mostly of solid carbon dioxide ("dry ice"). There may be water ice hidden below the surface at lower latitudes.

MARS VOLCANOES – SHIELD VOLCANOES

Giovanni Schiaparelli Described “canali” on Mars in 1877. He meant channels but “canali” has incorrectly been translated as “canals”.

WHAT ARE THESE SURFACE FEATURES?

Dunes Gullies Evidence of recent? water

LIFE ON MARS??

We must first ask some important questions! LIFE ON MARS? David McKay et al. (1996) announced the first identification of organic compounds in a Martian meteorite. The authors suggested that these compounds, in conjunction with other structures observed in the rock may be evidence of ancient Martian microorganisms. WAS THERE LIFE ON MARS? We must first ask some important questions!

How do we know the meteor was from Mars? It’s nearly certain that meteorite ALH 84001 is from Mars, even no rocks have ever been collected on Mars. The strongest evidence for its Martian origin is that ALH 84001 contains traces of gas that is just like the Martian atmosphere. The Viking Lander spacecraft analyzed the Martian atmosphere in 1976. It is different from the Earth’s atmosphere, or Venus’, or any other source of gas that’s ever been found.

What is the evidence for ancient Martian life? Carbonate globules that contain Polycyclic Aromatic Hydrocarbons (PAHs). These are organic molecules that are common products of the fossilization of microorganisms

a) carbonate globules b) fossil structures? The globules contains several unusual mineral phases commonly produced by microbes; When examined by an electron microscope, it reveals tiny sausage-shaped structures that resemble tiny microfossils. In addition, the features suggestive of biological activity all appear in the same locations with the rock.

How Good is the Evidence? Individually, each structure occurs in non-living systems; Together they are suggestive of life but - No structure resembles a cell or cell organelle. It is seems prudent to follow Carl Sagan’s advice: “ Extraordinary claims require extraordinary evidence.” At the present time the evidence is not good enough to substantiate claims of martian life

THE FACE ON MARS

a) Mercury b) Mars c) The Moon

The Gas Giants Jupiter Saturn Neptune Uranus

liquid water underneath? Jupiter’s Moon Europa Icy Surface. Do cracks indicate liquid water underneath?

The Earth is layered like an onion

How do we know that the Earth is a layered sphere? Data From Observation/Experiment Meteorite Data – meteorites at least 35% Fe. Earth’s Crust is only 6% Fe. Rocks brought up from Mantle by tectonic processes are denser than the crust. Moon Rocks – all data suggest that the Earth’s crust is too light. Stony -Iron Meteorites – appear re-melted & differentiated.

2) Hypothesis: The Iron Catastrophe The Early Earth is homogeneous & cool. The Earth begins to heat up due to: impacts from meteorites gravitational contraction radioactivity At 2000o C Iron melts and the Earth differentiates based on density. The light elements like Oxygen, Silicon, and Aluminum float to the surface to form the crust. The heavy elements like Iron sink into the center to form the core. The mantle is intermediate. 3) Let’s Test The Hypothesis that most of the Missing Iron is in the Core.

Eratosthenes Experiment Distance from Alexandria to Syene = 786km 7o = 1/50th of a circle (360o) 50 X 786km = 39,300 km Actual Circumference of Earth is 40,008 km

2) Volume = 4/3r2; volume in cm3 3) Mass = gr2/G; where: DENSITY OF THE EARTH 1)Circumference = 2r; radius in cm 2) Volume = 4/3r2; volume in cm3 3) Mass = gr2/G; where: g = gravitational acceleration (9.8 m/s2) r = radius (m) G = gravitational constant 6.7 X 10-11 4) Density = Mass (kg)/ Volume (cm3)

4) Density = Mass (kg)/ Volume (cm3) DENSITY OF THE EARTH 1) Circumference = 2r 40,008 km = 2 r; r = 6.37 X 108 cm 2) Volume = 4/3r3; V =( 4/3)(3.14)(6.37 X 108 )3 = 1.08 X 1027 cm3 3) Mass = gr2/G; M = (9.8)(6.37 X 106 )2 6.67 X 10-11 = 5.96 X 1024 4) Density = Mass (kg)/ Volume (cm3) D = 5.96 X 1024 = 5.5 X 10-3 kg/cm3 1.08 X 1027 = 5.5 X g/cm3

2) EVIDENCE FROM PRECESSION

EVIDENCE FROM SEISMIC WAVES

EVIDENCE FROM SEISMIC WAVES

INTERIOR OF THE EARTH

CONVECTION Energy Transfer where hot, buoyant material rises replacing cool, denser material, which sinks.