Astronomy Notes Page 4 The Universe ©Mark Place, 2009-2010 www.LearnEarthScience.com

Big Bang Animation

What did the Big Bang sound like? Forget the big bang, tune in to the big hum THE big bang sounded more like a deep hum than a bang, according to an analysis of the radiation left over from the cataclysm. Physicist John Cramer of the University of Washington in Seattle has created audio files of the event which can be played on a PC. "The sound is rather like a large jet plane flying 100 feet above your house in the middle of the night," he says. Giant sound waves propagated through the blazing hot matter that filled the universe shortly after the big bang. These squeezed and stretched matter, heating the compressed regions and cooling the rarefied ones. Even though the universe has been expanding and cooling ever since, the sound waves have left their imprint as temperature variations on the afterglow of the big bang fireball, the so-called cosmic microwave background. Cramer was prompted to recreate the din- last heard13.7 billion years ago- by an11-year-old boy who wanted to know what the big bang sounded like for a school project. To produce the sound, Cramer took data from NASA's Wilkinson Microwave Anisotropy Probe. Launched in 2001, the probe has been measuring tiny differences in the temperature between different parts of the sky. From these variations, he could calculate the frequencies of the sound waves propagating through the universe during its first 760,000 years, when it was just 18 million light years across. At that time the sound waves were too low in frequency to be audible. To hear them, Cramer had to scale the frequencies 100,000 billion billion times. Nevertheless, the loudness and pitch of the sound waves reflect what happened in the early universe. During the 100-second recording (http://www.npl.washington.edu/AV/BigBangSound_2.wav), the frequencies fall because the sound waves get stretched as the universe expands. "It becomes more of a bass instrument," says Cramer. ### Author: Marcus Chown

What is the Big Bang Theory? The universe started as a single point. That point was extremely dense. It became unstable and exploded outward. Today the universe continues to expand.

The Doppler Effect

Evidence for the Big Bang light from distance galaxies all shift toward red

Shifts in the Electromagnetic Spectrum Red Shift = away Blue Shift = toward

Evidence for the Big Bang Cosmic Background Radiation

galaxy solar system universe Put these in order of size: galaxy solar system universe universe galaxy solar system Largest Smallest

Stars Astronomy Notes Page 5 ©Mark Place, 2009-2010 www.LearnEarthScience.com

What are the main classifications of stars? Blue Supergiants Red Giants Main Sequence White Dwarfs Red Dwarfs ESRTs p15

characteristics are used to What two characteristics are used to classify stars? Luminosity Temperature ESRTs p15

What type of star is our Sun classified as? Main Sequence ESRTs p15 Main Sequence Circle where it is on the chart

Shade the chart where all of the stars are hotter than our sun. Draw a line on the chart which separates those stars brighter than our sun and those less bright. ESRTs p15

What color are the stars in the constellation Orion? Red Blue Betelgeuse is Red What color are the stars in the constellation Orion? Rigel is Blue ESRTs p15

How do stars generate their energy? Hydrogen Helium Hydrogen Nuclear Fusion

Our Solar System ©Mark Place, 2009-2010 www.LearnEarthScience.com

The total mass of all the asteroids is less than that of the Moon. rocky objects with round or irregular shapes lie in a belt between Mars and Jupiter The total mass of all the asteroids is less than that of the Moon.

only visible when they are close to the sun

shooting stars

The Planets

Draw a line across the table between the terrestrial and jovian planets and label.

Which are more dense? Jovian or terrestrial

Which have more moons ? Jovian or terrestrial

Which have longer periods of revolution? Jovian or terrestrial

Which are larger in size on average ? Jovian or terrestrial

Which planet has the longest day? Venus

Which planet has the longest year? Neptune

How are the orbits of the planets described? slightly, eccentric ellipse eccentricity website

Which planet has the least perfectly circular orbit? Mercury

Which planet has the most perfectly circular orbit? Venus

Calculate the eccentricity of the ellipse below: length of major axis Formula: eccentricity = distance between foci length of major axis

When does a planet move slowest in its orbit? When furthest from Sun When does a planet move fastest in its orbit? When closest to Sun

Kepler's Second Law Area A = Area B Area C eccentricity website

Explain the difference between the geo- and helio-centric models of the solar system. Helio-centric Geo-centric Earth- centered Sun- centered

Earth Motions Astronomy Page 8 ©Mark Place, 2009-2010 www.LearnEarthScience.com

How long is one rotation of Earth? Earth's Motions How long is one rotation of Earth? One day How long is one revolution of Earth? One year

Movement of Stars through the sky Rising and Setting Rotation of the Sun Rotation Rising and Setting of the Moon Movement of Stars through the sky Revolution Changing Constellations The Seasons

Earth's rate of rotation? How do you calculate Earth's rate of rotation? One rotation = 360° Time for one rotation = 24 hours 360° ÷ 24 = 15°/hr

How many degrees did the stars move from diagram 1 to diagram 2? 30° (2 hours x 15°)

It’s the only one that didn’t move How can you find Polaris? It’s the only one that didn’t move

Because Polaris can only been seen in the North What hemisphere must you be in? Why? Northern Because Polaris can only been seen in the North

What direction must you be looking? North

What direction do the stars appear to move?

What causes the stars appear to move?

Evidence for Rotation Foucault Pendulum Coriolis Effect

Evidence for Revolution Changing Constellations Parallax

The Moon Astronomy Page 9 ©Mark Place, 2009-2010 www.LearnEarthScience.com

Why is Earth not like this? Why so many? Craters What are these? No atmosphere Why is Earth not like this? weathering, erosion, atmosphere

Phases of the Moon Astronomy Page 10

What causes the phases of the moon? The moon's revolution around Earth.

27.3 days How long does one revolution of the moon take? How long does one rotation of the moon take? ESRTs p15

What phenomenon does this explain? We only ever see one side of the moon.

Why does the moon rise later each day? because as the Earth rotates, the moon revolves

What phase of the moon is this? New Gibbous New Crescent 3rd Quarter

Approximate Times of Moonrise and Moonset    moonrise    moonset new moon 06:00 AM 06:00 PM waxing crescent 09:00 AM 09:00 PM first quarter 12:00 PM 12:00 AM waxing gibbous 03:00 PM 03:00 AM full moon waning gibbous third quarter waning crescent How many hours is the moon visible each day? 12 hours

What is "waxing"? more of the moon's surface can be seen

What is "waning"? less of the moon's surface can be seen

The phases of the moon are what type of event? Cyclic

Going to the Moon

Great food but no atmosphere! Restaurant on the Moon. Great food but no atmosphere!

Tides & Eclipses Astronomy Page 12 ©Mark Place, 2009-20010 www.LearnEarthScience.com

Tides

What causes tides?

Caused by the gravitational pull of the moon & sun

which types of tides have a larger range? Based on the diagram, which types of tides have a larger range? SPRING TIDES

During which phases of the moon do neap and spring tides occur?

1st & 3rd Quarters Neap?

New or Full Moon Spring?

How many tides a day? 2 high tides 2 low tides

solar and lunar eclipses? What’s the difference between solar and lunar eclipses? Solar Lunar moon goes into Earth’s shadow Earth goes into moon’s shadow

Solar Eclipse 2010

Solar Eclipses through 2020

Lunar Eclipse 2010

solar and lunar eclipses Why don’t we have solar and lunar eclipses every month? The moon’s orbit is tilted 5° from the Earth’s orbit.