Term
| Earth is made mostly of metals and rocks. Where did this material come from? |
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Definition
| It was produced by nuclear fusion in stars. |
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Term
| Light takes approximately one second to travel from the Earth to the Moon. This means that the moon is approximately... |
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Definition
| 300,000 kilometers from the Earth |
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Term
| Which of the following correctly describes the concept of galactic recycling? |
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Definition
| New stars are continuously being formed in the Milky Way out of gas that has been ejected from a previous generation of stars. |
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Term
| Which of the following is smallest? |
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Definition
| Size of a typical planet < 1 light second, 1 AU, Size of a star, Size of a galaxy |
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Term
| By studying distant galaxies in the 1920s, Hubble made the following important discovery that led us to conclude that the universe is expanding. |
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Definition
| All galaxies outside the Local Group are moving away from us, and the farther away they are the faster they're going. |
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Term
| Light travels at 300,000 km/sec. About how far does light travel in 10 years? |
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Definition
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Term
| What is the Sun mainly made of? |
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Definition
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Term
| Which of the following situations would result in the longest days during summer? |
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Definition
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Term
| If your year was twice as long, but Earth's rotation period and axis tilt were unchanged, then.. |
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Definition
| The four seasons would each be twice as long as they are now. |
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Term
| Which of the following statements about Milky Way galaxy is not true? |
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Definition
True - Contains 100 billion stars
True - About 100,000 light-years in diameter.
True - One rotation of the galaxy takes about 250 million years.
True - There are more low mass stars than high mass ones.
False - Our solar system is located very close to the center of the Milky Way galaxy. |
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Term
| What effect or effects would be most significant if the Moon's orbital plane were exactly the same as the ecliptic plane? |
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Definition
| Solar eclipses would be much more frequent. |
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Term
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Definition
| The annual path of the Sun around the celestial sphere. |
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Term
| You are standing on Earth's equator. Which way is Polaris, the North star? Based on your answer, what's your latitude? |
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Definition
| On the northern horizon, latitude is zero degrees. |
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Term
| From Kepler's third law (p^2 = a^3), a hypothetical planet that is twice as far from the Sun as Earth should have a period of.. |
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Definition
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Term
| During the time that a planet is in its period of apparent retrograde motion.. |
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Definition
| Over many days or weeks, the planet moves westward relative to the stars, rather than the usual eastward relative to the stars. |
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Term
| Which of the following observations indicates that conditions on Mars may have been suitable for life in the past? |
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Definition
| There are dried up riverbeds on Mars. |
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Term
| Where are most of the known asteroids found? |
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Definition
| They are found between the orbits of Mars and Jupiter. |
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Term
| Where did the elements heavier than hydrogen and helium come from? |
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Definition
| They were produced inside stars. |
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Term
| Why did the solar nebula flatten into a disk? |
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Definition
| It flattened as a natural consequence of collisions between particles in the nebula, changing random motions into more orderly ones. |
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Term
| Which of the following lists the ingredients of the solar nebula from highest to lower percentage of mass of the nebula? |
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Definition
| Light gases (He, H), Hydrogen compounds (H20, CH4, NH3), rocks, metals. |
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Term
| What percentage of the solar nebula's mass consisted of hydrogen and helium gases? |
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Definition
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Term
| What kind of material in the solar nebula could remain solid at temperatures as high as 1,500K, such as existed in the inner regions of the nebula? |
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Definition
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Term
| The region of our solar system between Mercury and Mars has very few asteroids (made of rocks and metals), while the region between Mars and Jupiter has many asteroids. Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars? |
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Definition
| There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed. |
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Term
| Approximately how many other planetary systems have been discovered to date? |
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Definition
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Term
| Why are many of the newly detected extrasolar planets called "hot Jupiters"? |
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Definition
| Their masses are similar to Jupiter but they are very close to the central star and therefore hot. |
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Term
| How might our solar system be different if the frost line were farther out ? |
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Definition
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Term
| You discover that a nearby star, very similar to the Sun, has a velocity curve that has a period of 6 months, induced by the orbit of a planet. You infer that: |
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Definition
| The planet's orbit radius is less than 1 AU |
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Term
| The cores of the terrestrial worlds are made mostly of metal because |
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Definition
| Metals sunk to the centers a long time ago when the interiors were molten throughout. |
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Term
| Which of the following statements best explains why the planets orbit in nearly a single plane and in the same direction around the Sun? |
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Definition
| The planets formed from a disk of rotating gas. |
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Term
| Arrange the ingredients of Solar nebula from the most dominant to the least dominant |
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Definition
| Hydrogen and Helium, Hydrogen Compounds, Rock, Metals |
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Term
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Definition
| Its surface rocks were rusted by oxygen. |
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Term
| Which of the following worlds has the most substantial atmosphere? |
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Definition
| Venus > Mercury, the moon, Mars, Earth |
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Term
| Because of the Sun's magnetic field... |
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Definition
| The proto-Sun grew massive enough to hold it's volatiles by Gravitation despite the high temperature it reached. |
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Term
| What are greenhouse gases? |
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Definition
| Gases that absorb infrared light. |
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Term
| Which of the following statements about greenhouse gases is true? |
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Definition
A) Without the naturally occurring greenhouse effect, Earth would be too cold to have liquid oceans.
B) A weak greenhouse effect operates on Mars.
C) The burning of fossil fuels increases the greenhouse effect on Earth because of the release of carbon dioxide.
D) One result of an increased greenhouse effect on Earth may be an increased number of severe storms.
All are true. |
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Term
| Of the four fases CO2, H2O, N2, and O2, which are greenhouse gases? |
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Definition
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Term
| Why does the burning of fossil fuels increase the greenhouse effect on Earth? |
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Definition
| Burning releases carbon dioxide into the atmosphere. |
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Term
| Why is Mars so much colder than the Earth? |
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Definition
| Because Mars has a much thinner, more diffuse atmosphere. |
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Term
| Why is Venus so much hotter than the Earth? |
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Definition
| Because it has much more CO2 in it's atmosphere. |
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Term
| Why does increasing the amount a greenhouse gas increase the temperature of the planet? |
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Definition
| Greenhouse gases absorb infrared light. |
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Term
| The core of the Sun is... |
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Definition
| Much hotter and much denser than it's surface. |
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Term
| The sun is increasing in brightness as it ages, which affects Earth's climate. How much brighter is the Sun now than when it was born? |
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Definition
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Term
| What would happen in the Sun if the temperature of the core decreased? |
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Definition
| The fusion rate decreases, then the core shrink and heats. |
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Term
| According to modern science, approximately how old is the Sun? |
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Definition
|
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Term
| What is the Sun made of (by mass)? |
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Definition
| 70% hydrogen, 28% helium, 2% other elements. |
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Term
| Which of the following best describes why the Sun emits most of its energy in the form of visible light? |
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Definition
| Like all objects the Sun emits thermal radiation with a spectrum that depends on its temperature, and the Sun's surface temperature is just right for emitting mostly visible light. |
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Term
| A star's luminosity is the.. |
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Definition
| Total amount of energy that the star radiates each second. |
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Term
| If the distance between us and a star is doubles, with everything else remaining the same, its luminosity |
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Definition
| Remains the same, but its apparent brightness is decreased by a factor of four. |
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Term
| You measure the parallax angle for a star to be 0.5 arcseconds. The distance to this star is |
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Definition
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Term
| On a H-R diagram, where would you find the stars that are cool and luminous? |
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Definition
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Term
| On a H-R diagram, where would you find the white dwarfs? |
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Definition
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Term
| A star of spectral type G lives approximately how long on the main sequence? |
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Definition
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Term
| The age of stars in a cluster can be determined by... |
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Definition
| Determining the main sequence turnoff point. |
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Term
| Which star is the hottest star? |
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Definition
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Term
| Which main sequence star has the lowest mass? |
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Definition
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Term
| An O-star has a hotter surface temperature than the Sun. Therefore, compared to the Sun,... |
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Definition
| It's emission peaks in the blue part of the spectrum. |
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Term
| Compared to the star it evolved from, a red giant is.. |
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Definition
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Term
| Why does a star grow larger after it exhausts its core hydrogen supply? |
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Definition
| Hydrogen fusion in a shall outside the core generates enough thermal pressure to push the upper layers outward. |
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Term
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Definition
| The exposed core of a dead star, supported by electron degeneracy pressure. |
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Term
| After a massive-star supernova, what is left behind? |
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Definition
| Either a neutron star or a black hole. |
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Term
| From a theoretical standpoint, what is a pulsar? |
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Definition
| A rapidly rotating neutron star. |
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Term
| How does a black hole form from a massive star? |
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Definition
| During a supernova, if a star is massive enough for its gravity to overcome neutron degeneracy pressure in the core, the core will collapse to a black hole. |
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Term
| What is the diameter of the disk of the Milky Way? |
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Definition
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Term
| What kinds of objects lie in the disk of our galaxy? |
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Definition
Open clusters, O and B stars, K and M stars, gas and dust.
All of these are found. |
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Term
| Approximately how far is the Sun from the center of the galaxy? |
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Definition
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Term
| Compared to our Sun, most stars in the halo of our galaxy are.. |
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Definition
| Old, red, and dim and have fewer heavy elements. |
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Term
| Approximately how long does it take the Sun to orbit the center of the Milky Way Galaxy? |
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Definition
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Term
| Which of the following galaxies appear reddest in color? |
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Definition
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Term
| Compared to spiral galaxies, elliptical galaxies are.. |
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Definition
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Term
| Why are Cepheid variables important? |
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Definition
| Cepheid variables are pulsating stars whose pulsation periods are directly related to their true luminosities. Therefore they can be used as a distance indicators. |
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Term
| What is a standard candle? |
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Definition
| An object for which we are likely to know its true luminosity. |
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Term
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Definition
| The recession velocity of a galaxy is directly proportional to its distance. |
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Term
| Which of the following is a consequence of Hubble's Law? |
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Definition
| The more distant a galaxy is from us, the faster it moves away from us. |
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Term
| Why do we call dark matter, "dark"? |
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Definition
| It emits no or very little radiate of any wavelength. |
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Term
| What evidence suggests that the Milky Way contains dark matter? |
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Definition
| We observe matter far from the galactic center orbiting the galaxy at unexpectedly high speeds. |
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Term
| A gravitational lens occurs when.. |
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Definition
| A massive object bends light beams that are passing nearby. |
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Term
| Which of the following are candidates for galactic dark matter? |
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Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
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Term
| Which of the following best summarizes what we mean by dark energy? |
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Definition
| It is a name given to whatever is causing the expansion of the universe to accelerate with time. |
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Term
| When did earliest life forms appear on Earth? |
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Definition
|
|
Term
| When did the largest Mass extinction happen? |
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Definition
|
|
Term
| What do we mean by inflation? |
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Definition
| A sudden expansion of the universe driven by the energy released when the strong and electroweak forces froze out from the GUT force. |
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Term
| What defines the habitable zone around a star? |
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Definition
| The region around a star where liquid water can exist on planetary surfaces. |
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Term
| Which of the following are candidates for galactic dark matter? |
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Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
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|
Term
| Which of the following best summarizes what we mean by dark energy? |
|
Definition
| It is a name given to whatever is causing the expansion of the universe to accelerate with time. |
|
|
Term
| When did earliest life forms appear on Earth? |
|
Definition
|
|
Term
| When did the largest Mass extinction happen? |
|
Definition
|
|
Term
| What do we mean by inflation? |
|
Definition
| A sudden expansion of the universe driven by the energy released when the strong and electroweak forces froze out from the GUT force. |
|
|
Term
| What defines the habitable zone around a star? |
|
Definition
| The region around a star where liquid water can exist on planetary surfaces. |
|
|
Term
| Which of the following are candidates for galactic dark matter? |
|
Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
|
|
Term
| Which of the following best summarizes what we mean by dark energy? |
|
Definition
| It is a name given to whatever is causing the expansion of the universe to accelerate with time. |
|
|
Term
| When did earliest life forms appear on Earth? |
|
Definition
|
|
Term
| When did the largest Mass extinction happen? |
|
Definition
|
|
Term
| What do we mean by inflation? |
|
Definition
| A sudden expansion of the universe driven by the energy released when the strong and electroweak forces froze out from the GUT force. |
|
|
Term
| What defines the habitable zone around a star? |
|
Definition
| The region around a star where liquid water can exist on planetary surfaces. |
|
|
Term
| Which of the following are candidates for galactic dark matter? |
|
Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
|
|
Term
| Which of the following are candidates for galactic dark matter? |
|
Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
|
|
Term
| Which of the following are candidates for galactic dark matter? |
|
Definition
| Brown dwarfs, Juptier-size objects, WIMPs, Faint red stars. |
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