chapter 1 orbits. earth and the moon in space o the earth and the moon create a system together. o...

Chapter 1Orbits

Earth and the Moon in Space

oThe Earth and the moon create a system together.

oThey revolve, or travel in a closed path, around the sun.

oWe call Earth’s path an orbit.

Earth and the Moon in Space

oEarth’s orbit is an ellipse.

Earth’s Rotation

oEarth also rotates, or spins on its axis.

oThe axis is an imaginary line passing through the center of Earth’s north and south poles.

Earth’s Rotation

The Moon’s Revolution

oThe moon revolves around the Earth in an ellipse-shaped orbit because of gravity.

oRemember: The universal law of gravitation: all objects in the universe are attracted to all other objects in the universe.

The Moon’s Rotation

oThe moon also rotates along its axis.

oIt takes 27.3 days for the moon to complete one rotation on its axis.

The Moon’s Rotation

oThe same side of the moon always faces Earth because it takes as long to orbit the Earth as it does for it to rotate on its axis.

The Moon’s “Light”

oThe moon does not give off light; it reflects sunlight from its surface.

oAs its position in the sky changes, we see different phases of the moon.

Chapter 1The Seasons

The Seasons

oWe split the year into four seasons: winter, spring, summer, and fall.

The Seasons

oAs the Earth orbits the sun, the amount of sunlight shining on each place changes slightly.

oThis causes the seasons.

Earth’s Tilt

Earth’s Tilt

oThe Earth is tilted at 23.5 degrees.

oFor half the year, the North is pointed more toward the sun, creating longer days with more sunlight.

oDuring this time, the Southern hemisphere has shorter days with less sunlight.

Earth’s Tilt

oThe seasons are opposite on the Northern and Southern hemispheres.

oDuring the summer, the sunlight shines more directly on the surface of Earth, creating higher temps.

Earth’s Tilt

oDuring the winter, the sun hits Earth’s surface at an angle, creating less heat.

The Length of the Day

oIn the Northern hemisphere, June 21st is the longest day and December 21st is the shortest day.

o March 21st (spring equinox) and September 21st (autumn equinox) have an equal amount of day and night.

Chapter 1The Moon’s Features

The Moon’s Surface

oThe surface formed from hot, molten rock that turned into a rocky crust when it cooled.

oThe moon’s has three main features.

Highlands

oAreas of crust that are higher than the surrounding area; almost like a mountain.

Craters

oThe moon has several large and small craters.

oTycho is 54 miles across.

Maria

o“Maria” means “sea”

oDark, flat areas made of hardened lava – basalt rocks.

oThe largest mare is 775 miles across.

Earth and Moon

oBoth rocky and dense.

oBoth have craters, but the moon has more because meteorites burn as they enter Earth’s atmosphere.

Earth vs. Moon

oThe moon has no atmosphere and no liquid water, but frozen water has recently been found.

oNo erosion can occur by wind or water.

Chapter 1The Moon’s Phases

The Phases

oThere are 8 phases of the moon that we see throughout its 27.3 day cycle.

1. The New Moon

oThe moon is between the Earth and the sun.

oIt cannot be seen due to its position.

2. Waxing Crescent

oThe moon is between the Earth and the sun.

oIt cannot be seen due to its position.

3. First Quarter

oThe moon is one quarter of the way around Earth. oLooks like a half circle. oOne week into cycle.

4. Waxing Gibbous

oMore of the sun’s light is reflecting off of the Earth’s surface.

5. Full Moon

oAbout two weeks into cycle, we see the entire sunlit part of the moon.

6. Waning Gibbous

oThe moon is getting slightly “smaller” (less sun light is reflecting).

7. Last Quarter

oAbout three weeks into cycle. oThe moon is three-fourths of the way around Earth.

8. Waning Crescent

oThe moon’s sunlit part is about to disappear. oThe moon’s cycle is almost complete.

The Moon’s Phases

Chapter 1Solar and Lunar Eclipses

What is an eclipse?

oEclipse: when one object passes through the shadow of another.

oEclipses can occur during a new moon or a full moon when the sun, the Earth, and the moon all line up.

Solar eclipses

oOccurs when Earth passes through a new moon’s shadow.

oThe moon completely covers the sun.

oOnly the sun’s outer atmosphere is visible.

Solar eclipses

Lunar eclipses

oOccurs when the full moon passes through the Earth’s shadow.

oThe Earth blocks the sun’s light.

oMakes the moon appear to be red.

Lunar eclipses

Solar vs. Lunar Solar

oNew moon

oSun – moon – Earth

oMoon has light around it.

Lunar oFull moon

oSun – Earth – moon

oMoon appears to be red.

Eclipses

oOnly 7 eclipses (2 lunar and 5 solar) happen throughout the year.

oMost of these are only partial eclipses.

Exploring SpaceTechnology and Time

Exploring the Solar System oThousands of years ago, people could only make observations using their eyes.

o They could see the phases of the moon and the moon’s larger features, but they did not have the technology to research further.

The Telescope o invented about 400 years ago

o Allowed people to see objects in space in greater detail

o an instrument that magnifies (makes larger) distant objects.

The Telescope o First used by an Italian scientist named Galileo.

oHe saw the moon and its features much more clearly.

o he observed Venus and moons orbiting Jupiter.

The Telescope o Sir Isaac Newton used a much better telescope about 50 years later to observe other objects in space.

o It used two mirrors and one lens.

https://www.youtube.com/watch?v=EGtriSso6r0

The Telescope o In 1936, the first radio telescope was built, detecting radio waves from outer space.

Satelliteso Modern space exploration began in 1957 with the launching of Sputnik I, an artificial satellite.

o satellite: any natural body or artificial object that orbits another object.

o Sputnik carried instruments to measure the density and temperature of Earth’s upper atmosphere.

Astronauts in Spaceo 1961: first Americans in space

o1969: the US landed the first person on the moon.

o Project Apollo landed 12 humans on the moon to set up experiments to get samples of rock from the moon.

Space Probeso space probe: robot vehicle used to explore deep space.

o Voyager space probes have sent back pictures of the outer planets and is still traveling through space.

o Viking I and Viking II landed on Mars

Chapter 2 The Sun’s Energy

The Suno “Earth’s star”

o center of the solar system

o huge ball of very hot gases – hydrogen and helium

o source of almost all energy on Earth – for plants, animals, and wind.

The Sun’s Energyo comes from the fusing, or combining, of small particles to form larger ones.

o the core of the sun has such high temps that, combined with pressure, hydrogen atoms smash into each other to form helium.

oThis is called fusion and it releases light and heat.

The Sun’s Energyo travels in waves.

o some waves are visible light.

o infrared waves = heato ultraviolet waves = tan/burn skin

o radio waves and X-rays

Exploring the Suno 1.4 km across

o100 times the size of the Earth

oCloser to Earth than other stars

oHas several layers that blend together.

Exploring the Suno the layer in the middle is the core.

oIt is the smallest part, but contains the most mass. oMass: the amount of matter in an object.

Exploring the Suno as energy moves out, it passes through the radiation zone. oThis zone is heated from the core.

oFrom there it moves to the convection zone, where convection moves energy to the sun’s surface.

Exploring the Sun

Exploring the Suno the surface is called the photosphere – “sphere of light”

omade of hot, bright areas called granules.

oSunspots are dark areas on the surface. They are cooler than the rest of the sun.

oSolar flare: brief burst of energy from the surface – UV rays, radio waves, X-Rays.

Exploring the SunoThe corona is the sun’s atmosphere – extends 1 million km from the surface.

oIt is only visible during an eclipse.

oStreams of small particles, called solar wind, travel from the corona to the rest of the solar system. oCan cause magnetic storms if they reach Earth.

Exploring the Sun

Chapter 2 How Stars are Classified

Star Magnitudeo How bright a star looks depends on: magnitude (brightness) and distance from Earth.

o If two stars have the same brightness, the one closer to Earth would seem brighter. oIts apparent magnitude (how bright it seems) is

less than its absolute magnitude (how bright it really is).

Types of Starso The color of a star is a clue to its surface temperature.

oBlue stars are the hottest, red stars are the coolest.

Types of Starso scientists use a chart that compares size, magnitude, temperature, and color.

oOn this chart there is a main sequence: a band that runs from top left to bottom right of the chart that includes most stars. oAbout 95% of stars.