Space Exploration with James Paradise Sept, 2006 Solar System Quiz 1. What is the closest star to Earth? 2. How many planets are there in our solar system? 3. What is the smallest planet in our solar system? 4. What is the most distant planet from the Sun? 5. In what galaxy is our solar system located? 13.Other than Earth, where else might life exist in our solar system? 1. What is the closest star to Earth? 1. What is the closest star to Earth? The nearest star to Earth is the one we see every day - our Sun. At a mere 93 million miles distant, it takes light from the Sun only eight minutes to arrive on Earth. The next closest are three members of Alpha Centauri and are just over 4 light years from Earth. There are 10 star systems located within 12 light years of E arth. 2. How many planets are there in our solar system? 1. How many planets are there in our solar system? Currently: 8 planets Since 1930, we have been looking for Planet X More recent Pluto news: • 1978: Pluto’s moon Charon discovered • 2005: Two more Pluto moons? (Charon, Nix and Hydra) • 2006: Pluto demoted from planet to Dwarf Planet Quaoar 2000 - 2002: Varuna, Ixion, and Quaoar discovered Astronomers have discovered super-size balls of ice and rock — half the size of the planet Pluto — lurking roughly 4 billion miles from the Sun at the edge of our solar system. A year on Quaoar takes 286 Earth years. It follows a circular orbit around the sun and has a temperature of minus 381 degrees Fahrenheit. "If Pluto deserves to be a planet, then I would think that Quaoar does too," says astronomer Alan Boss of the Carnegie Institution in Washington, D.C. Orbit: 280 - 300 years Orbit Shape: Circular Distance from Sun: 4 billion miles P luto distance: 3 billion miles Sedna 2003: Sedna discovered NASA-funded researchers have discovered the most distant object orbiting Earth's Sun. The object is a mysterious planet-like body three times farther from Earth than Pluto. The object, named "Sedna" for the Inuit goddess of the ocean, is 8 billion miles from the Sun. Sedna is in a region of our solar system, Orbit: 10,500 years where temperatures never rise above minus Orbit Shape: Highly Eliptical 400 degrees Fahrenheit. Closest point: 8 billion miles Fartheset point: 84 billion miles 2003: IAU rules Ixion, Varuna, Quaoar, and Sedna are not planets, and suggests Pluto distance: 3 billion miles that size of Pluto will be minimum size for Quaoar distance: 4 billion miles planets. Where is Sedna’s Orbit? Where is Sedna’s Orbit? Our inner so lar system Where is Sedna’s Orbit? (zooming out: square in middle is previous screen) How find planets? How do we find planets? Telescope photo of a region in space. Planets move too slowly to be spotted in a single image!! Did any dots move? Photo 1 Photo 2 (90 min later) Photo 3 (90 min later yet) Moving dot is circled in each image! Photo 1 Photo 2 (90 min later) Photo 3 (90 min later) Now overlay All 3 photos overlaid onto each other. The new object, circled in white, moves across a field of stars on Oct. 21, 2003. The three photos were taken about 90 minutes apart. The object was discovered by the Samuel Oschin Telescope at the Palomar Observatory on Jan . 8, 2005. January 8, 2005: Planet X discovered? (10th planet?) This artist's concept shows the object catalogued as 2003UB313 at the lonely outer fringes of our solar system, nick-named Xena. Orbit: 557 years Orbit Shape: Highly Eliptical Distance from Sun: 7.3 billion miles Relative Size of Xena Eris 2006: IAU meets to define “planet” and vote: • Definition 1: Xena, Ceres, and Charon all become planets • Definition 2: Demote Pluto and lock number of planets at 8 IAU Decision: • Pluto demoted, now designated 134340 Pluto • 2003 UB_313 named Eris and its satelite named Dysnomia • Pluto, Eris, and Ceres declared Dwarf Planets • Quaoar, Sedna, Ixion, and Varuna expected to become Dwarf Planets Definition of a Planet IAU Resolution: Definition of a Planet in the Solar System Contemporary observations are changing our understanding of planetary systems, and it is important that our nomenclature for objects reflect our current understanding. This applies, in particular, to the designation 'planets'. The word 'planet' originally described 'wanderers' that were known only as moving lights in the sky. Recent discoveries lead us to create a new definition, which we can make using currently available scientific information. RESOLUTION 5A, August 24, 2006: The IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way: (1) A "planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit. Note: The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. (2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite. Note: An IAU process will be established to assign borderline objects into either dwarf planet and other categories. (3) All other objects except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies". Note: These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies. 3. What is the smallest planet in our solar system? 3. What is the smallest planet in our solar system? OfficiaPllayn, Met/Oerbcjeucrty (since DPliuatmo iest neor l(omniglers a) planet) Quaoar 800 Sedna 1,000 Pluto 1,400 Xena 1,600 – 1,800 Mercury 3,050 Mars 4,220 Venus 7,500 Earth 7,920 Neptune 30,200 Uranus 31,500 Saturn 74,500 Jupiter 88,700 3. What is the smallest planet in our solar system? Pluto (assuming Pluto is actually a planet) Sun, 8 current planets, and pluto shown in correct scale 4. What is the most distant planet from the Sun? 4. What is the most distant planet from the Sun? Neptune From 1979 until 1999, Neptune was the farthest planet from the sun. In 1999, Pluto became the furthest planet from the Sun. With Pluto demoted in 2006, now Neptune will always be the most distant planet. 5. In what galaxy is our solar system located? 5. In what galaxy is our solar system located? The Milky Way is a thin disk containing an estimated 200 billion to 700 billion stars We lie in a spiral band called the Orion-Cygnus arm which is made up of the collection of younger and middle-aged stars. Our Solar System is located about 27,000 light-years from galactic center and 20,000 light-years from the outer edge. Milky Way Galaxy 6. Other than Earth, where else might life exist in our solar system? Follow the water 6. Other than Earth, where else might life exist in our solar system? NASA's strategy Location of liquid / frozen water Remarks Jupiter’s moons: Galileo discovered strong evidence of is to "follow the Europa liquid salt water oceans beneath an ice Ganymede layer on three of Jupiter’s moons. water" in the Callisto Saturn’s moon: Casini, a twin to Galileo, has found search for life. Enceladus evidence of liquid salt water ocean beneath an ice layer on Saturn’s moon, Enceladus. Earth’s moon Clementine and lunar Prospector robotic spacecraft each found evidence of water ice in permanently shaded areas near its poles. Mars Mars Global Surveyor and Mars Odyssey have each found evidence of water ice at Mars poles and within 2 meters of the surface across much of the planet. Planetary Rings: All four gas giant planets have rings that Jupiter are rich in water ice. Saturn Uranus Neptune Comets Comet’s primary constituent is water ice. Asteroids Asteroid Ceres is very primitive and wet and may have a thin, permanent Next: V ostok atmosphere. A Jupiter Icey Moons Orbiter will one day orbit up to 3 of Jupiter’s moons to confirm the presence or absence of an ocean. Other possible missions could include a Lander, a Penetrator, and Hydrobots. Europa is very similar to Lake Vostok, discovered under the Antarctic ice in 1974. Update on Manned Missions Old: Space Shuttle to New LM CEV to be retire by 2010 operational by 2014 CEV on Atlas V Launch Vehicle (Atlas V is candidate CLV) CEV terra landing w air bags International Space Station (ISS) NASA’s Top Priority: Complete the International Space Station by 2010. See the Space Station fly over Denver http://spaceflight1.nasa.gov/realdata/sightings/cities/index.cgi Current and Recent Unmanned Robotic Missions A few of the Denver missions from the past 34 years We are currently flying 4 spac ecraft from here in Denver. Mars Global Surveyor Mars Mapping Mission Launch: 11/7/1996 Arrive: 9/11/97 Status: Still actively mapping This orbiter has studied the entire Martian surface, atmosphere and interior, and has returned more data about the red planet than all other Mars missions combined. Among key science findings so far, Global Surveyor has taken pictures of gullies and debris flow features that suggest there may be current sources of liquid water, similar to an aquifer, at or near the surface of the planet.