The Universe and the Solar System

Question 1

how old is the universe?

Answer 1

at least 13.8 billion years old

Question 2

how old is the earth/solar system?

Answer 2

at least 4.5-4.6 billion years old

Question 3

the ______ as we currently know it compromises all space, time, matter, and energy in it

Answer 3

universe

Question 4

the universe is made up of ______ (“ordinary” matter consisting of protons, electrons, and neutrons: atoms, planets, stars, galaxies, nebulae, and other bodies)

Answer 4

4.6% baryonic matter

Question 5

the universe is made up of ______ (a source of antigravity)

Answer 5

71.4% dark energy

Question 6

the universe is made up of ______ (matter that has gravity but does not emit light)

Answer 6

24% cold dark matter

Question 7

this is a force that counteracts gravity and causes the universe to expand

Answer 7

dark energy

Question 8

this matter can explain what may be holding galaxies together because the low total mass is insufficient for gravity alone to do so

Answer 8

dark matter

Question 9

this energy can also explain the observed accelerating expansion of the universe

Answer 9

dark energy

Question 10

in terms of chemical composition, the most abundant elements in the universe are _____ and _____.

Answer 10

hydrogen and helium

Question 11

_______ that are common astronomical objects are the building blocks of galaxies born out of clouds of gas and dust

Answer 11

stars

Question 12

a ______ is a cluster of billions of stars

Answer 12

galaxy

Question 13

a cluster of galaxies form _______

Answer 13

superclusters

Question 14

the two ways in which astronomers estimate the age of the universe:

Answer 14

1. 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

Question 15

the diameter of the universe is possibly infinite but should be at least ______

Answer 15

91 billion light years

Question 16

the _______ is the leading explanation of how the universe began

Answer 16

the big bang theory

Question 17

from time zero (13.8 billion years ago) until 10 seconds later, all matter and energy in the universe existed as a ________

Answer 17

hot, dense, and tiny state

Question 18

about _______ years after the big bang, the solar system was formed

Answer 18

9.8 billion years

Question 19

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

Answer 19

redshift

Question 20

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 ________

Answer 20

moving away from us

Question 21

the _______ compromises the sun, _______ planets, dwarf planets such as ________, satellites, asteroids, comets, other minor bodies such as those in the _______ belt and interplanetary dust.

Answer 21

solar system, eight, Pluto, Kuiper

Question 22

the _______ lies between Mars and Jupiter

Answer 22

asteroid belt

Question 23

________ are smaller asteroids

Answer 23

meteoroids

Question 24

_________ are thought of as remnants of a “failed planet” - one that did not form due to disturbance from ______ gravity

Answer 24

meteoroids, Jupiter’s

Question 25

the ________ belt lies beyond Neptune and compromises rocky or icy bodies a few meters to hundreds of kilometers in size.

Answer 25

Kuiper

Question 26

the ______ clouds marks the _______ of the solar system and is composed of mostly icy objects

Answer 26

Oort, outer boundary

Question 27

much of the mass (99.58%) of the solar system is concentrated at the ______ (Sun) while angular momentum is held by the _________.

Answer 27

center, outer planets

Question 28

except for _____, ______, ________, and ______, the universe and the Earth have similar abundance, especially for rock and metal elements.

Answer 28

hydrogen, helium, inert gases, volatile

Question 29

the sun and large planets have enough gravity to retain ______ and ______.

Answer 29

hydrogen, helium

Question 30

________ are too light for the Earth’s gravity to retain, thus the low abundance

Answer 30

rare inert gases

Question 31

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

Answer 31

lead, silver, uranium, second-generation

Question 32

the ______ describes the formation of our solar system from a nebula cloud made from a collection of dust and gas

Answer 32

nebular hypothesis

Question 33

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

Answer 33

protoplanet theory

Question 34

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.

Answer 34

capture theory

Question 35

the capture theory was proposed by ______

Answer 35

michael mark woolfson

Question 36

one of the earliest theories for the formation of the planets was called the _______.

Answer 36

encounter hypothesis

Question 37

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

Answer 37

encounter hypothesis