The Celestial Sphere
Seasons
Laws of Motion
Atoms & Light
Lunar phases & eclipses
100
Earth is titled on its axis by _____ degrees.
23.5
100
What causes the seasons?
The tilt of Earth's axis
100
What is Kepler's 1st Law of Planetary Motion?
All planets have elliptical orbits, with the Sun at one focus.
100
Which atom is the most abundant atom in the Universe?
the Hydrogen atom
100
True or False: The Full Moon is always opposite the Sun in the sky, meaning that it rises around sunset and sets around sunrise, no matter the location and time of year.
True
200
Using the cardinal directions (north, south, east, west), what direction does the Earth spin? What direction do objects in the sky rise and set?
Earth spins from west to east. Objects in the sky move from east to west.
200
What are the longest and shortest days of the year called?
Solstices
200
Newton used which of Kepler's Laws to develop his own laws of motion?
Kepler's 3rd Law
(P2=a3)
200
As light moves from its source, it spreads out in all directions. It gets weaker as it gets further away, in proportion to the square of the distance it has traveled. What is this law called?
Inverse Square Law
200
What is the difference between a solar eclipse and a lunar eclipse?
A solar eclipse is when the Moon passes between the Earth and the Sun, blocking the Sun’s light and casting a shadow on Earth. A lunar eclipse is when the Earth passes between the Sun and the Moon, casting a shadow on the Moon.
300
Precession is caused by the gravitational pull of the ___ and ___.
Sun, moon
300
What causes the fall and spring Equinoxes?
The tilt of Earth's axis being perpendicular to the sun.
300
Describe Newton's 2nd Law of Motion using words, as well as the equation.
The greater the mass, the greater the force needed to move the object. The greater the force the greater the acceleration.
Force = mass x acceleration (F=ma)
300
What is the astronomy definition of "spectrum"? What are the 2 types of spectra in astronomy?
A spectrum is a plot (or graph or chart) showing the amount of light an object gives off at different wavelengths. This includes absorption spectra and emission spectra.
300
The moon has synchronous rotation. What does this mean?
The Moon's synchronous rotation means that the Moon rotates on its axis at the same rate that it orbits the Earth. As a result, the same side of the Moon always faces the Earth.
400
The apparent “distance” between two points in the sky is really a(n) ______ , measured between the two imaginary lines running from your your eye out to those points.
angle
400
Describe the angle the sun's rays hit Earth during the summer VS during the winter
During summer, the sun's rays hit the Earth at a more direct angle, meaning they strike the surface closer to perpendicular, while during winter, the sun's rays hit the Earth at a more oblique angle, coming in at a steeper slant
400
If you know the orbital period of a planet, which of Kepler's Laws can you use to find that planet's distance to the sun?
Kepler's 3rd Law
(“Law of Harmonies”: The orbital period of a planet (P) is related to the average distance from the Sun (a) by a simple equation: P2=a3)
400
Sketch the general, characteristic shape of the graph of a Blackbody spectrum
400
There are 8 main phases of the moon. Name all 8 phases in order.
New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent.
500
Name 4 ways that the sky is always changing
1. The daily rotation of Earth
2. Earth’s annual motion around the Sun
3. Slow wobble of Earth’s rotation axis (precession)
4. Relative motions of stars, planets, and other objects
500
Define precession, and describe its effects on the seasons.
Precession: Earth’s rotational axis slowly wobbles about, like a spinning top.
Precession causes seasonal contrasts to be more extreme in one hemisphere and less extreme in the other. For example, currently the Northern Hemisphere experiences more moderate seasonal variations, while the Southern Hemisphere experiences hotter summers. In about 13,000 years, this will flip.
500
Using the equation for Newton's Law of Gravity, is the force of gravity proportional to or inversely proportional to mass? Is the force of gravity proportional or inversely proportional to distance?
Newton's Law of Gravity: F = G (m1m2)/r2
The force of gravity is proportional to mass, and inversely proportional to distance (r).
500
Describe how an atom can gain energy and lose energy (there are multiple ways, but i'm specifically looking for the way that was described in lecture!)
An atom can gain energy when 1 or more of its electrons absorbs a photon and moves to a higher energy level. It can lose energy when 1 or more of its electrons emits/releases a photon and falls to a lower energy level.
500
Which phase is the moon in during a solar eclipse? What phase is the moon in during a lunar eclipse?
New moon.
Full moon.