Why Space? (and a little perspective)
Perspective The Earth was small, light blue, and so touchingly alone, our home that must be defended like a holy relic. The Earth was absolutely round. I believe I never knew what the word round meant until I saw Earth from space. - Aleksei Leonov, USSR
Perspective A Chinese tale tells of some men sent to harm a young girl who, upon seeing her beauty, become her protectors rather than her violators. That's how I felt seeing the Earth for the first time. I could not help but love and cherish her. Taylor Wang
Perspective It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small. Neil Armstrong (Apollo XI) The view of the Earth from the Moon fascinated me a small disk, 240,000 miles away.... Raging nationalistic interests, famines, wars, pestilence don't show from that distance. Frank Borman (Apollo VIII)
The Earth A Pale Blue Dot http:// www.youtube.com/ watch? feature=player_emb edded&v=p86bpm 1GV8M
Challenge and Legacy not because they are easy, but because they are hard - President Kennedy
What are the challenges? Space is a hostile environment Apollo astronauts dodged a bullet! Weightlessness, pressure, temperature, other local planetary conditions Space travel is expensive Shuttle costs $20,000 were per pound (AP 2003)! Cost over $10,000 to launch a CubeSat on a Russian Rocket Need a cheaper access to space ($1000 is better)
What are the challenges? Current space travel is slow For many missions: over 90% mass is fuel Must rely on gravity assists once we launch Voyager 2 took over 12 years to reach Neptune Power and communication difficulties Solar power is problematic beyond Mars Neptune is an 8 hour radio call (round trip) Communication requires large networks of telescopes (Deep Space Network)
What are the challenges? New technologies and new solutions are being developed. However, these require understanding the challenges of the environments
Our Local Inventory: What makes up our star system? 1) A single central star of type G (yellow-dwarf). 2) Two sub-stellar giant planets. (Jupiter & Saturn) 3) Two icy-gas hybrid planets. (Uranus & Neptune) All of the above planets have large systems of satellites; some planet sized. (Io, Europa, Ganymede, Callisto, Titan, and Triton) 4) Four much smaller rocky planets. (Mercury, Venus, Earth, & Mars) 5) Two areas of failed planetary debris a) one rock based (Asteroid Belt between Mars and Jupiter) b) one ice-based (Kuiper Belt starting at Neptunes orbit). 6) Several Dwarf Planets. (Pluto, Sedna, Quaoar) 7) An extended distribution of ejected debris. (Oort Cloud well past Pluto)
Solar System (Is this scale right?) 1. Yes 2. No
Asteroid Belt (rocks) Between Mars and Jupiter
Kuiper Belt Objects (Ice) Past Neptune
Oort cloud well beyond Pluto
Sun Venus Earth Mars Mercury
Sun Jupiter Saturn Uranus Neptune Pluto Missoulaè
The Sun and the Solar System Any study of the solar system must start with the Sun.. 1) The Sun contains 99.9% of all the mass in the solar system (Jupiter has most of the remaining 0.1%) 2) The Sun dominates energy (and light) production at all frequencies (except in radio waves where human activity is stronger!) 3) Solar energy largely determines the temperatures of every object in the solar system. 4) Material from the Solar Atmosphere is the dominant component of interplanetary space. Compared to the Sun, the planets are nearly inconsequential.. 17
Neptune Uranus Saturn Jupiter Earth The Sun Dominates the Solar System. Sol The places we are most interested in don t add up to very much Earth Venus Mars Ganymede Titan Mercury Callisto 18 Io Moon Europa Triton Pluto
Exploring our Star System How and Where? History is Written in what we see: The distribution, composition, and evolution of material in the solar system tells us how we got from a cold cloud of gas & dust to the present: 1) How did the Sun form and evolve? 2) How do planets form and where? 3) What does the distribution of planets and debris tell us about the early solar system? 4) How do planets change with time and what are the processes involved? 5) How does the interaction with the Sun affect conditions on a planet on various time scales? 6) What does our system tell us about others? 19
Now we can look at other solar systems First normal exoplanet found in 1995 As of 9/27/2012 there are 640 confirmed extra solar planets February 2011 Kepler scientists announced 1235 planets around 997 stars and now they are confirming that some are like the Earth. So far we haven t found a solar system like ours 20
Our Local Inventory: Where to learn more? We ll return to the members of the solar system later, but to learn more about the planets go to: www.seds.org/nineplanets/nineplanets www.solarviews.org www.exoplanets.org 21