Earth Science Midterms

• The Solar System is a collection of planets, moons, asteroids, comets, and other rocky objects travelling in elliptical orbits around the sun under the influence of its gravity
• The sun is 4.5 billion year old star and the center of the solar system.
• A sun is a hot, glowing ball of hydrogen and helium.
• Life without the sun's energy is impossible.
• Sun is around 93 millions miles from Earth.
• The sun is approximately 100 times larger than Earth and approximately 10 times larger than Jupiter.
• Sun's core temperature is approximately 15 million degree celsius.
• The four terrestrial planets are venus, earth, mercury, & mars (vemm).
• Four terrestrial planet - the high temperature close to the sun permitted only those compounds with high condensation temperatures to remain solid, gradually accreting (sticking together) particles.
• The gas giants/jovian planets are jupiter, uranus, neptune, & saturn (juns).
• Gas giants are formed from cores of the rock and metal and an abundance of ice.
• Gas giants with the huge quantity of ice they became large and produce strong gravitational fields that captured the slow - moving hydrogen and helium
• Further out from the sun, beyond neptune, is the kuiper belt.
• Kuiper belt is like the asteroid belt but much larger; it is the source of short - period comets and contains dwarf planets (Pluto)
• Oort cloud is a collection of icy debris and it is in the edge of solar system.
• Six of the planets have moons orbiting them; Jupiter, Uranus, Saturn, Mars, Earth, Neptune (jusmen).
• Jupiter - Ganymede, Europa, Io, Callisto Uranus - Titanis, Oberon, Umbriel, Ariel, Miranda, Pick Saturn - Enceladus & Titan Mars - Phobos & Deimos Earth - Moon Neptune - Triton, Proteus, Nereid, Larissa, Galatea, Despina
• Asteroids are rocky objects orbiting the sun - they are millions of them contained in solar orbit in the asteroid belt situated between Mars and Jupiter.
• Comets are irregular objects a few kilometers across comprising frozen gases, rock & dust.
• Observable comets travel around the sun in sharply elliptical orbits raging from a few years to thousand of years.
• As comets draw near to the sun the gases in them are vaporized, forming a distinct comet tail that is very long and points away from the sun.
• Stars are initially form when gravity causes the gas in a nebula to condense.
• Binary stars consist of two stars that rotate about a common center of mass.
• Stellar cluster are a group of stars that are positioned closely enough to be held together by the gravity.
• Constellation is a pattern formed by stars that are in the same general direction when viewed from the earth.
• Meteor showers are named for the constellation where the meteors appear to be coming from
• Orionids meteor shower occurs in october, appears to come from the same direction of the constellation Orion the Hunter.
• Nebulae is a regions of intergalactic cloud of dust and gas
• The singular term for nebulae is nebula.
• All stars born out of nebulae is called stellar nurseries.
• First origin of nebulae - occurred in the matter era around 380000 years after big bang
• Second origin of nebulae - is from the matter that has been ejected from supernova explosion
• Galaxy is a creation of stars, gas, & dust held together by gravity and containing billions of stars.
• Spiral galaxies have disc shape with spiral arms spreading out from a central galactic bulge that have the greatest density of stars.
• The elliptical galaxy has an ellipsoidal shape and a smooth, nearly featureless image.
• Irregular galaxy does not have a distinct regular shape
• Parallax is the observed apparent change in the position of an object resulting from a change in the position of the observer.
• The difference between luminosity and apparent brightness depends on distance.
• Luminosity of a star is the amount of light it emits from surface.
• Apparent brightness is how bright the star appears to a detector here on earth