question

Originally, the signals that were found to be pulsars were thought to be

answer

little green men

question

If you replaced our sun with a one-solar mass black hole, Earth would

answer

maintain its orbit

question

The Schwarzchild radius of our sun is

answer

3 km

question

The maximum mas limit for a ___________ is 1.4 solar masses.

answer

white dward

question

If a stellar remnant is greater than 1.4 solar masses but less than about 3 solar masses, the resulting object will be a

answer

neutron star

question

If a stellar remnant is greater than 3 solar masses, the resulting object will be a

answer

black hole

question

At the event horizon, the escape velocity is equal to

answer

the speed of light

question

Who discovered the peculiar pattern of radio signals that were eventually found to be from a pulsar?

answer

Jocelyn Bell

question

Black hole candidates are detectable by their accretion disks producing mainly what type of light?

answer

X rays

question

The first X-ray binary suspected of harboring a black hole is

answer

Cygnus X-1

question

Objects in binary system consist of neutron star accumulating material from another star on its surface, where it ignites and produces periodic _____.

answer

X-ray bursters

question

When were neutron stars first predicted?

answer

1932

question

Of the following stars, the one that has the longest period of variability is

answer

the most luminous Cepheid

question

Compared to open star clusters, globular clusters tend to be

answer

poorer in metals and older

question

The 21-centimeter line of hydrogen is in the

answer

radio part of the spectrum

question

The galactic center of the Milky Way lies in the constellation of

answer

Sagittarius

question

The approximate diameter of the disk of the Milky Way Galaxy is

answer

75,000 light-years

question

In a typical spiral galaxy, stars in the

answer

halo have elliptical orbits

question

The supermassive black hole at the center of the galaxy is estimated to be

answer

2.6 million solar masses

question

What spectral classes of stars work best as spiral tracers?

answer

O and B

question

The youngest stars are

answer

Extreme Population I

question

Astronomers use the term "metals" to describe any element heavier than

answer

helium

question

A rotation curve measures

answer

orbital velocity vs. orbital radii

question

The 21-centimeter radiation is used to map the galaxy to detecting

answer

neutral (un-ionized) hydrogen

question

Which galactic region has the greatest metal content of stars

answer

spiral arms

question

The very center of the Milky Way Galaxy is invisible at what wavelengths?

answer

visible

question

Of the following objects, the one that must be a spiral galaxy is a

answer

Seyfert

question

The speed of a very highly redshifted quasar as determined by the relativistic Doppler formula is

answer

less than that determined by the classical formula

question

Of the following objects, the one that produces the least energy is a

answer

supernova

question

A BL Lac object is the same as a

answer

blazar

question

Because of the large look-back times of quasars, they appear as they were when the universe was only _____ percent of its present age.

answer

10

question

Most of the lines in the spectrum of the quasar 3C 273 are caused by

answer

Hydrogen

question

Quasar distances are estimated by

answer

their redshifts

question

Eruptions of supermassive black holes in quasars may have been caused by

answer

collisions or mergers with other galaxies

question

The objects that are detected at the points where the gas of a radio jet hits the extragalactic medium are called

answer

hot spots

question

The evidence leads modern astronomers to conclude that at the cores of active galaxies are supermassive black holes with masses as high as

answer

a billion solar masses

question

The universe has

answer

no edge and no center

question

The main reason the night sky is dark is that the universe is

answer

finite in age

question

Isotropy is the assumption that

answer

the universe looks the same in every direction

question

According to Hubble law, if Galaxy A is 10 times more distant than Galaxy B, then Galaxy A is

answer

receding 10 times faster than Galaxy B

question

The primordial background radiation is observable primarily at

answer

radio wavelengths

question

Of the following groupings of galaxies, the one that is the largest in size is the

answer

filaments and voids

question

The force that is NOT unified with the others in a Grand Unified Theory is the

answer

gravitational force

question

The type of universe in which the average density is predicted to be greatest is the

answer

closed universe

question

What did Arno Penzias and Robert Wilson initially think caused the background radiation in their microwave antenna

answer

pigeon droppings

question

The type of universe that will keep expanding forever is

answer

an open universe

question

A nuclear particle theory predicts the existence of massive particles that interact weakly with normal matter. These are all classified as

answer

MACHOs

question

The orbits of planets

answer

All lie in approximately the same plane

question

Each of the planets in our solar system orbits the sun

answer

in the same direction, counterclockwise as seen from the north (above)

question

The orbits of the planets lie mainly in the same plane because the planets

answer

formed from a large thin disk of material surrounding the new sun

question

The solar system has relatively little gas and dust between the planets. The lack of this material is probably the result of

answer

radiation pressure from the sun

question

The solar nebula theory describes how the planets formed from

answer

a disk-shaped cloud of gas and dust around the newly forming sun

question

The terrestrial planets near the sun are

answer

small, solid, and rocky.

question

The atmosphere of the Jovian planets are made primarily of

answer

Hydrogen and helium

question

Most asteroids revolve around the sun between the orbits of

answer

Mars and Jupiter

question

Objects made mostly of ice that form a large gaseous "tail" that is directed away from the sun at all times are called

answer

comets

question

Formation of planetesimals by condensation refers to the process of

answer

matter building one atom at a time

question

Solid particles sticking together to form larger particles describes the process of

answer

accretion

question

The separation of low-density and high density materials in a planet during the early stages of its formation is referred to as

answer

differentiation

question

The interiors of Jupiter and Saturn consist mostly of

answer

liquid hydrogen

question

Low-density and cold dust disks have been found around many stars. These disks are believed to be regions where planets have formed or are in the process of forming. The disks are most readily detected by

answer

infrared telescopes

question

A planet that has formed around the star 51 Pegasi has been detected by

answer

Doppler shifts in the star's spectrum as the planet orbits, causing the star to wobble back and forth

question

The source of comets is

answer

The Kuiper Belt and Oort Cloud

question

Our solar system may have a cold dusk disk similar to that found around the star Beta Pictoris. Astronomers believe that this disk is located in the ______ of objects.

answer

Kuiper Belt.

question

Iron and nickel drained to the center of Earth, while at the same time, the lighter silicates rose to the surface, and formed a thin crust. This process is known as

answer

differentiation

question

Which of the following sequences best describes the four-stage history of Earth's formation and evolution

answer

differentiation, cratering, basin flooding, surface evolution

question

Earth's core has a solid center and liquid outer parts. Evidence for the liquid component of the core comes from

answer

seismic wave studies

question

Between the crust and liquid core lies a solid material that behaves as a plastic, flowing under high pressure. This material makes up Earth's

answer

mantle

question

Earth's magnetic field is thought to result from the dynamo effect, which is

answer

motion in the liquid core that generates temperature currents

question

One of the best ways to locate the crustal plate boundaries is to identify

answer

the locations of earthquakes

question

The carbon dioxide in Earth's early atmosphere was produced when large amounts of gases were released during the accretion process when Earth's surface temperature was very hot. Most of the carbon dioxide remained in Earth's atmosphere until it was removed when

answer

Liquid water formed on Earth's surface and dissolved carbon dioxide causing it to react with other compounds to form limestone and other sediments

question

The form of electromagnetic radiation that the ozone layer prevents from reaching the Earth's surface is

answer

ultraviolet radiation

question

The temperature of Earth is much warmer and more uniform than it would be if Earth did not have an atmosphere. The gas most responsible for trapping heat in Earth's atmosphere is

answer

carbon dioxide

question

The greenhouse effect best describes the process by which

answer

heat is trapped by the atmosphere, thus increasing the temperature at a planet's surface

question

Free oxygen in Earth's atmosphere was produced by

answer

living organisms during photosynthesis

question

Large, reasonably flat and dark areas that cover a good portion of the side of the moon facing earth are referred to as lunar

answer

maria

question

The craters on the lunar surface were produced by

answer

impacts by asteroids and meteorites

question

Lunar rocks found in the highlands are

answer

rich in anorthocites, a light-colored-low density rock.

question

The core of the moon

answer

is small and contains little iron

question

The large-impact hypothesis proposes that the moon formed as a result of

answer

a Mars-sized object colliding with Earth and ejecting material from Earth's mantle, some of which fell back to Earth and the rest of which condensed to form the moon.

question

A problem with the fission hypothesis for the formation of the moon is

answer

the Earth-moon system has less angular momentum then would be expected from such a formation scenario

question

The craters on Mercury are the result of

answer

impacts of asteroids and meteorites

question

Lobate scarps on Mercury were probably caused by

answer

shrinkage of the surface as the interior of the planet cooled

question

Evidence of Mercury's iron core comes from

answer

unusually high overall density for a planet of its size

question

The weak (although stronger than expected) magnetic field around Mercury detected by the Mariner 10 spacecraft indicates

answer

the interior of the planet is similar to that of Earth

question

Spacecraft images of Venus offer little evidence for

answer

major plate motion

question

Analysis of the surface by spacecraft that have landed on Venus indicates that the surface material consists of

answer

basalt

question

The Magellan and Vanera spacecraft located similar features, called coronae, on the surface of Venus. These features are

answer

circular features probably caused by rising columns of magma under the crust

question

The major component of the atmosphere on Venus is

answer

carbon dioxide

question

The atmosphere of Venus contains more carbon dioxide than the atmosphere of Earth. This difference is probably the result of

answer

slightly warmer temperatures on Venus that prevented the accumulation of great amounts of liquid water, thus preventing carbon dioxide from dissolving into liquid water

question

Evidence of liquid water existing in the Martian past was found by the discovery of

answer

meandering drainage valleys and elongated flow features exposing ancient craters

question

Evidence of extensive volcanic activity on Mars is found in the

answer

Tharsis region in the northern hemisphere where there are numerous faults and lava flows

question

The polar caps of Mars consist of

answer

carbon dioxide and frozen water

question

The atmosphere of Mars consists primarily of

answer

carbon dioxide

question

The density of the atmosphere on Mars is about

answer

1% of Earth's atmosphere

question

The moons of Mars are

answer

Phobos and Deimos

question

The moons of Mars can briefly be described as

answer

irregular in shape with numerous surface craters

question

Rover Opportunity photographed small spheres of hematite in the rocks on Mars. These spheres indicate

answer

that liquid water was once present in standing pools at this location

question

Mar's atmosphere was much more dense in its past. Mars lost most of its atmosphere because

answer

its escape velocity is slow

question

The heavy bombardment era had the greatest influence on which stage of Earth's development

answer

flooding

question

As viewed through a telescope, Jupiter appears as a

answer

disk composed of various colored belts and bands

question

Saturn, as viewed through a telescope, appears as

answer

a bland and nearly featureless disk

question

Spacecraft photos revealed active volcanoes on the surface of Jupiter's moon

answer

Io

question

The grooved terrain on Ganymede is believed to be

answer

systems of faults in the brittle crust

question

The ring particles around Jupiter are very small, as evidenced by the observation that light

answer

scatters in the forward direction

question

The icy rings of Saturn are most likely not composed of particles left from the formation of the planet but rather

answer

debris from collisions between the heads of comets and and icy moons

question

The core of Jupiter is composed of

answer

heavy elements such as iron, nickel, and silicon

question

Jupiter's belts and bands are the result of atmospheric features that have been

answer

stretched and elongated as a result of Jupiter's rapid rotation.

question

The atmosphere of Titan is composed primarily of

answer

nitrogen

question

The Huygens probe to the surface of Titan revealed

answer

pebble-sized chunks of ice

question

The Cassini division is a large gap in the rings of Saturn. This gap is most likely produced by

answer

resonances between ring particles and the moon Mimas

question

Two small _____ interact gravitationally with wandering ring particles to keep Saturn's irregularly twisted F ring confined.

answer

shepherd satellites

question

Jupiter's Great Red Spot probably has an extended life because it

answer

originates from deep within the interior of Jupiter.

question

The belts and zones in the atmosphere of Saturn are less visible than those on Jupiter because

answer

they occur deeper in the cold atmosphere below a layer of methane.

question

Examination of photographs of Europa taken by the Galileo spacecraft in orbit around Jupiter support the conclusion that

answer

liquid water exists beneath the icy crust

question

Which of the following planets has its axis of rotation tipped the most

answer

Uranus

question

The discovery of Neptune was made as the result of

answer

predictions following mathematical calculations

question

The very bland appearance of the atmosphere of Uranus is probably caused by

answer

extremely cold temperatures and limited heat flow from its interior

question

Neptune's blue appearance is the result of the presence of

answer

methane

question

The rings of Neptune were discovered as the result of an occulation of a star by Neptune. Astronomers concluded that the rings were not complete because

answer

only one side of the planet yielded the exepected dimming of the starlight

question

The ring systems of Uranus and Neptune consist of very narrow rings. This narrowness is probably the result of

answer

shepherding satellites controlling the positions of the ring particles.

question

The oval patterns of grooves (ovoids) on the surface Uranus' moon Miranda is explained by

answer

internal heat that produced convection in the icy mantle

question

Dark smudges on the surface of Neptune's moon Titan appear to be

answer

Methane, converted by sunlight into dark deposits, ejected into space during the eruption of geysers of liquid nitrogen.

question

Pluto has characteristics that astronomers feel may link it and its moon to the

answer

Kuiper belt objects

question

The mass of Pluto was determined

answer

from the size of the orbit and period of its moon, Charon.

question

The Kuiper belt objects called Plutinos are in a 3:2 resonance with the planet Neptune. This means that

answer

These objects orbit the sun twice as Neptune orbits three times

question

Which of the following are classifications of meteorites

answer

iron and stony

question

Because of the delicate nature of the carbonaceous chondrites, it is believed that these meteorites came from planetistmals that

answer

orbited far from the sun in regions of the solar system that are very cold and are probably the least altered remains of the solar nebula

question

The iron meteorites probably formed from

answer

large planetesimals that melted and differentiated to form an iron core

question

Most often, a meteor is

answer

produced by tiny bits of debris from comets

question

A meteor shower occurs when

answer

Earth passes through the dust and bits of material left in the orbit of a passing comet

question

M-type asteroids appear to

answer

be made of iron-nickel alloy and are very bright

question

The formation of asteroids is the result of

answer

planetary material that never formed into large planets

question

Many collisions caused planetesimals to fragment into smaller pieces. These pieces probably make up the material known as

answer

meteorites

question

The solar wind directs the gas tail of a comet

answer

outward, away from the sun at all times

question

The nucleus of the coma contains mostly the ices of water, carbon dioxide, and ammonia. The coma is produced when the

answer

sun causes sufficient heating and the ices of the nucleus vaporize to produce a vast cloud of gas and dust

question

Studies show that the short-period comets cannot originate at a distance thousands of astronomical units from the sun. A closer source for short-period comets is the

answer

Kuiper belt

question

The spacecraft that intercepted Comet Halley in 1985 and 1986 discovered that the nucleus of Comet Halley is

answer

very dark and irregularly shaped

question

Jets of high speed gas are seen to be emitted from the nucleus of Comet Halley only

answer

from the sunlit side of the comet

question

Evidence that Earth has collided with an asteroid-sized object is suggested by a layer of the rare element

answer

iridium

question

The "smoking gun" crater that fits the description of the asteroid impact that may have caused the extinction of the dinosaurs was found

answer

Off the coast of the Yucatan peninsula

question

The basic unit of life as we know it is

answer

the cell

question

The element carbon is the physical basis for life on Earth. This atom

answer

is capable of bonding to other atoms and makes long, stable chains that are capable of extracting, storing, and utilizing energy

question

The information that enables the organism to survive and is transferred from parent to offspring is found in

answer

DNA

question

The info. a cell needs to function is found on the DNA molecule in the form of

answer

four bases and the order in which they appear

question

The info. regarding cell functioning is carried out of the nucleus by

answer

RNA

question

Evidence that life began in the oceans has been found in

answer

Cambrian period fossils

question

The Miller experiment consisted of various gases, believed to have been present in the early atmosphere of Earth, exposed to an electrical arc. This experiment resulted in

answer

amino acids, fatty acids, and urea

question

Hot stars, such as O and A stars, are unlikely to harbor planets suitable for sustaining life because

answer

their stable-energy producing lifespan is too short.

question

The region of space around a star in which water can remain in liquid form is called

answer

life (or habitability) zone

question

Scientists think Jupiter's moon Europa might be able to support life because

answer

there is evidence that below its ice surface there may be liquid water

question

Several meteorites found in Antarctica have been determined to come from Mars. The evidence for this conclusion lies in the

answer

analysis of trapped gases found in these meteorites with the same abundance as gases found in the Martian atmosphere

question

The Drake equation is used to

answer

estimate the number of technological civilizations within our galaxy

question

Of the following factors, the one that is a part of the Drake equation is the

answer

fraction of the lifetime of a star during which a technological civilization is capable of communicating.

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