Do Now 2/11/14

1. List the 7 steps of universe formation2. What is accretion?

Earth’s Seasons• Earth’s axis is tilted 23.5o

• March 20/21 – Spring Equinox (#4)

• June 21/22 – Summer Solstice (#1)

• September 22/23 – Autumn Equinox (#2)

• December 21/22 – Winter Solstice (#3)

The Moon• Because the moon has no atmosphere there are

extreme differences in the moons temperature• The surface of the moon consists of:– Highlands, Maria, Impact Craters, Ejecta, Rays

The Moon

• Radiometric dating suggests the moon is between 3.8-4.6 Billion Years Old

• It is believed that the moon was heavily bombarded during it’s first 800 million years

• Maria are between 3.1 and 3.8 Billion Years old– They are believed to have been craters that have

been filled up with lava

Radiometric dating suggests the moon is between 3.8-4.6 Billion Years Old

It is believed that the moon was heavily bombarded during it’s first 800 million yearsMaria are between 3.1 and 3.8 Billion Years old

• They are believed to have been craters that have been filled up with lava

The Moon• The moon is made up of layers like the

Earth• The moon does experience quakes however they

are incredibly weak• There are no active volcanoes and no magnetic

field so scientist theorize that the moon is tectonically inactive

Earth-Moon Motions• The moon moves counterclockwise

to Earth • Perigee – moon is closest to

Earth• Apogee – moon is farthest from

Earth• Phases of the moon are the different amounts of light

that appears on the moon (see illustration)

Phases Of The Moon• Due to the movement

of the Moon around the Earth our viewpoint changes.

• The Moon appears to go through phases

http://home.hiwaay.net/~krcool/Astro/moon/moontides/

• Spring tides occur during the full moon and the new moon.

• Neap tides occur during quarter moons.

• When the sun and moon are aligned, there are exceptionally strong gravitational forces, causing very high and very low tides which are called spring tides, though they have nothing to do with the season. When the sun and moon are not aligned, the gravitational forces cancel each other out, and the tides are not as dramatically high and low. These are called neap tides.

Eclipses

• A solar eclipse occurs when the moon passes directly between the Earth and the Sun and blocks our view of the sun

• A lunar eclipse occurs when the Moon passes through Earth’s shadow

Lunar Eclipses• Occurs during full moon phases• Penumbra – light is partially blocked by Earth• Umbra – light is completely blocked by Earth

Solar Eclipses

• Occurs when sun is blocked by the moon• If the moon is partially blocking the sun, a

partial solar eclipse will occur

Do Now 2-17-141. List 4 things that are proof of universe formation.2. What does spring/fall equinox mean? 3. What does winter/summer solstice mean?4. What season is show on earth #4?

The Sun

The Sun

The Sun

• The sun is the largest object in the solar system• The sun is 330,000 times as massive as Earth, 1048

times as massive as Jupiter• Contains 99% of all mass in the solar system

The Sun

• The sun’s average density is similar to the gas giants• However the center of the sun is about 13X the density

of lead

• The interior is about 10,000,000 K• Many of the gases are completely ionized, composed of

only atomic nuclei and electrons(Plasma)

The Sun’s Atmosphere

• Layers of the Sun–Photosphere–Chromosphere–Corona

Photosphere

• The most inner layer of the sun is the Photosphere

• This is the visible surface of the sun• Most of the light emitted by the sun comes from this layer• The top 2 layers are transparent

Chromosphere

• The 2nd layer of the sun is the chromosphere• Usually only seen during a solar eclipse• Usually appears red

Corona

• The top layer is known as the corona• The temperature can range from 1 Million 2 Million

degrees Kelvin• The gas is so dim it can only been seen when the

photosphere is blocked by several instruments

Solar Winds• Solar winds are gases that flow outward from the

corona at high speeds• Solar winds flow at about 400 km/s• When they reach the Earth they are trapped in the Earth’s magnetic

field

• This causes what we know as Auroras

Solar Activity

• Sunspots-Dark spots on the surface of the Photosphere. Appear dark because they are cooler than the surrounding Sun

• Solar Flares-Violent Eruptions of particles and radiation from the surface of the sun

• Prominence-Arc of gas that is ejected from the chromosphere

Solar Interior

• Within the core of the sun where pressure and temperature are high fusion occurs– Fusion-Combining of lightweight nuclei with

heavier nuclei• Fission is the splitting of heavy atomic nuclei

into smaller atomic nuclei

Solar fusion video

http://www.youtube.com/watch?v=TOErr4xntHE&feature=related

• http://www.youtube.com/watch?v=Ee--KkyR7CU

Spectra• Spectrum is visible light arranged according to

wavelengths– Continuous-Produced by a glowing solid or liquid– Absorption-There are a series of dark bands which

are caused by different chemical elements that absorb light at specific wavelengths

– Emission-Comes from a non-compressed gas, you can see bright lines at different wavelengths

Black Holes

• Some stars are too massive to form neutron stars• This could eventually form a black hole

• A black hole is a small but extremely dense object.

• Gravity is so immense that nothing (even light) can escape

Other Galaxies

• Edwin Hubble first discovered the Andromeda Galaxy.

• By studying these objects he concluded that they were much too far away to be located in the Milky Way

•Edwin Hubble first discovered the Andromeda Galaxy.

•By studying these objects he concluded that they were much too far away to be located in the Milky Way

Other Galaxies

Classification

• Hubble later went on to categorize galaxies based on their shapes

• Spiral Galaxies– Barred Spirals-Have elongated central region or a bar

from which the spiral arm extends– Normal Spirals-Do not have bars

Classification

• Normal and barred spirals are subdivided based on how tightly the spiral arms are wound

• The letter a represents tightly wound arms and c represents loosely wound

• Elliptical galaxies are galaxies that are flattened into disks and do not have spiral arms– Round ellipticals are classified as E0– Elongated ellipticals are classified as E7

Exit Ticket 2/17/14

Think of a way that you could teach the seasons to a class of middle school students.

Draw your ideas or write them out on your white sheet of paper.

**Make sure to include how they will understand the tilt causes the seasons and how they will be able to recognize each season based on a photo.