Space Study GuideName ______

LT 1: I can describe and give evidence for the Big Bang Theory (in class, we also compared to other theories- these are for general information and will not be included on this assessment)

The Big Bang Theory is the current scientific model that explains the formation of the universe with evidence we have observed. The Big Bang Model is summarized in the following:

  • The universe began 13-15 billion years ago when it expanded rapidly from a single point.
  • At that moment, all matter and energy was created. Before then, there was nothing.
  • Right after the “Big Bang” event (which scientists think was not like an explosion as the name suggests), the temperature was VERY hot.
  • BBT says that the universe would be abundant in the lightest elements of Hydrogen (H) and Helium (He).

As technology increased, scientists made more and more observations that supported the Big Bang Model.

  1. In 1929, Edwin Hubble observed that the spectral lines from other galaxies tended to always shift toward the red end of the spectrum. According to the Doppler Effect, causes this change of observed frequency of electromagnetic radiation when the object or the observer is moving. When objects are moving away from us, we call it red shifting because the spectra appear redder. When objects are moving toward us, the spectral lines are shifted toward the blue end of the spectrum, and we call it blue shifting. Due to this red shifting of nearly every other galaxy, Hubble announced that the universe is expanding and that nearly every other galaxy was moving away from us.
  2. Scientists using radio telescopes have observed that no matter where in the sky they look, they pick up cosmic background radiation (CBR). This radiation is leftover microwave radiation leftover from the Big Bang event and fills the universe. The universe has an average temperature of 2-3˚ Kelvin, which is what the Big Bang Model predicts would be the temperature after cooling from the event.
  3. Scientists have observed an abundance of Hydrogen andHelium throughout the universe. The amount of H and He isotopes is a very close match to predictions of the Big Bang Model since H and He have the least amount of mass, they would be the first elements to form. These elements are necessary to make the heavier elements.
  4. The age of the universe as predicted by the Big Bang Model is consistent with data we have observed. No item identified in the universe is older than 13-15 billion years, the age predicted by the model.

There are many different theories on the origin of the universe. The following is just a short list of the more popular ones leading up to what we know today.

Theory / Summary / “Problem”
Creationism/ Intelligent Design /
  • God or a higher power created the universe and everything in it.
  • Relatively recent correlations ongoing that link Creationism with the Big Bang Theory
/ Lacks quantitative data
Static Theory /
  • Theory popularized/ believed by Einstein (1917).
  • Says that the universe has always been here
  • Says space is neither expanding nor contracting.
/ We now have evidence that the universe IS in fact expanding (red shifting of galaxies).
Steady State Theory /
  • Also known as the Infinite Universe Theory or Continuous Creation Theory.
  • Believed in by Edwin Hubble and is an offshoot of the Static Theory.
  • Thought that new matter is continuously created as the universe expands and that most matter created is Hydrogen.
/ Does not explain the presence of cosmic background radiation.
Many Bang Theory /
  • Similar to the Big Bang Theory, but instead of one “big bang,” explosions on all scales occur continuously.
/ Lacks evidence
Multiverse Theory /
  • More recent theory
  • Instead of having one universe, there are multiple universes- a different universe for every possible outcome for anything that has happened.
/ Currently impossible to collect data for

LT 2: I can describe the life cycle of a star.

Stars begin as a cloud of dust and gas called a nebula. As the gas spins and starts to condense and come together, the beginnings of a star are formed in the stage called a protostar. As the star further condenses, temperatures rise and the hydrogen atoms begin violently colliding. These collisions result in nuclear fusion where the hydrogen atoms combine to form helium and a huge amount of energy is given off. At this point, the star is “born,” and is classified as a main sequence star. Our sun in about half way through the main sequence. As fuel for the star begins to run out, the star pushes gas outward and becomes a red giant. What comes after the red giant stage depends on the mass of the star.

  • Smaller stars that are equivalent to 0-8 of our suns mass will enter the white dwarf stage where the star appears smaller and shines brightly. When its fuel runs out it becomes dark cold and is called a black dwarf.
  • Medium sized stars that are 8-20 of our solar masses will go from a red giant stage into a supernova. From there, it can go into a neutron star, or a spinning neutron star, called a pulsar.
  • Large and massive stars, that of more than 20 or more of our suns mass, go from a red giant into the supernova stage. Then, because of their large mass, can condense in on themselves and form a black hole.

A Hertzsprung-Russell (H-R) diagram is a graph that plots a stars luminosity and temperature. You can tell where a star is in its life cycle based on its position on and H-R Diagram.

LT 3: I can explain how the different elements are formed.

All matter is made up of atoms. The number of protons within the nucleus determines the type of element. An element can have different forms, called isotopes, based on the number of neutrons in the nucleus. For example, an ordinary hydrogen nucleus contains just one proton. But deuterium, an isotope of hydrogen, has one proton and one neutron in its nucleus.

The entire universe shares a common set of elements. In the very early universe, the only elements were hydrogen and helium. But since the formation of stars, lighter elements within the stars began fusing to create heavier elements, producing all the other naturally occurring elements. Under the extremely high temperatures and pressures within the core of stars, atoms collide at high enough speeds to overcome the usual electromagnetic repulsion of nuclei, allowing nuclear fusion to occur.

LIGHT ELEMENTS: In the main sequence stage of a star, Hydrogen fuses to form Helium. When all the hydrogen is used up, the star pushes out gases and the core heats up. Helium begins to fuse into heavier elements such as Carbon. This continues to form all elements lighter than Iron (#26 on periodic table).

HEAVY ELEMENTS: “Regular” stars do not get hot enough to fuse elements with nuclei heavier than iron. Elements heavier than iron are only produced in the extraordinary conditions created by the collapse and explosion of a star -- a supernova.

LT 4: I can describe the life span of our sun and how its radiation impacts Earth {solar flares (“space weather”), 11-year sunspot cycle, non-cyclical variations}

The Sun is always active. It has weather. It has storms. And its storms can affect Earth's weather.

Sunspotsare magnetic storms on the surface of the Sun.

Solar flaresare intense blooms of radiation that come from the release of the magnetic energy associated with sunspots. The NOAA ranks solar flares using five categories from weakest to stongest: A, B, C, M, and X. Each category is 10 times stronger than the one before it. Within each category, a flare is ranked from 1 to 9, according to strength, although X-class flares can go higher than 9. According to NASA, the most powerful solar flare recorded was an X28 (in 2003).

Coronal mass ejections(CMEs) are bursts of solar material (clouds of plasma and magnetic fields) that shoot off the sun's surface. Other solar events includesolar wind streamsthat come from the coronal holes on the Sun andsolar energetic particlesthat are primarily released by CMEs.

What is a Solar Cycle?

The number of sunspots increase and decrease over time in a regular, approximately 11-year cycle, called the solar or sunspot cycle. The exact length of the cycle can vary. More sunspots mean increased solar activity—flares and CMEs. The highest number of sun spots in any given cycle is designated "solar maximum," while the lowest number is designated "solar minimum."

Solar activity affects the Earth in many ways, some which we are still coming to understand.

  • Damage to21st-century satellites and other high-tech systemsin space can be caused by an active Sunwhich generates geomagnetic storms.
    Even in inactive solar cycles,the Sun emitslarge solar flares—which could cause billions of dollars in damage to the world's high-tech infrastructure—from GPS navigation to power grids to air travel to financial services.
  • Radiation hazardsfor astronauts and satellitescan be caused by aquiet Sun. Weak solar windsallow more galactic cosmic rays into the inner solar system.
  • Weather on Earthcan also be affected. According toBob Berman, astronomer forThe Old Farmer's Almanac: Recently, NOAA scientists concluded thatfour factors determined global temperatures: carbon dioxide levels, volcanic eruptions, Pacific El Niño pattern, and the Sun's activity.
  • Affects to Humans- sunburn and cancer linked to exposure to UV (ultraviolet rays)

LT 5: I can explain how gravity affects objects on Earth and in Space.

Gravity plays many roles in space. The following is a list of main roles gravity plays.

  • Gravity is responsible for the accretion (the coming together of particles due to gravity) of planets and stars. If it was not for gravity, planets and stars would not have been able to form.
  • Gravity is responsible for holding things in orbit around each other. It is responsible for
  • Holding the moon in orbit around the Earth (important for daily cycles of many living things).
  • Holding artificial satellites in orbit around the Earth (important part of our daily lives including technology, TV, cell phones, weather, and research…)
  • The Earth in orbit around the sun (responsible for our calendar year)
  • Our solar system revolving around other solar systems and
  • Our galaxy revolving around other galaxies.
  • Gravity is responsible for holding gases around a planet and forming the atmosphere. If it were not for this, there could be no life on Earth.
  • The Earth’s gravity is responsible for things being held to the earth- living and non-living things.
  • The moons gravitational attraction to the Earth is responsible for our ocean tides.

LT 6: I can explain and give evidence for the theory on the formation of the Earth and our solar system.

The nebular hypothesis is the current scientific model for the formation of our solar system.

  • Scientists believe that our solar system began 5 billion years ago as a huge spinning cloud of dust and gas called a nebula.
  • The dust and gas collapsed in on itself because of accretion (the coming together because of gravity) and formed the sun (same process as other stars).
  • As the cloud collapsed, it formed into a rotating disk and spun faster and faster which caused it to flatten.
  • Planetesimals, or particles that become planets, began to form in the disk.
  • As the planetesimals grew larger, their gravitational attraction also grew, and collected more gas and dust from the nebula.
  • Some planetesimals collided with larger ones and combined to form larger and more stable planets.
  • The warmer, inner planets were rocky (terrestrial), while the cold, outer planets accumulated lightweight gases.
  • Each planet was massive enough to sweep up the material in its region, so their orbits are separate from each other.
  • Asteroids and other rock are leftover debris from the formation of the solar system.

Evidence for this Nebular Theory include…

  • The orbits of the planets lie in nearly the same plane, with the sun at the center.
  • Planets all revolve in the same direction.
  • Planets axes are nearly perpendicular to its orbital plane

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Space Study Guide