pattern of direct and retrograde motion of a planet as it moved slowly against the background
The purpose of describing planetary orbits in terms of epicycles and deferents was to account for the..
An elliptical orbit with the sun at one focus
Kepler's first law states that a planet moves around the sun in..
Exactly one half
How much of the overall sky is north of the celestial equator, in the northern hemisphere?
change in apparent position of a nearby object as the observer moves
The phenomenon of parallax is the
velocity with time
Acceleration of a moving body is defined as the rate of change of
If the earth's spin axis were perpendicular to the Earth's orbital plane then the seasons and seasonal variation would be
10 to the 0 power is
length, the average distance between the sun and earth
An astronomical uni or 1 AU is a unit of
a geocentric model of the solar system
ecliptic and the celestial equator
The equinoxes are located at the intersections of the
right ascension and declination
The celestial coordinates that together describe a star's position precisely and unambiguously are
The word planet is derived from a Greek term meaning
sunrise or sunset
A full moon will be on the horizon at
distance that light travels in one year
One light year is the
westward motion against the star background
Retrograde motion of a planet is
entire universe is governed by a single set of fundamental physics laws
An underlying theme of astronomy is that the
Suppose that an object is discovered moving around the Sun every 120 years. Which of the following paths is a possible orbit for this object?
time over which the moon completes one orbit around Earth, relative to the stars
The term "sidereal month" refers to the
the slow coning motion of the spin axis of the Earth, similar to that of a spinning top
observer's latitude (north or south of the equator)
For an observer at a fixed location on the Earth, the angle between the north celestial pole and an observer's horizon depends on the
Which of the following lines or points is always directly over your head, no matter where on earth you go?
An arcsecond is a measure of
10 times that on Earth due to the sun
Suppose that a planet of 10 times the mass of Earth were orbiting the Sun at the same distance as Earth (1 AU). The gravitational force on this planet due to the sun would be
Who was the first astronomer to use a telescope for viewing the sky?
the square of the orbital period is directly proportional to the cube of its mean distance from the sun
Kepler's third law states that
When the moon is between the Sun and the Earth and the Sun and Moon are almost in line, we call its phase
At what point in its orbit is a comet closest to the Sun?
The apparent path of the Sun across our sky, day by day, throughout the year, is known as the
5 * 105
The number five hundred thousand is written in powers-of-ten notation as
always keeps the same side toward the Earth
In its orbit around the Earth, the Moon
What is the phase of the moon during a total solar eclipse
What is the approximate inclination of the Moon's orbit to the ecliptic plane?
Earth exerts a force on you as you stand on its surface. What is the size of the force exerted on Earth by you, when compared to the above force?
arc joining the north and south celestial poles through the observer's zenith
An observer's celestial (local) meridian is the
Waxing crescent, first quarter, waxing gibbous, full moon
Which of the following is the correct sequence of appearances of Moon phases in the sky?
made accurate measurements of planetary positions, which Kepler later used to find the shapes of the planetary orbits
88 regions of the sky, covering the entire sky
In modern astronomy, the constellations are
Ursa Major, the Big Dipper
The constellation whose stars are used as pointers to the north celestial pole in the northern hemisphere is
rotation of the Earth on its axis
The nightly motion of objects across our sky is caused by the
Sun-centered with planets moving in perfect circles around the sun
The early Copernican system of planetary motion is
grinding the mirror to a parabolic shape
Spherical aberration can be corrected in a reflecting telescope by
Compared to its speed in a vacuum (or in space) the speed of light in glass is
amount of energy emitted by each square meter of the star's surface each second
The energy flux F from a star is the
lambda max T = constant
Wien's law, relating to the peak wavelength lambda max of light emitted by a dense object to its temperature, T, can be represented by
a black body, perfect absorber and emitter of energy at all wavelengths
The Stefan-Boltzmann law relating energy per unit area F emitted by an object to its temperature T, F=oT4, is obeyed ideally by what type of object?
as both waves and particles, depending on the type of interaction
In its interaction with matter, light behaves
The main optical element in a refracting telescope is a
same number of protons but different numbers of neutrons
Isotopes of a particular element in the periodic table have which nuclear property in common?
The change in direction of a light ray as it crosses from a less dense, transparent material to a more dense one
What is the refraction of light?
its total mass divided by its volume
The mean density of a planet is
Chunks of ice that begin to vaporize if they pass close to the sun
Comets are typically
They produce their own characteristic pattern of spectral lines, which remain fixed as the temperature increases
The early workers in spectroscopy discovered which very significant fact about the spectra produced by hot gases, such as elements heated in a flame?
The core is made of material far denser than the surface rock
The Earth has an average density of 5500 kg/m3 , whereas the density of rock on its surface is about 3000 kg/m3 . What conclusion can be reached about the Earth''s core from this observation?
In our solar system, which of the following planets is not a member of the terrestrial group?
The seven largest satellites in the solar system in their size and physical characteristics most resemble
electric and magnetic fields, always inseparable, always having the same frequency and wavelength, and traveling in the same direction
Electromagnetic radiation moving through space with the speed of light consists of oscillating
release of heat by collisions of particles as they gain kinetic energy in falling toward the center of the nebula
What process heated the early solar nebula as it slowly condensed toward a central protosun?
When a solid body is heated to a temperature T, the total radiated energy flux F from the body per second per unit area is given by
composed mainly of very light elements, such as H and He
The low average densities of the Jovian planets, which have high masses and hence high gravitational fields, is an indication that their interiors are
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
The correct sequence of planets in our solar system from the sun outward is
accretion of planetesimals to form a core, followed by gravitational capture of hydrogen and helium gas
The steps in the process of formation of the large outer planets were
is larger if the wavelength is shorter
In comparing photons of different wavelengths, we find that the energy carried by a photon
James Clerk Maxwell
Who was the first person to suggest that light is an electromagnetic wave?
a rotation axis that tilts only slightly with respect to the ecliptic
All of the following conditions except one appear to be necessary in order for a planet or satellite to produce a planet-wide magnetic field by the dynamo effect. Which is the exception?
a very narrow range
In the full wavelength of electromagnetic radiation, visible light occupies what proportion of the possible range
nuclei of atoms
Most of the mass of ordinary matter resides in the
four small planets close to the sun, four large planets far from the sun, and one small planet farthest from the sun
The main characteristics of our solar system are
electrons jumping to lower energy levels, losing energy as they do so
The specific colors of light emitted by an atom in a hot, thin gas are caused by
area of its primary mirror or lens
The light gathering power of a telescope is related directly to the
At the speed of light 3 * 108 m/s
Radio waves travel through space at what speed?
thermonuclear fusion reactions began at its center
The protosun became a full fledged star when
The outermost planet, Pluto, does not fit easily into either one of these groups
A theory of origin of the solar system must take into account all important general properties of the planets. These include three of the four properties listed below. Which one is not an important general property of the planets?
UV, visible, IR, radio
Choose the correct sequence of electromagnetic radiations, in order of increasing wavelengths
changes from the infrared to the visible wavelengths
As a new star evolves from cool dust and gas to a hot star, the peak wavelength of its spectrum of electromagnetic radiation
r is equal to i
In the reflection of a beam of light from a flat surface, the relationship between the angle of incidence i between the perpendicular to the surface and the incident beam and the angle of reflection r between the perpendicular and the reflected beam is
the shortest-wavelength electromagnetic waves
In terms of wavelengths, gamma rays are
One concave and one flat mirror
A Newtonian telescope consists of which of the following combinations of optical elements?
Which is the largest planet in our solar system
Between infrared and ultraviolet
Visible light occupies which position in the whole electromagnetic spectrum?
hydrogen, smaller quantities of helium, and very small quantities of heavier elements
The most common elements in the universe are
is very similar to a reflecting optical telescope
A radio telescope
Which of the following types of telescope will suffer from chromatic aberration unless very expensive measures are taken to avoid it?
number of protons in the nucleus of the atom
The atomic number that designates the position of an element in the periodic table is equal to the
the wavelength of light is shifted to a shorter wavelength if the source of light is moving toward you
According to the Doppler effect,
Identical to each other if the blackbodies are at the same temperatures but not otherwise
Two physicists, one in Australia, the other in the United States, find that each has constructed an ideal blackbody...
reflects no light and emits light in a manner determined by its temperature
A blackbody is an idealized object that
close to the density of water
The average density of the massive Jovian planets is
Negatively charged electrons moving around a very small but massive, positively charged core
The physical structure of an atom is
The temperature scale most often used by scientists is the
Bombardment by interplanetary meteoritic material
Most of the craters on the Moon were formed by
the opposite direction to Earth but very slowly
Venus rotates in
Titan is Saturn's largest satellite. It is unusual among all the planetary moons because of its
four-layered - a rocky inner core, a liquid outer core of "ices", a mantle of liquid hydrogen and helium, and an extensive gaseous atmosphere
The overall interior structure of Jupiter and Saturn is expected to be
droplets of H2SO4 or sulfuric acid
The clouds in the atmosphere of Venus consist primarily of
A large object collided with Earth and ejected the material that formed the moon
The theory that seems to account most satisfactorily for the origin of the Moon at the present time is that
an oblate spheroid with its spin axis shorter than its equatorial diameter because of its rapid spin
The three-dimensional shape of Jupiter is
a little longer than 24 hours, in the same direction as Earth
The period and direction of rotation of mars are
the sinking of heavier elements toward the center of a planet and the floating of lighter elements towards the surface
"Chemical differentiation" in planetary science refers to
Which satellite of Jupiter is volcanically active?
dense iron core taking up almost half of the volume of the planet and a rocky mantle surrounding the core
The internal structure of Mercury is a
ancient lava floodplains
a volcano on Mars
Olympus Mons is
Two tectonic plates are slowly spreading apart
The Mid-Atlantic Ridge in Earth's crust is a region where
Which planet has wide, bright rings that are easily visible from Earth?
solidified quickly on the surface of the Moon, as shown by gas bubbles frozen into the rock
The dominant rock type found on the Lunar Maria
1:2:4 - Europa takes twice as long to orbit Jupiter as Io, and Ganymede takes twice as long as Europa, but there is no simple integer relationship between Calisto and Ganymede
What is the relationship between the orbital periods of the four Galilean Satellites of Jupiter?
regions at different latitudes appear to rotate at different rates
The interesting feature of Jupiter's rotation is that
water ice or rock coated with water ice
The particles in Saturn's rings are composed of
Solid iron inner core, molten iron outer core, rocky mantle, lighter rocky crust
What is the basic structure of Earth's interior?
The ionized gas tail of a comet is always aligned with the
a wide, dark gap in Saturn's rings
What is the Cassini division?
Distinct evidence of the flow of water at an earlier time is seen on photographs of which planetary body?
nitrogen - N2
The major constituent of the atmosphere of Titan (largest moon of Saturn) is
a relatively young, icy crust, covered with a network of streaks and cracks, and only a few impact craters
Europa, one of the Galilean satellites of Jupiter, has a surface consisting of
produces gigantic volcanoes on Venus and Mars but produces chains of Volcanoes on Earth (e.g. the Hawaiian Islands)
Hot-spot volcanism is a process that
occasional strong winds and dust storms
A major feature of the atmosphere of Mars is
a large, long-lived, high-pressure storm in Jupiter's atmosphere
The Great Red Spot is
The Martian atmosphere is very thin and traps less infrared radiation from the surface
The greenhouse effect, which heats a planet's surface above the predicted equilibrium surface temperature for the planet without an atmosphere, is far less effective on Mars than on the Earth. Why is this?
The major constituent of Saturn is
About 1 month
How long is a "lunar day" or the time between two successive sunrises or sunsets on the moon?
absorption of atmospheric gases of infrared radiation emitted by a planet that has been heated by solar visible and ultraviolet radiation
The greenhouse effect is
layer of fine powder covering the lunar surface
The lunar regolith is the
a large rift valley system associate with the great volcanoes on Mars
What is Valles Marineris
gravitational potential energy released as heat during its formation stages, still being released
The source of excess heat emitted by Jupiter, above that which is absorbed as sunlight and reemitted is thought to be
tidal disorientation by Jupiter and its other moons
The heating of the interior of the large Galilean moon Io of Jupiter, in order to produce volcanic activity, is probably caused by
The four major moons of Jupiter are collectively named after which early astronomer?
Which of the planets fits the following description: "A hot solid surface, cloud-shrouded, with a dense CO2 atmosphere?"
region beyond the atmosphere, where the magnetic field protects us from solar wind
Earth's magnetosphere is the
Carbon dioxide ice
The "snow" that occasionally falls upon Mars and covers the bottoms of craters is most probably made of
The one terrestrial planet that rotates in the "wrong" direction (opposite to the planet's direction of revolution around the sun) is
Io, the inner Galilean moon of Jupiter
The most active volcanic object in the solar system is