Early Universe
This Theory states that theuniverse began 13.8 billion yearsago as a small, dense volumeand then rapidly expanded andhas cooled ever since. What is the name of this theory?
What is a galaxy?
A collection of gas, space dust and stars
This term describes gravity pulling together gas and dust here to begin forming a protostar, the precursor to a star.
nebula
What is astronomical unit (AU)?
This unit of measurement is the average distance between the Earth and the Sun.
This celestial body is the only planet that contains water in all 3 phases and the temperature is just right to sustain life.
Earth
What are the two pieces of evidence for the Big Bang Theory? Explain both.
Cosmological Red Shift – almost all objects in universe moving away from each other.
Cosmic Background Radiation – Radiation left over from the Big Bang has stretched to become microwaves which we can detect from all areas of the universe.
What information can be learned by looking at starlight?
1) Temperature 2) Composition 3)whether it's moving towards or away 4) how fast it is moving.
These reactions involve two elements combining together to form a heavier atom, while releasing a large amount of energy.
nuclear fusion
What is light year?
This measure is the distance that light travels in one year, in a vacuum.
This is the atmosphere of the sun.
Corona
What is Hubble's Law? Describe.
The speed of galaxy is proportional to the distance from Earth. Greater distance = moving faster.
What is the term for spherically shaped object in space made up of hot gases?
stars
After fusion of hydrogen, the star swells up into a red giant. The outer gas drifts away as a planetary nebula and a white dwarf remains, which will eventually cool into a black dwarf. This is the life cycle of ________ mass star.
intermediate
What is parallax?
This is the apparent shift in position of a nearby object against a distant background when viewed from different perspectives.
Describe the difference betweenan Asteroid and a Comet.
Asteroids are non-spherical space rocks that orbit the sun (most in Asteroid belt between Mars and Jupiter). Comets are rocks covered in ice that give off icy fragments and dust in their “tails”. Originate in the Oort cloud.
What is the Doppler Effect? Explain.
Waves bunch up and increase in frequency in front of a moving source and stretch out and decrease infrequency behind a moving source. This can affect our perception of sound, color, etc. due to changes in frequency of the wavelength.
Describe the 3 types of galaxies.
Spiral – Pinwheel Shape and flattened disc. Rotates the fastest with new stars in arms.
Elliptical – spherical to ellipse in shape with old stars.
Irregular – No shape. Mix of old and new stars.
What is a neutron star and how is it formed?
When a smaller, high mass star dies, it collapses into a dense star composed of neutrons. It is 20 km-wide and spin 30x per second.
When would you experience a greater parallax? closer or further?
closer
Explain how a solar eclipse occurs.
During a solar eclipse, the moon passes between the sun and the Earth, temporarily blocking the suns light from reaching the Earth.
Explain the blue shift and red shift.
Light given off by a star that is moving away from us will have its wavelengths of light stretched out – and become lower frequency light – which is towards the red end of the spectrum. The opposite happens if it is heading towards us (blue shift).
What is a black hole? How is it formed? Material that falls into a black hole is no longer part of our universe. This is called ______________.
If the star starts out greater than 20x the mass of the sun, when it dies, it becomes a Black Hole, which is a mass with no volume. This is called singularity.
Describe the main points of the life cycle of a high mass star.
1) Fusion of hydrogen into helium, core collapse
2) Fusion helium -> carbon, becoming red giant. Temp increase.
3) Fusion into iron -> star collapse and supernova formed
4) Star either become a black hole or a neutron star, depending on how massive the star was.
How does parallax applied to measure distance in space?
Using distant stars, the parallax angle can be measured for the object we want to know the distance to
The parallax angle is divided by 2 so you form a right triangle (triangulation) to determine the distance to the object.
Describe why we experience different seasons in the northern and southern hemispheres of Earth.
Earth is tilted at 23.5 degrees. Tilt is always in the same direction. This causes the sunlight to strike the Earth at different angles in its orbit around the sun. In our winter, sunlight /solar energy spreads over a much larger area of land at a shallower angle and in the summer, it spreads over a smaller area of land at a more direct angle. The differing amounts of solar radiation creates different lengths of days and conditions.