Transcript The Sun
Section 3.2 (Astronomy book) • Vocabulary to know: • • • • • • Corona Chromosphere Photosphere Convective zone Radiative zone Nuclear fusion – Hydrogen – Helium • Sunspot • Solar flare The Sun • What makes the sun so important? • Why is it so darn hot? • Could there be life on Earth without the sun? Sun Anatomy • Core- where nuclear fusion takes place. • Radiation zoneenergy absorbed and then reradiated. • Convection zoneenergy transferred outward by convective currents. Sun Anatomy • Photosphereinnermost layer of atmosphere (9,980 degrees F) • Chromospheremiddle layer of atmosphere (17,540 degrees F) • Coronaoutermost layer (1,799,540 degrees F) Energy From the Sun • The sun’s energy is produced in it’s central region by the fusion of Hydrogen nuclei into Helium nuclei. – Temperature and pressure extremely high…that’s why fusion takes place. • Smaller nuclei combine to form bigger nuclei releasing lots of energy. Hydrogen Bomb • It’s power comes from fission-fusion-fission… • In other words: splitting of atoms/nucleicombining atoms/nucleisplitting of atoms/nuclei • We may soon be able to do fusion reactions and not have to worry about an electricity shortage. Stars • Is the sun a star? • What is a star? – Star- large, glowing ball of gas in space, which generates energy through nuclear fusion in its core. • Could we travel to the next closest star? Proxima Centauri • The next closest star is Proxima Centauri. – About 4.2 light years away. • Light travels 5.88 trillion miles in a year. • How do we know this? • How can we measure the distance to this star? • Have we sent satellites this far? Section 3.1 (Weather and Climate Book) • Vocabulary to know: • • • • • • • • • • • • • Weather Climate Rotation Revolution Latitude Longitude Tropic zone Temperate zone Polar zone Solar energy Summer solstice Winter solstice Greenhouse effect Weather Vs. Climate • Weather • Climate Earth’s Movement • Rotation- the spinning of Earth on it’s axis. – Causes night and day – Takes about 24 hours • Revolution- the movement of Earth in space around the sun. – Takes about 365.25 days Longitude vs. Latitude • Longitude- lines that run vertically on the globe. – Prime meridian- 0 degrees on the globe. • Runs through the Eastern portion of Africa. Latitude vs. Longitude • Latitude- lines that run horizontally on the globe. – Equator- 0 degrees on the globe. • Latitude lines are used to mark out 3 different types of regions – Tropic – Temperate – Polar Tropic Zone • Tropic- between the latitudes of 23.5 degrees north (Tropic of Cancer) and 23.5 degrees south (Tropic of Capricorn). – Generally hot temperature. – Sun’s rays hit Earth directly at the equator. Temperate Zone • Temperatebetween the latitudes 23.5 degrees and 66.5 degrees. – Generally cooler than the Tropics. – The USA is in a Temperate zone. Polar Zone The Seasons • The seasons are caused by the tilt of Earth’s axis as it moves around the sun. • The Earth is tilted at 23.5 degrees. • (Take Notes) • Solstice- occurs when sun is directly overhead at latitudes 23.5 degrees north or south. – Summer solsticeJune 21 in the Northern hemisphere. • Beginning of summer. – Winter solsticeDecember 21 in the Northern hemisphere. • Beginning of winter. The Seasons • Equinox- neither hemisphere is tilted towards the sun. – The lengths of daylight and darkness are approximately equal. – Vernal equinoxMarch 21 in the Northern hemisphere. – Fall equinox- Sept 22 in the Northern hemisphere. The Seasons • Incoming solar energy: – 30% reflected back into space by clouds, gases, and Earth’s surface. – 20% absorbed by clouds. – 50% absorbed by Earth’s surface. • Heats up the Earth.