Astronomy

The Moon’s Topography -Impact craters from meteorites are frequent. -Lava flows during cooling blanket the moon.

Moon Formation - The leading scientific theory states 100 million years after the Earth formed, a planet sized object collided with Earth sending debris into orbit. https://www.youtube.com/watch?v=mQAdYWcA7ig

Moon Phases - Moon revolves around earth reflecting the sun towards earth. – “Dark Side” of the moon because the rotation and revolution are both 27.3 days. Waxing = getting brighter Waning = getting darker

Eclipses Umbra = total shadow Penumbra = partial shadow - Lunar eclipses occur when the Earth is located between the Sun and the Moon. - A solar eclipse occurs when the Moon comes between the Sun and Earth, and the Moon’s shadow hits Earth’s surface.

Lab: Charting Moon Phases

T: Big Bang Theory

Scientific Theory Explanation of natural phenomena. Supported by evidence through observation. Tested many times. Widely accepted in the scientific community. May change over time with new technology or evidence.

Scientific Law Laws describe how the natural world behaves. “Law describes what, and theories explain why.” Hubble Telescope Image

Universe Our sun is one of 1,ooo,ooo,ooo stars in the Milky Way Galaxy. The Milky Way Galaxy is one of 1,000,000,000 galaxies in Universe. Hubble Telescope Image

Big Bang Universe estimated at 13.8 billion years. - The most widely-accepted scientific theory on the beginning of our universe. Universe estimated at 13.8 billion years. Universe started as a dense, hot, super massive ball that exploded in all directions.

Supporting Evidence Other galaxies have a red shift in light showing that they are moving away from us. Doppler effect explains the change in the wave frequency. Cosmic background radiation has been discovered from the Big Bang, which is made up of faint radio signals.

Five billion years ago, there was no sun. There was no earth. A diffuse cloud of gas and dust swirled in the blackness. This cloud would become the Sun and the planets we know. ………………………Our solar system was born.

The Nebular Hypothesis The solar system developed from a Nebula - a cloud of gas and dust particles. First, the heaviest elements contract towards the center of the cloud forming the sun.

Second, the nebula began to spin around the sun, and it flattened into a disk.

Third, particles in the cloud began to collide & stick together forming planetesimals (small early planets). What is expected from the student

Planet Formation Planets formed out of dust and debris that collided and stuck together to form a larger and larger mass- a process know as accretion.

…and our solar system was born How do we know it happened this way? The Hubble Space Telescope has allowed us to observe other solar systems being formed.

How do we know when it happened? Radiometric dating determine the age of rocks, fossils or other specimen using the radioactive decay of an element. The radiometric dating of meteorites finds that they date back to 4.6 billion years ago.

Solar System The Solar System consists of the Sun and those celestial objects bound to it by gravity, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago.

We categorize planets into 3 groups: Inner Planets known as Terrestrial (Earth like) Outer Planets known as Jovian (Jupiter like) Exo Planets known as Dwarf (very small)

Inner Planets The inner planets are those found closest to the Sun: Mercury, Venus, Earth, and Mars. The inner planets are sometimes called the Terrestrial (Earth-like) planets. This is because all the inner planets have rocky crusts, dense mantle layers, and very dense cores.

Outer Planets The outer planets are those found beyond the asteroid belt: Jupiter, Saturn, Uranus, and Neptune. The outer planets are known as the Jovian (Jupiter-like) planets. They are much larger, are gaseous (outer layer is mostly hydrogen gas), & have a hot liquid core. These planets are less dense, & all four have ring systems.

Dwarf Planets The newest group is called dwarf planets: Ceres, Pluto, and Eris. More dwarf planets are expected to be announced in the coming months. The major reason these are considered dwarf planets is the fact that mass of these objects have not cleared the “neighborhood” around their orbit.

Lab: Build your own “Scale Model” of the Solar System.