Presentation on theme: "Welcome to the Solar System"— Presentation transcript:
1 Welcome to the Solar System A Celestial AlignmentWhy do they line up?Image from: ganymede.nmsu.edu/tharriso/ast110/class05.html
2 Moons also orbit in the same plane Jupiters equitorial bands show the eliptic (tilt = 0)Image:
3 Orbits in the EclipticThis also includes ring systems!
4 The Solar DiskSeen from a 100 AUSolar system is a dusty disk
5 The Layout of the Solar System Large bodies in the Solar System have orderly motionsplanets orbit counterclockwise in same planeorbits are almost circularthe Sun and most planets rotate counterclockwisemost moons orbit counterclockwise
6 The Layout of the Solar System Planets fall into two main categoriesTerrestrial (i.e. Earth-like)Jovian (i.e. Jupiter-like or gaseous)
11 The Layout of the Solar System Swarms of asteroids and comets populate the Solar System
12 Comets are found in two main Zones: The Kuiper BeltThe Oort CloudThe Oort cloud goes from 5000 to 50,000 AU or further!
13 When Comets are disturbed from their orbits.. They end up in eliptical orbits..Encounters with Jovian Planets speed them up or slow them down…The Oort Cloud is the “shell” of slow moving comets at aphelionSpeeds at aphelion might be a few cm/sec!If and when they approach the Sun, the move much faster!
14 They Also Grow Tails…Image from APOD (credit and copyright Jimmy Westlake)
15 Not everything fits perfectly The line between planet and comet is not clear!Pluto, Quoar, Viruna, Xenia, and Sedna are all Kuiper Belt objects (KBO’s)Or the Solar system has at least 13 planets…or 8 major planets and 5 + minor planets!Check out:Artists conception of Xenia and the Solar System…100AU from Sun. Note the 44 degree tilt of orbit.
19 A Few (more) Exceptions to the Rules… Both Uranus & Pluto are tilted on their sides.Venus rotates “backwards” (i.e. clockwise).Triton orbits Neptune “backwards.”Earth is the only terrestrial planet with a relatively large moon.Density decreases from Mercury outward, but Earth is more dense than any other planet!
24 Spacecraft Missions--categories Flyby – spacecraft “flies by” a world just onceOrbiter – spacecraft orbits the world it studieslonger-term study is allowedLander/Probe – spacecraft lands on the surface of the world or plunges through its atmosphereSample Return – spacecraft returns to Earth with a sample of the world it has studiedThese types of mission are listed in order of increasing cost.
25 Missions to Other Worlds Upcoming missions:Deep Impact:Crashed into comet Temple 1 JulyMars Reconnaissance Orbiter: Low orbit..one meter surface resolution! Launched Aug 12..Arives Nov 06.New Horizons: Orbiter to Pluto/Charon leave 2006 – arrive 2020!
26 Highlights of coming attractions Mercury’s extreme days and nights, tall steep cliffs, and large iron contentVenus’s extreme greenhouse effectEarth as an oasis of lifeEvidence on Mars for a past, wet eraJupiter’s hydrogen and helium atmosphere and its many moonsSaturn’s rings and its moon Titan, which is larger than MercuryUranus and its moons: a system tipped on its side compared to the other planetsNeptune’s largest moon, Triton, with nitrogen “geysers” and a “backward orbit”Pluto as a member of the family of Minor Planets!