Digging Deepers: Origins of the Universe & Asteroids and Comets

The Big Bang Theory

• scientists call the beginning of the universe “time zero'“

• universe consisted of entirely energy & very hot

• as the universe expanded → temp dropped forming matter

cosmologists

scientists who study the origin & dynamics of the universe

What do cosmologists believe

as matter-cooled atoms were created & under the force of gravity, atoms able to cluster together

What are stars?

clumped together clouds of gas

The Doppler Effect

shifts of wavelength of light produced by distant galaxies as evidence that the universe is expanding

When an object with sound approaches you….

sound waves are compressed which causes a higher pitch

When an object with a sound is moving away from you…

the sound waves are stretched which causes a lower pitch

What color are longer wavelengths of light?

red

What color are shorter w

Where is evidence of the Big Bang Theory found?

in cosmic background radiation

What are the three possibilities of the fate of the universe?

1. expand forever

2. expand to size and stop

3. stop expanding & collapse

Dark Energy

the name for the unidentified energy that is causing the expansion of the universe to speed up

The Nebular Theory

the birth place of our solar system was a nebula

nebula

a cloud of gas & dust

planetesimals

matter in the rest of the disk of the nebula clumped together into small masses

protoplanetary

when planetesimals gradually collied together to form larger bodies

nuclear fusion

when really hot hydrogen atoms in gas combine to form helium

What are terrestrial planets?

Mercury, Venus, Earth, & Mars

Where are terrestrial planets form?

in the inner part of our solar system where temps were high

What are the gas-giant planets?

Jupiter, Saturn, Uranus & Neptune

Where are the gas-giant planets formed?

in the colder, outer parts of the early solar system

contain a lot of hydrogen

Extrasolar Planets

planets orbiting stars other than the sun

law

a way to describe patterns that are observed

theory

provide an explanation for these observations & can be used to predict new phenomena that have yet to be observed

asteroids

leftovers from the formation of the solar system

Where are most asteroids found?

The asteroid belt between Jupiter & Mars

comets

masses of frozen gases & rocky dust particles

Kuiper Belt

a disk-shaped region extending into the outer universe

consists of comets, asteroids, & other rocky bodies

Oort Cloud

a vast region beyond the Kuiper Belt

holds billions of objects

shaped like a sphere

meteoroids

tiny particles in space/leftover dust

meteors

when meteoroids enter earth’s atomsphere

meteorites

when meteors reach earth’s surface