Unit 1 - Astronomy Review Flashcards
What is the Big Bang Theory?
The model explains the universe’s history from a tiny fraction of a second after it came into being up to the present time.
Why are Supernovas important?
They are one of the original sources of the elements heavier than Iron in the universe.
What is the Nebular Hypothesis?
How solar systems form, due to the rotation of a cloud of gas and dust rotating in space.
What is the shape of the Earth?
The Earth is an Oblate Spheroid.
What is the name of our Galaxy? Where is our solar system in it?
Our Galaxy is called The Milky Way. Our Solar System is on the outer edge of the Milky Way.
What is Rotation?
Turing or spinning of a body on its axis.
What is Revolution?
The motion of a body (like a planet or moon) along a path around some point in space.
What causes Seasons?
The revolution of the Earth and the axial tilt of the Earth is responsible for the seasons.
What is the Mass of a Photon?
The photon is a massless particle.
Why is Stellar Parallax important?
It gives more accuracy to the cosmic distance ladder and improves the knowledge of distances in the Universe.
What is Heliocentrism? Geocentrism?
Heliocentrism is Sun Centered and Geocentrism is Earth Centered.
What is Kepler’s First Law?
Law of Ellipses - The path of each planet around the Sun is an ellipse, with the Sun at one focus
What is Kepler’s Second Law?
Law of Equal Areas - Each Planet revolves so that an imaginary line connecting it to the Sun sweeps over equal areas in equal intervals of time. (Equal area, Equal time)
What is Kepler’s Third Law?
Law of Harmonies - The orbital periods of the plane and their distances to the Sun are proportional
What is Precession?
Precession is the change in the direction of the axis, without a change in tilt (does not affect seasons but does change the ‘northern star’).
What is Nutation?
Nutation is wobbling around the precessional axis by ½ degree in either direction over 18 years due to the Moon. Can vary slightly and influence seasonal effects (the wobble in precession)
What is Barycenter?
The center of mass of two or more bodies, usually bodies orbiting around each other, such as the Earth and the Moon.
How long does it take for the Moon to Revolve around Earth? What is special about this?
It takes the Moon 29 days to orbit the Earth. It is special because February has exactly 29 days each year.
Describe the Phases of the Moon.
- New Moon: Moon is almost directly between the Sun and Earth (start of cycle)
-Waxing Crescent Moon: A bit of the sunlight side of the moon shows on the right side
-First Quarter Moon: The Moon is a quarter of its way around the Earth. It is in its first quarter phase
-Waxing Gibbous Moon: The Moon is increasing in light between a first quarter Moon and a full Moon
-Full Moon: Two weeks have passed since the new Moon. We see the entire face of the Moon shining
-Waning Gibbous Moon: The Moon is decreasing in light between a full Moon and a last quarter Moon
-Last Quarter Moon: The Moon is three-quarters of its way around Earth. It is in its last quarter phase
-Waning Crescent Moon: A bit of the waning sunlight side of the moon shows on the left side
How does the Moon affect tides?
Because the force of gravity decreases with distance, the side of the Earth closer to the Moon is slightly deformed. Because the position of the Moon changes only slightly during a single day, the Earth will “rotate through” the tidal bulge
What is Nuclear Fission?
The process of splitting atoms
The process of splitting atoms
Fusing atoms
What is the Difference between Convection, Conduction, and Radiation?
Conduction is transferred through collisions, Convection, through the movement of a fluid, and Radiation, through waves or particles.
What is the Electromagnetic Spectrum?
The Electromagnetic Spectrum explains the types of energy that can be produced based on frequency.
