THE UNIVERSE NOTES

The universe is everything ~ All matter & energy that exists in the past present and future.

Galaxy: A group of stars (billion or trillions of them!) held together by gravity.

Our galaxy is the Milky way (this is most of the stars we can see)

We are located on the edge of the Milky Way galaxy, so we can see most of it.

Since our universe is huge we measure it in Light Years

1 light year = 95, 000, 000, 000, 000, 000 meters.

(This is the speed light travels in one year)

The speed of light is 300,000,000 m/s

The next closest galaxy to our Milky Way is Andromeda.

It is 2 million light years away!

Edwin Hubble discovered galaxies using telescopes.

Big Bang Theory:

About 15 billion years ago there was a gigantic explosion, making the universe.

There was nothing (no time, space, or energy) the explosion started it all.

Proof of Big Bang

1. The Universe is expanding.

Hydrogen in the stars show a RED SHIFT, meaning that the stars are moving away from us.

This tells us that everything in our universe used to be close together.

2. Galaxies are moving away from us with speeds that are proportional to their distance.

The ones that are twice as far are moving twice as fast.

This agrees with laws of physics when things explode here on Earth.

3. Evidence of Microwaves

There are microwaves left over in space from the Big Bang.

SOLAR SYSTEM NOTES

NEBULAR THEORY:

(Creation of our solar system.)

  1. A cloud of gas and dust in space was spread out by a supernova (giant explosion of a star)
  2. Waves from the explosion squeezed the dust & made the cloud start to collapse
  3. As gravity pulled the gas and dust together, a solar nebula was formed.
  4. The cloud began to spin & collapse
  5. (Just like a dancer that spins faster as she pulls in her arms, the cloud began to spin as it collapsed.)
  6. The cloud grew hotter and denser in the center, with a disk of gas and dust surrounding it that was hot in the center but cool at the edges.
  7. As the disk got thinner and thinner, particles began to stick together and form clumps.
  8. Some clumps got bigger, as particles and small clumps stuck to them, eventually forming planets or moons .
  9. Near the center of the cloud, where planets like Earth formed, only rocky material could stand the great heat. Icy matter settled in the outer regions of the disk

Asteroids, comets and meteorites are solids that never got incorporated into the planets. These objects have survived, unchanged, for 4.56 billion years,"

Evidence of Nebular Theory:

  1. Orbits of the planets lie nearly in a plane with the sun at the center
  2. The planets all revolve in the same direction
  3. The planets mostly rotate in the same direction with rotation axes nearly perpendicular to the orbital plane.

A NEW THEORY (Frank Shu)

In 1996 Frank Shu used the Hubble Telescope and meteorites found on Earth to create a new theory.

The Hubble revealed that most stars are made from disks of whirling gas and dust.

As the disk contracts, it spins faster and faster, funneling tons of interstellar dust toward the center, where temperatures reach 3000 degrees F or more - hot enough to melt metal and vaporize most solids.

Dust particles were melted by the newly emerging disk of our sun, and then launched into space by powerful jets of gas and solar wind.

While in flight, the melted pieces solidified and made the asteroid belt (between Mars & Jupiter)

Some pieces flew into other locations making up our planets.

Dr. Shu studied meteorites and found that they were formed while moving from some place very hot to some place very cold in a very short period of time. Helping to support his theory.

Our Solar System

Nine Planets?

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto

10th Planet found!!!

UB313 found by the Samuel Oschin Telescope, it is larger than Pluto, but not much is known about it.

Our Moon (Its made of Cheese!)

  • As the Moon orbits around the Earth once per month
  • The angle between the Earth, the Moon and the Sun changes; we see this as the cycle of the Moon's phases. We only see one side of the moon!
  • A cycle is 29.5 days (709 hours)
  • The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides.
  • The Moon was first visited by the Soviet spacecraft Luna 2 in 1959.
  • The first landing was on July 20, 1969 ; Neil Armstrong and Edwin Aldrin landed the Lunar Module of Apollo 11 on the Moon's surface. Neil Armstrong was the first human to set foot on the Moon.
  • The Moon is also the only body from which samples have been returned to Earth..
  • Most rocks on the surface of the Moon seem to be between 4.6 and 3 billion years old.
  • Recently, ice was discovered on the moon, scientists believe that it is left over from a comet.

Creation of our moon

Giant Impact

The Earth was hit by another planet while it was being created. This blew out a chunk of the Earth and gravity caused it to revolve around us.

Other Theories:

Sister Planet: The moon was made at the same time, but just smaller, then it got caught by our gravity.

Spinning Theory: The Earth was spinning so fast that it shot off a piece while it was forming which became our moon.