Science Flashcards
Kelpers laws and space
What is Kelpers first law
planets move in elliptical orbits with the Sun as a foci,
What is Kelpers second law
a planet covers the same triangle of space in the same amount of time no matter where it is in its orbit
What is Kelpers third law
a planet’s orbital period is proportional to the size of its orbit (its semi-major axis)
The equation (we did this in a lab) is P3 = A3.
P is the period of revolution, A is the AU (Astronomical units)
How do you make eccentricity
E=D/L
What are asteroids and what are they composed of
Asteroids are rocky, comets are icy, and meteors are much smaller - also meteors are the shooting stars that you see up in the sky.
Is there a friction created when steroids hit the Earths atmosphere and burn up before hitting the ground.
Yes There is friction created when meteors hit the Earth’s atmosphere and most burn up before hitting the ground
What are the two factors that affect gravitational force between any two objects.
Mass and distance are the two factors that affect the gravitational force between any two objects.
When does a planet move fastest
A planet moves faster when it’s at perihelion
When does a planet move slowest
slower at aphelion
What is the equation for speed
Speed = distance / time
how to calculate the diameter of an object that is far away from you.
Distance between you and small circle /diameter of small circle = Distance between you and big circle/diameter of big circle.
Does the apparent diameter change as you get closer to an object
Apparent diameter changes as you get closer and farther from an object.
What is AU
A.U. (Astronomical Unit) is the distance between the earth and sun and is used to measure other astronomical units.
How does Earth’s atmosphere protect against meteor strikes?
The intense heat generated by the meteor striking the atmosphere causes it to either completely burn up or get broken up into smaller pieces.
Gravity – What 2 factors control the strength of gravity between two objects – like the Sun and Earth?
The two factors that control the strength of gravity between two objects are the mass of each object and the distance between the centers of the two objects.
What do they mean - Perihelion and aphelion, perigee and apogee?
Perihelion: The point in the orbit of a planet, asteroid, or comet at which it is closest to the sun
Varying orbital velocity of planets - Where and why does a planet’s orbital speed vary in its orbit around the Sun?
The planet’s speed increases at its perihelion because it is closest to the Sun, and when objects are closer to the Sun, their orbit speeds up. The opposite goes for when the planet is at its aphelion.
Speed/velocity calculations.
Distance traveled divided by the time it takes.
Apparent diameter.
Be sure you understand its meaning and how it varies depending on the viewer’s distance. (The apparent size or apparent diameter of a celestial body means how big the celestial body appears in the sky.) The closer an object is, the greater its apparent diameter.
Astronomical Units the mean distance between the Earth and the Sun – know what it is and be able to convert kilometers into A.U.
1 AU = 149.6 Million KM
To convert KM to AU, divide the KM by 150,000,000
Ex: 300,000,000 KM → 300,000,000 150,000,000 = 2 AU
Heliocentric vs. geocentric models of the solar system.
Heliocentric: The theory that the Sun is in the center of the solar system
Geocentric: The older theory (which is not true) that the Earth is in the center of the solar system
Characteristics of the inner planets (a.k.a. the terrestrials, the rockies) vs. outer planets (a.k.a. the gas giants, the Jovians)
Inner Planets: Are denser, smaller, and are typically made out of rocks and metals. Some have small atmospheres, with the exception of Mercury, which has next to none, and Earth, which has a thick atmosphere.
Outer Planets: Are larger, less dense, and have gassy and/or icy surfaces. They are only less dense on average because they are made of gas. Their cores are probably just as or more dense than the inner planets because of extreme pressure from weight/mass of all the gas above.
The eight planets in order (My Very Educated Mother Just Served Us Nachos) and Pluto.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
What is the shape of the orbit of the Moon around the Earth?
Elliptical, oval-like.
How would the apparent size (a.k.a. apparent diameter) of the Moon change when it is at perigee or at apogee? (The apparent size or apparent diameter of a celestial body means how big the celestial body appears in the sky.) The closer an object is to the viewer, the bigger it appears.
At perigee, the apparent size of the Moon would look bigger compared to its apogee, where it would appear smallest.
How many days does it take for the Moon to complete one revolution?
It takes the moon 27.3 days to complete one revolution.
How many days does it take for the Moon to complete one rotation?
It takes the moon 27.3 days to complete one rotation.
How many days does it take for the Moon to make one complete cycle of its phases – going from New Moon back to New Moon?
It takes the Moon 29.5 days to make one complete cycle of its phases.
Why can we only see the same side (half) of the Moon while it orbits around us?
Because the Moon’s rotation and revolution are completely synced up. This makes it so we can only see one side and never the other.
How much of the Moon is always lit up by the Sun?
50% or one half
Why are we able to see the Moon at all?
Because the light that reflects onto it from the sun hits the Earth.
Why does the Moon show phases to a person looking at it from Earth?
Why does the Moon show phases to a person looking at it from Earth?
What is so unusual about the Moon’s period of rotation and period of revolution, and what is the effect of this fact when viewing the Moon from the Earth?
The moon is tidally locked with Earth (which means its period of revolution and rotation are the same), so we can only ever see one side of the Moon.
What is an eclipse?
When an astronomical object is temporarily blocked or shielded by another astronomical object, this creates a shadow.
Be able to explain the difference between a solar and lunar eclipse.
A solar eclipse is when the moon passes between the Earth and Sun, and the lunar eclipse is when the Earth passes between the moon and sun.
What is the umbra? What would you see in the sky if you were standing in the Moon’s umbra during an eclipse?
The umbra is a dark shadow casted by the Moon during a solar eclipse, and the shadow created by the Earth during a lunar eclipse. It would seem as if it were night if you were standing in the Moon’s umbra during an eclipse.
What is the penumbra? What would you see in the sky if you were standing in the Moon’s penumbra during an eclipse?
The penumbra is a lighter shadow casted by the Moon during a solar eclipse, and the shadow created by the Earth during a lunar eclipse. The sky would not become completely dark like if you were standing in the penumbra, but if you were to look at the sun (with proper eye protection, of course), you would see a “crescent sun” that is partially blocked by the moon.
At what phase of the Moon can a solar eclipse happen?
Only at New Moon
At what phase of the Moon can a lunar eclipse happen?
Only at Full Moon
How is the orbit of the Moon around the Earth aligned (tilted) compared to the orbit of the Earth around the Sun?
The orbit of the Moon around the Earth is tilted compared to the orbit of the Earth around the Sun (by 5 degrees).
Why don’t we have one solar eclipse (at New moon) and one lunar eclipse (at Full moon) every month?
Because the angle of the orbits don’t match up exactly to create one solar eclipse (at New moon) and one lunar eclipse (at Full moon) every month.
How does a planet’s orbital velocity (speed) change during its orbit?
A planet / moon moves faster when it is closer to what it is orbiting around. This is explained in more detail above.
What are the changes in potential and kinetic energy of a planet during its orbit?
An orbiting planet moves fastest when it is closest to its primary (the Sun). An orbiting planet has its greatest kinetic energy at perihelion when it is closest to the Sun and moving its fastest. An orbiting planet has its lowest kinetic energy at aphelion when it is farthest from the Sun and moving its slowest. However, at aphelion, it has its greatest potential energy
- What are the two factors that determine the amount of gravitational pull between two objects – like the Sun and a planet?
Their masses and the distance between them
What causes tides? Be able to explain what causes tides.
The moon and sun’s gravity causes tides
When you are directly facing the Moon, is it high tide or low tide?
It is high tide.
When you are on the exact opposite side of the Earth from the Moon, is it low tide or high tide?
It is high tide.
When you are neither facing directly towards nor directly away from the Moon, is it low tide or high tide?
Low tide
How many high tides and how many low tides are there for every 24-hour day?
Two high tides and two low tides occur every 24-hour day, usually
How many hours is it between high tides?
It is 12 hours 25 minutes between high tides.
How many hours is it between low tides?
It is 12 hours 25 minutes between low tides.
How many hours is it from high tide to low tide?
It is 6 hours 12.5 minutes from high tide to low tide.
What are spring tides? What is the alignment of the Sun, Moon and Earth that causes spring tides?
Spring tides occur when the moon is at full moon, or new moon, spring tides are the extreme tides. The Sun, Moon, and Earth are in a line.
What are neap tides? What is the alignment of the Sun, Moon and Earth that causes neap tides?
Neap tides are caused by Quarter moons, they are ‘average’ tides that are on parallel, opposite sides of the earth, they occur when the Moon and Sun are at right angles.
