Origin of the Oceans I. Solar System? Copernicus. Our Solar System

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1 Origin of the Oceans I Our Solar System Solar System? To begin our study of the oceans, we must understand why they exist. Fundamental to this question is whether every planet has oceans, and, if not, why Earth does. Copernicus Nicholas Copernicus ( ) liked the heliocentric system of Aristarchus. He recognized that retrograde motion could be explained by the different times it takes the Earth to Orbit the sun compared to the other planets. Because Mars has a much greater Retrograde motion than other planets it must be closer than Jupiter and Saturn. Copernicus offered two major hypotheses Planets moved in circular orbits around the Sun The Earth spins on its axis 1

2 Retrograde Motion Retrograde Motion Brahe After Copernicus s ideas were published in 1543, there were many skeptics. One was Tycho Brahe ( ). He established an observatory in Denmark to mark detailed measurements of the planets in order to disprove Copernicus. (There were no telescopes at this time). These were the most accurate measurements on the movements of the planets upto date. He hired a mathematician Johannes Kepler to do astronomical calculations and after a while he suspected that Copernicus might be correct. He suspected that some force exerted by the Sun which exerted a control on the planets (this force is gravity but it had not been discovered at this time). 2

3 Kepler Kepler discovered three laws that describes planetary motions. The Law of the Ellipse- The orbit of a planet is described by an ellipse, and is not circular. The law of equal areas- A line drawn from the planet to the Sun sweeps out equal areas in equal times. A consequence of this is that a planet moves rapidly when close to the Sun and slower the further away it is. The law of orbital harmony- For any planet, the square of the orbital period is proportional to the cube of the planet s distance from the sun. The period of the Earth is days. (Leap year). The extra.24 days means that every 4 years we add an extra day. In addition every 450 years we need to day a further day. Galileo Galileo ( ) constructed a small telescope and with it made observations which sealed the fate of the geocentric universe. He observed the rotation of planets around Jupiter (i.e. the Earth could not be center of the universe) and that Venus went through phases like the moon which meant that it did not orbit around the Earth, but the Sun. Galileo also made observations about force. Motion is a result of a force and will only change if other force is applied. Galileo concluded that a force pulls all bodies with the same acceleration. Newton Issac Newton ( ) pulled all the pieces together. He concluded that the Moon moves around the Earth because it exerts a small force on the Moon which causes it to move towards the Earth. The was the force which Kepler thought might be magnetism. The law of gravity states that every body in the Universe attracts every other body. F= G M 1 M 2 / R 2. 3

4 Time Scales of Formation of the Universe Appearance of Space, Time, and Energy from single point 5.39X10-44 s (expansion to 1.6X10-35 m) Gravity s Inflation of Universe to 10cm s, still K Formation of atoms 800,000y (Temperature = 3000K) Formation of a Solar System Coalescence of dust and particles Rotation Heat Gravity Spinning disc of material Differentiation of particles Coalescence of planetesimal objects and asteroids Formation of a Solar System 4

5 Planetary formation During coalescence of planets, each one was developing unique characteristics Original nebulas had an abundance of different elements and some molecules As planets coalesced and cooled, gases escaped Smaller planets lost gases first Larger planetesimals created more internal heat and trapped it deep in their cores Planetary Differentiation Result is that each of the nine planets has unique characteristics (bear in mind that planetary and solar system formation is an on-going process) Mass(kg): e+30 Mass (earths): 332,830 Eq. radius (km): 695,000 Eq. radius (Earth = 1): Mean density (g/cm 3 ): Rotational Period (Earth days): Escape velocity (km/s): Luminosity (erg/s): 3.827e+33 Magnitude (Vo): Mean Surface Temperature ( o C): 6000 Age (billion years): 4.6 Principal Chemistry (%) Hydrogen: 92.1 Helium: 7.8 Oxygen: Carbon: 0.03 Nitrogen: Neon: Iron: Silicon: Professor Magnesium: Rosenheim EENS/EBIO Sulfur: Solar System: Sun 5

6 The Sun Life Cycle of a Star Energy produced by fusion- joining of two small nuclei to form a larger nucleus plus energy 2 H + 2 H = He (two Deuteriums fuse to Helium) When Hydrogen is spent, helium fuses to heavier elements (carbon, beryllium, oxygen, etc.) Temperature requirement is high for this type of fusion Eventually star explodes (supernova) and elements are available to rest of universe Mature Star Red Giant 6

7 Over-mature Star Close to Supernova Event The Planets: Mercury Mass(kg): e+23 Mass (earths): e-2 Eq. radius (km): Eq. radius (Earth = 1): e-1 Mean density (g/cm 3 ): 5.42 Mean distance from sun (km): 57,910,000 Mean distance from sun (Earth = 1): Rotational Period (Earth days): Orbital Period (days): Mean orbital velocity (km/s): Mean Surface Temperature ( o C): 179 Maximum Surface Temperature ( o C): 427 Minimum Surface Temperature ( o C): -173 Helium Sodium Oxygen The Planets: Venus Mass(kg): 4.689e+24 Mass (earths): Eq. radius (km): Eq. radius (Earth = 1): Mean density (g/cm 3 ): 5.25 Mean distance from sun (km): 108,200,000 Mean distance from the sun (Earth = 1): Rotational Period (Earth days): Orbital Period (days): Mean orbital velocity (km/s): Mean Surface Temperature ( o C): 482 Atmospheric pressure (bars): 92 Carbon dioxide (96%) Nitrogen (3+%) trace amounts of sulfur dioxide, water vapor, carbon monoxide, argon, helium, neon, hydrogen chloride, hydrogen flouride 7

8 Mass(kg): 5.976e+24 Mass (earths): 1 Eq. radius (km): 6378 Eq. radius (Earth = 1): 1 Mean density (g/cm 3 ): Mean distance from sun (km): 149,600,000 Mean distance from the sun (Earth = 1): 1 Rotational Period (days): Rotational Period (hours): Orbital Period (days): Mean orbital velocity (km/s): Mean Surface Temperature ( o C): 15 Atmospheric pressure (bars): Nitrogen (77%) Oxygen (21%) The Planets: Earth Earth s Peculiarities Rotation of Earth causes it to bulge at center (equator) Important Elements Differentiated during Earth s Formation Elemental radiometric clocks Uranium Thorium Radioactively unstable Parents decay into daughters If we know the rate of decay and the initial composition of the daughters, we know the age of a substance 8

9 Formation of Water on Earth Hot gases of newly formed compounds escaped the solid earth, trapped by gravity, and condensed when cooled Important Elements Differentiated during Earth s Formation Water H 2 O! Very important to Life Weather Habitability of Planet Earth Water formed on other planets What form? Did it stay? Life on Mars? 9

10 Life on Mars? Mass(kg): 6.421e+23 Mass (earths): e-1 Eq. radius (km): Eq. radius (Earth = 1): e-1 Mean density (g/cm 3 ): 3.94 Mean distance from sun (km): 227,940,000 Mean distance from the sun (Earth = 1): Rotational Period (days): Rotational Period (hours): Orbital Period (days): Minimum Surface Temperature ( O C): -140 Mean Surface Temperature ( o C): -63 Maximum Surface Temperature ( o C): 20 Atmospheric pressure (bars): The Planets: Mars Carbon dioxide (95.32%) Nitrogen (2.7) Argon (1.6) Professor Oxygen Rosenheim (0.2) EENS/EBIO Carbon 223 Monoxide (0.7) Water, Neon, Krypton, Xenon, Ozone Did Mars Have Water? Mars Rover Program (NASA) 10

11 Did Mars Have Water? If so, what happened to it? The Outer Planets: Jupiter Mass(kg): 1.9e+27 Mass (earths): e2 Eq. radius (km): Eq. radius (Earth = 1): 11.2 Mean density (g/cm 3 ): 1.33 Mean distance from sun (km): 778,330,000 Mean distance from the sun (Earth = 1): Rotational Period (days): Orbital Period (days): Mean Orbital Velocity (km/s): Mean Cloud Temperature ( o C): -121 Atmospheric pressure (bars): 0.7 Hydrogen (90%) Helium (10%) The Outer Planets: Saturn Mass(kg): 5.688e+26 Mass (earths): e1 Eq. radius (km): 60,268 Eq. radius (Earth = 1): e0 Mean density (g/cm 3 ): 0.69 Mean distance from sun (km): 1,429,400,000 Mean distance from the sun (Earth = 1): Rotational Period (hours): Orbital Period (years): Mean Orbital Velocity (km/s): 9.67 Mean Cloud Temperature ( o C): -125 Atmospheric pressure (bars): 1.4 Hydrogen (87%) Helium (13%) 11

12 Moons of Saturn and Jupiter Jupiter: 63 moons Diameter of Ganymede = 0.4(Earth) Saturn: 60 moons Rings are gravitationally trapped debris The Outer Planets: Uranus Mass(kg): 8.686e+25 Mass (earths): 14.5 Eq. radius (km): Eq. radius (Earth = 1): Mean density (g/cm 3 ): 1.29 Mean distance from sun (km): 2,870,990,000 Mean distance from the sun (Earth = 1): Rotational Period (hours): Orbital Period (years): Mean Orbital Velocity (km/s): 6.81 Mean Cloud Temperature ( o C): -125 Atmospheric pressure (bars): 1.2 Hydrogen (83%) Helium (15%) Methane (2%) The Outer Planets: Neptune Mass(kg): 1.024e+26 Mass (earths): 1.7e1 Eq. radius (km): 24,746 Eq. radius (Earth = 1): Mean density (g/cm 3 ): 1.64 Mean distance from sun (km): 4,504,300,000 Mean distance from the sun (Earth = 1): Rotational Period (hours): Orbital Period (years): Mean Orbital Velocity (km/s): 5.45 Mean Cloud Temperature ( o C): -193 to -153 Atmospheric pressure (bars): 1-3 Hydrogen (85%) Helium (13%) Methane (2%) 12

13 Pluto Planet or Not? Pluto and moon, Charon, are a binary system Other objects in the Kuiper belt are larger Recognition based in revolution plane of Neptune Summary There is one water planet Earth Planetary formation differentiated elements each planet contains Earth and Venus are very similar Mars once had water, evidenced by latest research The Outer Gaseous Planets are very different from the Rocky Inner Planets Scientific Notation! Summary 13