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INTRODUCTION TO ASTRONOMY. Overview FRONTIERS IN ASTRONOMY PHYS 271. North America. Landsat Satellite Images. Earth from SPACE. APOLLO 17 IMAGE. Earth and Moon. From Galileo Spacecraft on way to Jupiter. Comparison of Earth and Moon. Relative Diameters
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INTRODUCTION TO ASTRONOMY Overview FRONTIERS IN ASTRONOMY PHYS 271
North America • Landsat Satellite Images
Earth from SPACE • APOLLO 17 IMAGE
Earth and Moon • From Galileo Spacecraft on way to Jupiter
Comparison of Earth and Moon • Relative Diameters • Earth ~ 8000 miles, Moon ~ 2160 miles
Distance to the Moon • About 240,000 miles (similar to the Diameter of Saturn’s Rings)
The Moon • Mare Orientale: a large lunar crater on the East Limb (edge). ~ 700 miles Diameter
The Sun • Much larger than the Planets
The Sun • The Chromosphere with a large Prominence (~ 864,000 miles in Diameter)
The Corona in X-Rays • Active regions (solar activity)
The Astronomical Unit • Average distance between Sun and Earth • ~ 150 million Kilometers or 93 million miles
Size of the Sun • 109 times the diameter of Earth
Relative Size of the Planets • Pluto smaller than the Moon
Orbits of the Planets • Eccentricity and inclination of Pluto’s Orbit!
The Sky – Celestial Sphere • North and South Celestial Poles • The Celestial Equator
Rotation or Spin • Rotation of the Earth - time scale Day • 24 hours with respect to the Sun
Rotation of SKY – Star Trails • 23 hours and 56 minutes, diurnal motion
Diurnal Motion Near Horizon • Western or Eastern Horizon
Circumpolar Stars or constellations • They never set, 23 hours 56 minute clock
Revolution • The orbit of the Earth (sky changes)
Constellations • Chance alignments in different directions
Summer Triangle • Looking in different directions from Sun
Winter Constellations • Use your imagination – anthropomorphic
Stars very far away • Pleiades (A star cluster size of full Moon)
Milky Way – Our Galaxy • Looking toward Andromeda Nebula
About 200 billion stars • Some close, some intermediate, some far
Andromeda Galaxy • Nearest Major Galaxy – • 2.7 million Light Years distant
Clusters of Galaxies • 100s or 1000s of individual galaxies!
Giant Elliptical GalaxyStandard Candles • Dominates Centers of most Clusters • Among Brightness Objects we know
Clusters more and more remote • Billions of light years distant
Hubble Deep Field • Smallest blue objects more than 10 billion light years distant