Astronomy Final Flashcards
What do you call when an object moves away and light stretches to the red part of the EM spectrum?
Redshift
What is William Hershel famous for?
He discovered infrared light.
How are wavelength and energy related?
Longer wavelength = Less energy
Shorter wavelength = More energy
How thick is the Milky Way galaxy?
100,000 light years
List the EM spectrum from longest/weakest to shortest/strongest.
Radio Microwave Infrared Visible Ultraviolet X-Ray Gamma
What happened 300,000 years after the Big Bang?
Matter begins to condense.
About how many planets are there in the galaxy?
100 million - 400 million
What is in the center of the galaxy?
A super massive black hole.
How far away is Earth from the sun?
93,000,000 miles
Is the universe static or expanding?
Expanding
How far is Earth and Proxima Centauri?
4 light years
What is the current theory of how the universe began?
The Big Bang
List a type of astronomer
Planetary
How far does light travel in a year?
6 trillion miles
Define Astronomy
The study of the moon, stars, planets, comets, gas, galaxies, dust, and other non-bodies & phenomena.
List 2 problems astronomers have with viewing the sky. How do they fix the problem?
Surrounding light. Move away.
Air Temperature. Move higher.
List the 3 main pieces of evidence of the Big Bang.
- Cosmic Background Radiation
- Redshift
- Specific amounts of Helium, Lithium, & Deuterium.
What does Hubble’s Law tell us?
The universe is expanding.
What is the speed of light?
186,000 mps
What is an astronomical unit?
93 million miles
Earth to Sun
What happens in the core of a star
Elements are fused to make heavier elements and release energy in the process
(Thermonuclear Fusion)
How are the formations galaxies and stars similar?
Both are formed by gravity and large clouds of gas.
What would happen if matter had been distributed evenly?
Gravity could not form clumps of gas to form stars, galaxies, etc.
Which star class has a high temperature and blue in color?
O
What are most stars classified as in the HR diagram?
Main Sequence
What is not a stage of a massive star?
Brown Dwarf
What can we find out of a star’s emission spectra?
What elements are present.
What is the source of all the heavy elements of the universe?
All came from the life cycles of stars.
What high mass stellar core rotates at speeds of 100s a second?
A neutron star
What will sun eventually become?
White Dwarf
What is the primary fuel for a star?
Hydrogen
What is the classification of stars?
O, B, A, F, G, K, M
What does gravity depend on?
Mass and Distance
Define gravity
A fundamental force of the universe that causes objects to be attracted to each other.
What is a black hole?
A ultra dense remains of a star compressed into a tiny space that gravity is so strong that not even light can escape.
Are the majority of stars dimmer or brighter?
Dimmer
What star could end up as a black hole?
A massive star
What does the x axis of a HR diagram tell us? y?
Temperature.
Luminosity.
What is the term for Earth’s wobble?
Procession
What inner planet has 2 moons?
Mars
What is the longest period of daylight for the Northern Hemisphere?
Summer Solstice
What type of motion allow us to measure a single day?
Rotation
What is the current theory of how solar systems are formed?
Condensation Theory
Where do the majority of comets are from?
Oort Cloud
Of all the eight planets, which do we know the most about other than Earth?
Mars
What do you call a planet that has not cleared its orbit?
Dwarf Planet
What do you call a planet outside our solar system?
Exoplanet
Which planet has the hottest surface temperature?
Venus
What material is at the center of the inner planets?
Metal/Rock
About how long does it take for the moon to orbit Earth?
27.3 days
Name a dwarf planet other than Pluto.
Eris
What is the IAU’s definition of a planet?
1) must orbit a sun
2) has enough mass to be nearly round or is round
3) has cleared the neighborhood
What are the eight planets and what are they made of?
Mercury, Venus, Earth, & Mars - Rocky Jupiter & Saturn - Gas Uranus & Neptune - Ice
What is Kepler’s 1st law?
All planet orbits are elliptical.
What is Kepler’s 2nd law?
The closer a planet is to its star, the faster it moves.
The farther a planet is to its star, the slower it moves.
What is Kepler’s 3rd law?
Distance and speed are of revolution are directly related.
Give 2 reasons why scientists think Mars once had life
It once had water and some areas are similar to Earth.
What type of eclipse is it when the moon’s shadow passes in front of the sun?
Total Solar Eclipse
Mercury, Venus, and/or Mars?
Has a retrograde motion of rotation
Venus
Mercury, Venus, and/or Mars?
Orbital period of only 88 Earth days
Mercury
Mercury, Venus, and/or Mars?
Has the largest mountain feature in the solar system
Mars
Mercury, Venus, and/or Mars?
Has no moon
Mercury and Venus
Mercury, Venus, and/or Mars?
Brightest object in the sky
(After the sun and moon)
Venus
Mercury, Venus, and/or Mars?Smallest planet
Mercury
Mercury, Venus, and/or Mars?
Once had liquid water
Mars
