Astronomy = the study of the universe

Astro = starCentr = centerGeo = earthRetro = backPre = beforePeri = aroundMar = oceanTerre = groundSol = sunChrom = colorpro = first

Astronomical History!

• Geocentric Model = moon, sun and planets orbit Earth.

Astronomical History!

• Heliocentric Model = Earth and other planets orbit sun.

Astronomical History!

• Ptolemaic System = Planets orbit Earth, but seemed to exhibit retrograde motion.

Astronomical History!Copernicus:

Earth is a planet that

orbits the sun.

Brahe: Yes, but my observations are much more

precise.

Kepler: No, my 3 laws of planetary

motion prove that Brahe is

wrong.

Galileo: Well, here is how the planets and their satellites

move.

Newton: The planets are held

into a circle by the gravity of the sun.

Earth – Moon - Sun

Rotation = spinningRevolution = going around another object

Earth Rotating http://svs.gsfc.nasa.gov/vis/a000000/a001300/a001374/index.html

Perihelion Aphelion

CLOSEST FARTHEST

SEASONS

Plane of the Ecliptic = reference plane that runs from pole to pole.

Plane is tilted about 23.5o.

Seasons are result of the tilt.

More Earth Movement

Precession = very slow wobbling

http://earthobservatory.nasa.gov/Features/Milankovitch/Images/milankovitch_precess_high.mov

Earth - Moon

Perigee = moon is closest to earthApogee = moon is farthest from earth

Phases of the Moon

http://videos.howstuffworks.com/hsw/10001-the-moon-phases-video.htm

NAME THAT PHASE!

ECLIPSE

Solar eclipse = moon is between earth and sun (like the background here!) and casts a shadow on Earth.Lunar eclipse = Earth moves between sun and moon and casts shadow on moon.

Man on the Moon

http://news.sky.com/skynews/Home/World-News/Nasa-Releases-Footage-Of-Moon-Landing-When-Astronaut-Neil-Armstong-Took-First-Steps-On-July-20-1969/Article/200907315338603

Earth’s Moon

• The Only Natural Satellite• 1/4th diameter of Earth• Apollo moon mission 1969-1972

• Gravity 1/6th that of Earth• 150 lb person = 25 lbs

Craters • round depressions• produced by impacts

Impact by meteor. Compresses surface material.

Rebound splash of ejecta. Uplift of deep rock in center.

Major Topographic features of the Moon:

Highlands = light colored areas (almost as high as Mt. Everest!)Mare (Maria, pl.) = dark smooth areas (ancient beds of lava)

Rilles are valleys or trenches.Regolith = soil-like layer

Lunar History

When solar system was forming, a body the size of Mars impacted Earth and the debris shot into space. One piece was our Moon.

How the Moon Formed http://videos.howstuffworks.com/hsw/9998-the-moon-formation-video.htm

The Solar System

Terrestrial Planet = small and rocky (inner planets)Jovian Planet = large gaseous (outer planets)

http://player.discoveryeducation.com/index.cfm?guidAssetId=21B610C4-B1BB-40E0-8760-825A41B19E12&blnFromSearch=1&productcode=US

Nebular Theory = sun and planets formed from a rotating disk of dust and gases.

Planetesimals = small, irregular-shaped bodies that collided and clumped together to form the planets.

Formation of the Solar System

Asteroids = small, rocky bodies floating in space(Largest, Ceres, is about 1000 km in diameter!)

Comets = pieces of rocky and metallic materials held togetherby frozen gases like water, ammonia, methane, etc.

(Some take hundreds of thousands of years to make one orbit.)

Small Pieces (w/Quiz) http://player.discoveryeducation.com/index.cfm?guidAssetId=BD722E4D-32D2-4342-B475-F031BFDC4EEC&blnFromSearch=1&productcode=US

Coma = the glowing head of a comet produced when the sun begins vaporizing the comet’s frozen gases.Tail = stream of glowing vaporizing gases

Halley’s Comet76-yr-orbit

Kuiper Belt = disc-shaped region beyond Neptune where short-orbital comets originate.

Oort Cloud = area spreading in all directions from the sun where long-orbital comets originate.

METEORS!Meteoroid

• small, solid particle• travels through space• origination• interplanetary debris• asteroid belt material• remains of comets

Meteor

• meteoroid that enters Earth’s atmosphere• Meteor Shower = a group of meteors traveling in the same direction

Meteor in Peru 2007 http://news.bbc.co.uk/player/nol/newsid_7000000/newsid_7002300/7002376.stm?bw=bb&mp=wm&asb=1&news=1&ms3=54&ms_javascript=true&bbcws=2

The SUNPhotosphere = visible surface (90% hydrogen)

Chromosphere = thin layer of hot gases (can see during solar eclipse)

Corona = weak outermost layer (extends 1 million km)

Solar wind = streams of protons and electrons

Convective Zone

Radiative Zone

Core

Photosphere

Chromosphere

Corona

Earth

Activity of the Sun:

Sunspots = appear dark because they are cooler than the rest of the sun. http://www.windows.ucar.edu/tour/link=/sun/atmosphere/

sun_rotate_anim_jan2005.html&edu=high

Prominences = large cloudlike structures consisting of chromospheric gases.

Solar Flares

• explosive events• last about an hour• sudden brightening above a sunspot cluster• release enormous amounts of energy• ejects atomic particles• produce auroras (northern lights)

http://images.google.com/imgres?imgurl=http://earthobservatory.nasa.gov/images/imagerecords/3000/3912/flare_soh_2003301.jpg&imgrefurl=http://earthobservatory.nasa.gov/IOTD/view.php%3Fid%3D3912&usg=__1KWUaN-ZdTALrPPKRSxiynbT1xU=&h=865&w=540&sz=74&hl=en&start=3&um=1&itbs=1&tbnid=jLzIYZNVqdx_VM:&tbnh=145&tbnw=91&prev=/images%3Fq%3Dsolar%2Bflare%2Banimation%26ndsp%3D20%26hl%3Den%26safe%3Dactive%26rls%3Dcom.microsoft:en-us%26um%3D1

http://images.google.com/imgres?imgurl=http://veimages.gsfc.nasa.gov/10194/a001168_pre.jpg&imgrefurl=http://visibleearth.nasa.gov/view_rec.php%3Fid%3D10194&usg=__0rK1487FipNjvZgrwD7bE1yTeO8=&h=242&w=320&sz=7&hl=en&start=13&um=1&itbs=1&tbnid=rfP8CkCb5ln2KM:&tbnh=89&tbnw=118&prev=/images%3Fq%3Dsolar%2Bflare%2Banimation%26ndsp%3D20%26hl%3Den%26safe%3Dactive%26rls%3Dcom.microsoft:en-us%26um%3D1

It’s how far??!!

1 Light Year = how far light travels in one year. Light travels at 299,792,458 m/s so in one year light goes 5.88 trillion (5.88 × 1012) miles.

1 A.U. (Astronomical Unit) is the distance from the Earth to the Sun which is 150 million km (93 million miles).

Earth’s diameter = 7,926 miles

  

   

ANTARES IS THE 15TH BRIGHTEST STAR IN THE SKY. IT IS MORE THAN 1000 LIGHT YEARS AWAY. THIS IS A HUBBLE TELESCOPE ULTRA DEEP FIELD INFRARED VIEW OF COUNTLESS 'ENTIRE' GALAXIES BILLIONS OF LIGHT-YEARS AWAY. BELOW IS A CLOSE UP OF ONE OF THE DARKEST REGIONS OF THE PHOTO ABOVE.

   

Sun’s diameter = 870,000 miles

Sirius is the brightest star in the night-time sky. It is located in the constellation Canis Major. It is 8.5 light years away. Pollux is 33.7 light years away. Arcturus is 36.7 light years away.

ANTARES IS THE 15TH BRIGHTEST STAR IN THE SKY. IT IS MORE THAN 1000 LIGHT YEARS AWAY.