The Universe and the Solar System Flashcards
how old is the universe?
at least 13.8 billion years old
how old is the earth/solar system?
at least 4.5-4.6 billion years old
the ______ as we currently know it compromises all space, time, matter, and energy in it
universe
the universe is made up of ______ (“ordinary” matter consisting of protons, electrons, and neutrons: atoms, planets, stars, galaxies, nebulae, and other bodies)
4.6% baryonic matter
the universe is made up of ______ (a source of antigravity)
71.4% dark energy
the universe is made up of ______ (matter that has gravity but does not emit light)
24% cold dark matter
this is a force that counteracts gravity and causes the universe to expand
dark energy
this matter can explain what may be holding galaxies together because the low total mass is insufficient for gravity alone to do so
dark matter
this energy can also explain the observed accelerating expansion of the universe
dark energy
in terms of chemical composition, the most abundant elements in the universe are _____ and _____.
hydrogen and helium
_______ that are common astronomical objects are the building blocks of galaxies born out of clouds of gas and dust
stars
a ______ is a cluster of billions of stars
galaxy
a cluster of galaxies form _______
superclusters
the two ways in which astronomers estimate the age of the universe:
- by estimating the age of the oldest looking stars; and
2. by measuring the rate of expansion of the universe and extrapolating back to the BIg Bang
the diameter of the universe is possibly infinite but should be at least ______
91 billion light years
the _______ is the leading explanation of how the universe began
the big bang theory
from time zero (13.8 billion years ago) until 10 seconds later, all matter and energy in the universe existed as a ________
hot, dense, and tiny state
about _______ years after the big bang, the solar system was formed
9.8 billion years
in 1929, Edwin Hubble announced his significant discovery of the “_______” and its interpretation that galaxies are moving away from each other, hence as evidence for an expanding universe, just as predicted by Einstein’s Theory of General Relativity
redshift
Edwin Hubble observed that spectral lines of starlight made to pass through a prism are shifted toward the red part of the electromagnetic spectrum, i.e., toward the band of the lower frequency; thus, the inference that the star or galaxy must be ________
moving away from us
the _______ compromises the sun, _______ planets, dwarf planets such as ________, satellites, asteroids, comets, other minor bodies such as those in the _______ belt and interplanetary dust.
solar system, eight, Pluto, Kuiper
the _______ lies between Mars and Jupiter
asteroid belt
________ are smaller asteroids
meteoroids
_________ are thought of as remnants of a “failed planet” - one that did not form due to disturbance from ______ gravity
meteoroids, Jupiter’s
the ________ belt lies beyond Neptune and compromises rocky or icy bodies a few meters to hundreds of kilometers in size.
Kuiper
the ______ clouds marks the _______ of the solar system and is composed of mostly icy objects
Oort, outer boundary
much of the mass (99.58%) of the solar system is concentrated at the ______ (Sun) while angular momentum is held by the _________.
center, outer planets
except for _____, ______, ________, and ______, the universe and the Earth have similar abundance, especially for rock and metal elements.
hydrogen, helium, inert gases, volatile
the sun and large planets have enough gravity to retain ______ and ______.
hydrogen, helium
________ are too light for the Earth’s gravity to retain, thus the low abundance
rare inert gases
the presence of heavy elements such as _____, _____, and ______, on earth suggests that it was derived from remnants of a supernova and that the sun is a _______ star made by recycling materials
lead, silver, uranium, second-generation
the ______ describes the formation of our solar system from a nebula cloud made from a collection of dust and gas
nebular hypothesis
the _______ suggests that a great cloud of gas and dust of at least 10,000 million kilometers in diameter rotated slowly in space about 5,000 million years ago
protoplanet theory
the _____ says that our planets and moons were wandering around in space and the planets were captured by the gravity of our sun, and the moons were captured by the planets.
capture theory
the capture theory was proposed by ______
michael mark woolfson
one of the earliest theories for the formation of the planets was called the _______.
encounter hypothesis
this hypothesis has the advantage of explaining why the planets all revolve in the same direction (from the encounter geometry) and provides an explanation for why the inner worlds are denser than the outer worlds
encounter hypothesis
