* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Solar.System
Circumstellar habitable zone wikipedia , lookup
History of astronomy wikipedia , lookup
History of Mars observation wikipedia , lookup
Tropical year wikipedia , lookup
Nebular hypothesis wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Astronomical unit wikipedia , lookup
Geocentric model wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Extraterrestrial atmosphere wikipedia , lookup
Planetary system wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Exoplanetology wikipedia , lookup
Galilean moons wikipedia , lookup
Astrobiology wikipedia , lookup
Astronomical naming conventions wikipedia , lookup
Extraterrestrial skies wikipedia , lookup
Naming of moons wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
Dwarf planet wikipedia , lookup
Planetary habitability wikipedia , lookup
Extraterrestrial life wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Solar System wikipedia , lookup
Definition of planet wikipedia , lookup
Comparative planetary science wikipedia , lookup
IAU definition of planet wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
The Solar System • 1 star • 9 8 planets • 63 (major) moons • asteroids, comets, meteoroids The Sun • The sun’s energy comes from nuclear fusion (where hydrogen is converted to helium) within its core. This energy is released from the sun in the form of heat and light. • Remember: Stars produce light. Planets reflect light. • A star’s temperature determines its “color.” The coldest stars are red. The hottest stars are blue. The Planets of the Solar System • Planets are categorized according to composition and size. There are two main categories of planets: – Terrestrial small rocky planets (Mercury, Venus, Earth, Mars) – Jovian gas giants (Jupiter, Saturn, Uranus, and Neptune) Characteristics of Small Rocky Planets • • • • • They are made up mostly of rock and metal. They are very heavy. They move slowly in space. They have no rings and few moons (if any). They have a diameter of less than 13,000 km. Mercury • Mercury has a revolution period of 88 days. Mercury has extreme temperature fluctuations, ranging from 800F (daytime) to -270F (nighttime). • Even though it is the closest planet to the sun, Scientists believe there is ICE on Mercury! The ice is protected from the sun’s heat by crater shadows. Venus • Venus is the brightest object in the sky after the sun and moon because its atmosphere reflects sunlight so well. People often mistake it for a star. • Its maximum surface temperature may reach 900F. • Venus has no moons and takes 225 days to complete an orbit. Earth • Earth is the only planet known to support living organisms. • Earth’s surface is composed of 71% water. – Water is necessary for life on Earth. – The oceans help maintain Earth’s stable temperatures. • Earth has one moon and an oxygen rich atmosphere. Earth’s Moon • It takes the moon approximately 29 days to complete one rotation. The same side of the moon always faces us. • The moon’s surface is covered in dust and rocky debris from meteor impacts. It has no water or atmosphere. • The moon reflects light from the sun onto the earth’s surface. Mars • Like Earth, Mars has ice caps at its poles. • Mars has the largest volcano in our solar system: Olympus Mons. Olympus Mons is approximately 15 miles high. • Mars appears red because of iron oxide, or rust, in its soil. • Mars has two moons and takes about two years to complete an orbit. Moons of Mars Phobos Deimos Gouged by a giant impact crater and beaten by thousands of meteorite impacts, Phobos is on a collision course with Mars. It may collide with Mars in 50 million years or break up into a ring. It is also heavily cratered with a small lumpy appearance. Pluto • Pluto has only 5 moons and takes about 249 years to orbit the sun. • Part of Pluto’s orbit passes inside that of Neptune, so at times Neptune is the planet farthest from the sun. • Pluto was located and named in 1930, but today Pluto is no longer considered a planet. Largest is Charon Characteristics of Gas Giants • They are made up mostly of gases (primarily hydrogen & helium). • They are very light for their size. • They move quickly in space. • They have rings and many moons. • They have a diameter of less than 48,000 km Jupiter • Jupiter is the largest and most massive planet. • It’s diameter is 11 times bigger than that of the Earth’s. • It takes about 12 years for Jupiter to orbit the sun. • Jupiter has 63 known moons. Moons of Jupiter 1. Io 2. Europa 3. Ganymede 4. Callisto 5. Amalthea 6. Himalia 7. Elara 8. Pasiphae 9. Sinope 10. Lysithea 11. Carme 12. Ananke 13. Leda 14. Thebe 15. Adrastea 16. Metis 17. Callirrhoe 18. Themisto 19. Megaclite 20. Taygete 21. Chaldene 22. Harpalyke 23. Kalyke 24. Iocaste 25. Erinome 26. Isonoe 27. Praxidike 28. Autonoe 29. Thyone 30. Hermippe 31. Aitne 32. Eurydome 33. Euanthe 34. Euporie 35. Orthosie 36. Sponde 37. Kale 38. Pasithee 39. Hegemone 40. Mneme 41. Aoede 42. Thelxinoe 43. Arche 44. Kallichore 45. Helike 46. Carpo 47. Eukelade 48. Cyllene 49. Kore 50. S/2003 J2 51. S/2003 J3 52. S/2003 J4 53. S/2000 J11 54. S/2000 J5 55. S/2003 J9 56. S/2003 J10 57. S/2003 J12 58. S/2003 J15 59. S/2003 J16 60. S/2003 J17 61. S/2003 J18 62. S/2003 J19 63. S/2003 J23 Saturn • Saturn is composed almost entirely of hydrogen and helium. • Saturn has many rings made of ice. Saturn’s rings are very wide. They extend outward to about 260,000 miles from the surface but are less than 1 mile thick. • Saturn has 60 known moons, some of which orbit inside the rings! • It takes Saturn about 30 years to orbit the sun. Moons of Saturn 1. Mimas 2. Enceladus 3. Tethys 4. Dione 5. Rhea 6. Titan 7. Hyperion 8. Iapetus 9. Erriapus 10. Phoebe 11. Janus 12. Epimetheus 13. Helene 14. Telesto 15. Calypso 16. Kiviuq 17. Atlas 18. Prometheus 19. Pandora 20. Pan 21. Ymir 22. Paaliaq 23. Tarvos 24. Ijiraq 25. Suttungr 26. Mundilfari 27. Albiorix 28. Skathi 29. Siarnaq 30. Thrymr 31. Narvi 32. Methone 33. Pallene 34. Polydeuces 35. Daphnis 36. Aegir 37. Bebhionn 38. Bergelmir 39. Bestla 40. Farbauti 41. Fenrir 42. Fornjot 43. Hati 44. Hyrokkin 45. Kari 46. Loge 47. Skoll 48. Surtur 49. S/2004 S7 50. S/2004 S12 51. S/2004 S13 52. S/2004 S17 53. S/2006 S1 54. S/2006 S3 55. Greip 56. Jarnsaxa 57. Tarqeq 58. S/2007 S2 59. S/2007 S3 60. Anthe Uranus • Uranus is blue in color due to methane gas in its atmosphere. • Uranus has 11 dark rings surrounding it. • Uranus has 27 known moons and takes 84 years to complete one orbit. Moons of Uranus 1. Cordelia 2. Ophelia 3. Bianca 4. Cressida 5. Desdemona 6. Juliet 7. Portia 8. Rosalind 9. Mab 10. Belinda 11. Perdita 12. Puck 13. Cupid 14. Miranda 15. Francisco 16. Ariel 17. Umbriel 18. Titania 19. Oberon 20. Caliban 21. Stephano 22. Trinculo 23. Sycorax 24. Margaret 25. Prospero 26. Setebos 27. Ferdinand BACK | The Solar System | Sun | Mercury | Venus | Earth | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto (Dwarf Planet) | Asteroids | Comets | Meteors, Meteoroids, and Meteorites | End Show | Neptune • Neptune has the fastest winds in the solar system: up to 2,000 km/hr. • Neptune is also blue in color due to methane gas in its atmosphere. • Neptune takes 165 years to orbit the sun and has 13 moons. Planets song Moons of Neptune 1. Triton 2. Nereid 3. Naiad 4. Thalassa 5. Despina 6. Galatea 7. Larissa 8. Proteus 9. Halimede 10. Psamathe 11. Sao 12. Laomedeia 13. Neso BACK | The Solar System | Sun | Mercury | Venus | Earth | Mars | Jupiter | Saturn | Uranus | Neptune | Pluto (Dwarf Planet) | Asteroids | Comets | Meteors, Meteoroids, and Meteorites | End Show | Terrestrial Planets •Mercury, Venus, Earth and Mars •Close to Sun •Small masses, radii •Rocky, solid surfaces •High densities •Slow rotation •Weak magnetic field •No rings •Few moons Jovian Planets •Jupiter, Saturn, Uranus, and Neptune •Far from Sun •Large masses and radii •Gaseous surface •Low densities •Fast rotation •Strong magnetic field •Many rings •Many moons The distances to planets are known from Kepler’s Laws (once calibrated with radar ranging to Venus) How are planet sizes determined? Measure angular size on sky, Then use geometry….. Using angular size to get actual size Masses - determined through observing the gravitational effect of the planet on some nearby object (moons, nearby planets, satellites) Density - divide mass by volume • Planets orbit the sun counterclockwise as seen from the North Celestial Pole. • All planets are in the same orbital plane EXCEPT Mercury and Pluto. Terrestrial planets Jovian planets (and earth) OTHER SOLAR SYSTEM OBJECTS Kuiper Belt Objects • These large, icy objects have orbits similar to the smaller objects in the Kuiper belt that become short period comets. • So are they very large comets or very small planets? Hubble’s View of Pluto and Its Moons Other Kuiper Belt Objects • Most have been discovered very recently so little is known about them. • NASA’s New Horizons mission will study Pluto and a few other Kuiper belt object in a planned flyby. Are Pluto and Eris planets? Pluto and Eris • Pluto’s size was overestimated after its discovery in 1930, and nothing of similar size was discovered for several decades. • Now other large objects have been discovered in Kuiper belt, including Eris. • The International Astronomical Union (IAU) now classifies Pluto and Eris as dwarf planets. • Dwarf planets have not cleared most other objects from their orbital paths. Asteroids - rocks with sizes greater than 100m across Most asteroids remain in the Asteroid belt between Mars and Jupiter but a few have orbits that cross Earth’s path. Three asteroids hit the Earth every 1 million years! Known asteroid impact sites Asteroid sizes range from 100m to about 1000km They are composed of carbon or iron and other rocky material. The Asteroid belt is a group of rocks that appear to have never joined to make a planet. Why do we think this? •Too little mass to be a planet •Asteriods have different chemical compositions It’s all Jupiter’s fault….. Meteoroids – interplanetary rocky material smaller than 100m (down to grain size). •called a meteor as it burns in the Earth’s atmosphere •if it makes it to the ground, it is a meteorite Most meteor showers are the result of the Earth passing through the orbit of a comet which has left debris along its path Meteors are rocky - mainly iron and nickel Some contain carbonaceous material - rich in organic material Meteors are old - 4.5 billion years - based on carbon dating Meteor crater near Winslow, AZ - the culprit was probably 50 m across weighing 200,000 tons! Meteor showers: Orionid – Oct 21/22 Leonid – Nov 18/19 Geminid – Dec 14/15 Comets Dirty snowballs - dust and rock in methane, ammonia and ice All light is reflected from the Sun - the comet makes no light of its own Halley’s Comet in 1986 The nucleus is a few km in diameter •Cometary orbits take them far beyond Pluto •Many take up to 1 million years to orbit the Sun once! •These long period comets probably originate in the Oort cloud •Short period comets (< 200 years) (like Halley’s comet) •Short period comets may have originated in the Kuiper belt •Kuiper belt comet gets “kicked” into an eccentric orbit, bringing it into the solar system Formation of the Solar System Any theory to describe the formation of our Solar System must adhere to these facts: 1. 2. 3. 4. 5. 6. 7. 8. 9. Each planet is isolated in space The orbits are nearly circular The orbits of the planets all lie in roughly the same plane The direction they orbit around the Sun is the same as the Sun’s rotation on its axis The direction most planets rotate on their axes is the same as that for the Sun The direction of a planet’s moon orbits is the same as that planet’s direction of rotation The Terrestrial planets are very different from the Jovian planets Asteroids are different from both types of planets Comets are icy fragments that don’t orbit in the ecliptic plane Nebular Theory for Solar System formation Our sun and the planets began from a cloud of dust and gas (nebula) As the cloud contracts under its own gravity, the Sun is formed at the center. The cloud starts to spin and the smaller it contracts, the faster it spins. Conservation of angular momentum Cloud forms a flattened, pancake shape. We’ve seen these disks around other young stars! Beta Pictoris Conservation of Angular Momentum Angular momentum mass rotation rate radius2 Condensation Theory for Planet Formation The gas in the flattened nebula would never eventually clump together to form planets. Interstellar dust (grain-size particles) lies between stars remnants of old, dead stars. These dust grains form condensation nuclei other atoms attach to them to start the “collapsing” process to form the planets in the gas cloud. What happened next….. A flattened solar nebula disk exists after cloud spins and contracts Condensation nuclei form clumps that grow into moon-size planetesimals Solar wind from star formation (Sun forming) blow out the rest of the gas Planetesimals collide and grow Planetesimals form the basic planets over hundred million years Why the difference between inner and outer planets? TEMPERATURE! •Rocky inner planets: The type of the material that condensed out of the nebular cloud at these higher temperatures was rocky in nature. •Gaseous, Bigger outer planets: Both rock and gas could condense out of the cloud at lower temperatures where these planets formed. Why are they gaseous? - gas is present Why are they bigger? - accretion onto the planet starts sooner because they are further from the Sun, less effected by solar wind