Coker astronomy part 1 Flashcards
What is the universe?
It is everything: all matter, energy, and space
What is the Big Bang theory?
It explains the origin of the Universe. It states that the Universe begins extremely small, hot, a dense point called a singularity and then it expanded to what we know today
What supports the Big bang theory?
The light emitted by most galaxies, the redshift, which means the galaxies are moving away and the Universe is expanding. If u go backward in time the Universe was smaller. There is also faint cosmic background radiation in forms of microwave energy. We believe this is left-over radiation from the Big bang
What makes up a galaxy?
A cluster of billions of stars held together by gravity. They are classified according to their shape: spiral, elliptical, and irregular. Our solar system lies int he Milky Way Galaxy
What is a star?
A massive ball of gas that creates its own energy through the power of nuclear fusion.
What is nuclear fusion?
It is a reaction in which the lighter element combine to form heavier elements while releasing a lot of energy during the process
What affects the star’s life-cycle and characteristics?
It depends on the mass. High mass stars are hotter, live shorter lives, and have a more violent death. Low mass stars are cooler, live longer lives, and have quiet deaths
How is the sun’s life?
It is an average mass star, middle-aged and in the middle sequence, meaning it’s in the active part of its life. It is currently fusing Hydrogen into helium.
What is the Doppler effect?
Waves will compress as they move towards you, increasing the apparent frequency. Waves will spread apart as they move away from you, decreasing the apparent frequency
What is the redshift?
It is when the light waves are coming from an object traveling away you have longer wavelengths. Red light wave have longer wavelengths
What is the blueshift?
It is when the light waves are coming from an object traveling towards you, you have shorter wavelengths. Blue light waves have shorter wavelengths
What is a spectra?
Star absorption spectra are a band of visible light scientist use to determine the composition of stars. Each element creates black lines on the absorption spectra. The black line moves when the object is moving towards or away from you
What is Cosmic Microwave Background Radiation (CMR)
Faint microwave radiation coming from every direction that originated from the big bang.
What is an elliptical galaxy
A ball-shaped collection of stars. They’re the smallest and largest galaxies and contains old, yellow, and red stars
What is a spiral galaxy
A flattened disk of stars, gas, and dust orbiting a central nucleus. There are old, red, and yellow stars at the center. The young stars are blue and white stars make up the arms
What makes up the Milky Way galaxy (spiral galaxy)
It contains approximately 200 billion stars. It is 100,000 light years from end to end. Our sun is located 25,000 light years from the center. Our sun is about .25 of the way through the galaxy. There is a supermassive black hole in the center
Why do the spiral arms form in spiral galaxies?
Differentiated rotation stars move at different speeds depending on where they are in the disk
What is an irregular galaxy?
They have no regular shape and they may be young. They may have been torn apart by collision or gravity from a neighboring galaxy
What is the star’s movement as a low mass (Red dwarf)
To the White dwarf
What is the star’s movement as an average mass (sun-sized)
To the giants to the white dwarf
What is the star’s movement as a high mass
To the supergiant then the black holes or neutron stars
What is the geocentric model?
The Earth was in the center of the solar system and everything revolved around the Earth
What is the Heliocentric model?
The sun is the center while the planets revolve around the sun. This is accepted today
What is the satellite?
Any object that orbits or revolves around another object
What is the sun’s satellite?
Planets, asteroids, comets, and meteoroids
What is the Earth’s satellite?
The moon and the Earth revolves the sun directly.
What is a planet?
A large spherical object that orbits the sun and has cleared its orbit of any other object. Planetary orbits are elliptical (Pluto isn’t a planet anymore because it hasn’t cleared its orbit even though its spherical and orbits the sub
What is a Moon?
Any body that orbits a planet or asteroid as those objects orbit the sun
What are the terrestrial planets?
Mercury, Venus, Earth, and Mars
What is a terrestrial planet?
They are rocky, solid, and planets in the inner solar system. They are small, high density, closer to the sun, and have a short period of revolution
What are the Jovian planets?
Uranus, Neptune, Saturn, and Jupiter
What is a Jovian planet?
They’re giant, gas/ice like planets, gaseous, and are part of the outer solar space. They have a lower density, farther from the sun, and have a low period of revolution
What is gravity?
The attraction between any two objects. The more mass= more gravity which the closer the two objects the more gravity there is
What is an orbit?
The path of an object around the sun
What is Perihelion?
Point in the orbit nearest to the sun. It has more gravitational attraction, planets move faster in its orbit (closer to the sun Jan 3rd)
What is Aphelion?
Point in orbit farthest from the sun. There is a less gravitational attraction and the planet moves slower in its orbit (July 4th is when its farthest)
What is an ellipse?
An oval, an elongated circle with two centers called foci. All planets have elliptical orbits
What is a foci?
The central points of an ellipse. The sun is always located at one of the foci
What is the major axis?
The longest straight line distance across an eclipse. It passes through the foci
What is eccentricity?
The degree of flatness or “ovalness” of an eclipse
How are ellipse and eccentricity related?
The less elliptical it is the less eccentric it is and the closer to 0 it is. The orbit is closer to a perfect circle. The more elliptical it is the more eccentric it is and the closer to 1 it is. It’s more of a flatter oval
What is the equation for eccentricity?
The distance between foci (d)/ length of the major axis (L) The number should not be greater than 1
d/L
What is waxing?
Moon phases when the illuminated portion grows right side is illuminated
What is waning?
Moon phases when illuminated portion shrinks left side is illuminated
What is the moon’s period of revolution and rotation?
27.3 days
Why does the same side of the moon always face the Earth?
The Moon’s period of rotation is the same as its period of revolution
What is the order of the moon phases?
New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent
What is the apogee?
The moon is further and appears smaller
What is perigee?
The moon is closer and appears larger
What was the formation of the moon?
Formed from a collision between Earth and a Mars-sized planet about 4.5 billion years ago
What is a super moon?
The full moon is closer to the Earth. The orbit of the Moon is an oval. When a perigee moon also happens at the same time the super moon is seen in the night sky
What is an eclipse?
The blocking of light when a celestial body moves into the shadow of another celestial body
What is the Solar eclipse?
The new moon is blocking the sunlight from the Earth
What is the lunar eclipse?
During the full moon where the earth is blocking the sunlight from the moon
What is a total eclipse?
An eclipse in which the whole disc of the sun or moon is covered. Occurs within the umbra
What is a partial eclipse?
An eclipse in which part of the disc of the sun or moon is covered. Occurs within the Penumbra
Why does the eclipse not occur every month?
The moon’s orbit around the Earth is tilted 5 degrees compared to the Earth’s orbit around the sun
What is a tide?
The cyclic rise and fall of ocean water on Earth caused by the gravitational attraction of the moon and the sun. The moon has a greater effect on the tides because it is closer to the Earth
What is a tide cycle?
Tides occur in a cyclic and repeatable pattern there are approximately 6 hrs between one high tide and one low tide
What is a spring tide?
Occur when the Earth, Sun, Moon form a straight line and it results in the highest high tides and the lowest low tides because the gravity from the sun and the moon are pulling along the same line and occurs during the new moon and full moon
What is a neap tide?
Occur when the Earth, Sun, and Moon form a right angle. This results in the lowest high tides and the highest low tides because the gravity from the sun and moon are pulling in opposite directions. This occurred during the first quarter and third quarter
