Earth Sci | 1Q Flashcards
Ptolemy created a model of the universe that accounted for the movement of the planets.
Ptolemaic System
the apparent westward motion of the planets with respect to the stars
Retrograde motion
He concluded that Earth is a planet
Nicolaus Copernicus
designed and built instruments to measure the locations of the heavenly bodies
Tycho Brahe
He discovered three laws of planetary motion
Johannes Kepler
an oval-shaped path
ellipse
the average distance between Earth and the sun; it is about 150 million kilometers
astronomical unit (AU)
His most important contributions were his descriptions of the behavior of moving objects
Galileo Galilei
Although others had theorized the existence of gravitational force, Newton was the first to formulate and test the law of universal gravitation
Sir Isaac Newton
Gravitational force decreases with distance
universal gravitation
The two main motions of Earth are..
rotation and revolution
a third and very slow motion of Earth’s axis
Precession
the turning, or spinning, of a body on its axis.
Rotation
Two measurements for rotation:
Mean solar day
Sidereal day
the motion of a body, such as a planet or moon, along a path around some point in space
Revolution
the time in January when Earth is closest to the sun
Perihelion
is the time in July when Earth is farthest from the sun
Aphelion
is the time interval from one noon to the next, about 24 hours
Mean solar day
is the time it takes for Earth to make one complete rotation (360º) with respect to a star other than the sun—23 hours, 56 minutes, 4 seconds
Sidereal day
traces out a cone over a period of 26,000 years
Precession
the point at which the moon is closest to Earth
Perigee
the point at which the moon is farthest from Earth
Apogee
occur when the moon moves in a line directly between Earth and the sun, casting a shadow on Earth
Solar eclipses
occur when the moon passes through Earth’s shadow.
Lunar eclipses
the depression at the summit of a volcano or a depression produced by a meteorite impact
crater
Most of the lunar surface is made up of densely pitted, light-colored areas
Highlands
any of a system of bright, elongated streaks, sometimes associated with a crater on the moon
Rays
ancient beds of basaltic lava, originated when asteroids punctured the lunar surface, letting magma bleed out
Maria
a long channel associated with lunar maria. A rille looks similar to a valley or a trench
rille
a thin, gray layer on the surface of the moon, consisting of loosely compacted, fragmented material believed to have been formed by repeated impacts of meteorites
lunar regolith
are planets that are small and rocky—Mercury, Venus, Earth, and Mars
terrestrial planets
are the huge gas giants—Jupiter, Saturn, Uranus, and Neptune
Jovian planets
a cloud of gas and/or dust in space
nebula
The substances that make up the planets are divided into three groups:
gases, rocks, and ices
are small, irregularly shaped bodies formed by colliding matter
Planetesimals
is the innermost and second smallest planet; it is hardly larger than Earth’s moon
Mercury
has cratered highlands, much like the moon, and vast smooth terrains that resemble maria
Mercury
has the greatest temperature extremes of any planet
Mercury
The Veiled Planet
Venus
is similar to Earth in size, density, mass, and location in the solar system. Thus, it has been referred to as “Earth’s twin.”
Venus
The Red Planet
Mars
is covered in thick clouds that visible light cannot penetrate
Venus
has only 1 percent of the density of Earth’s
Mars
its atmosphere is very thin, extensive dust storms occur and may cause the color changes observed from Earth
Mars
has a mass that is 2 1/2 times greater than the mass of all the other planets and moons combined
Jupiter
Giant Among Planets
Jupiter
how many moons does Jupiter have?
28 moons
The Elegant Planet
saturn
its atmosphere is very active, with winds roaring at up to 1500 kilometers per hour
saturn
how many moons does saturn have
31 moons
is the largest moon, and it is bigger than Mercury
Titan
The Sideways Planet
Uranus
its axis of rotation lies nearly parallel with the plane of its orbit
Uranus
The Windy Planet
neptune
Planet X
Pluto
its orbit is highly eccentric, causing it to occasionally travel inside the orbit of Neptune, where it resided from 1979 through February 1999
Pluto
is a small, rocky body whose diameter can range from a few hundred kilometers to less than a kilometer
asteroid
are small bodies made of rocky and metallic pieces held together by frozen gases
comets
generally revolve about the sun in elongated orbits
comets
is the fuzzy, gaseous component of a comet’s head
coma
The most famous short-period comet; Its orbital period is 76 years
halley’s comet
Comets with long orbital periods appear to be distributed in all directions from the sun, forming a spherical shell around the solar system
Oort Cloud
move in nearly circular orbits that lie roughly in the same plane as the planets
kuiper belt
a small, solid particle that travels through space
meteoroid
is the luminous phenomenon observed when a meteoroid enters Earth’s atmosphere and burns up, popularly called a shooting star
meteor
is any portion of a meteoroid that reaches Earth’s surface
meteorite
the region of the sun that radiates energy to space, or the visible surface of the sun
photosphere
It consists of a layer of incandescent gas less than 500 kilometers thick
photosphere
a grainy texture made up of many small, bright markings
granules
the first layer of the solar atmosphere found directly above the photosphere
chromosphere
It is a relatively thin, hot layer of incandescent gases a few thousand kilometers thick
chromosphere
the outer, weak layer of the solar atmosphere
chromosphere
a stream of protons and electrons ejected at high speed from the solar corona
solar wind
a dark spot on the sun that is cool in contrast to the surrounding photosphere
sunspot
are huge cloudlike structures consisting of chromospheric gases
Prominences
are ionized gases trapped by magnetic fields that extend from regions of intense solar activity
Prominences
are brief outbursts that normally last about an hour and appear as a sudden brightening of the region above a sunspot cluster
Solar flares
the result of solar flares, are bright displays of ever-changing light caused by solar radiation interacting with the upper atmosphere in the region of the poles
Auroras
is the way that the sun produces energy. This reaction converts four hydrogen nuclei into the nucleus of a helium atom, releasing a tremendous amount of energy
Nuclear fusion
a star of extremely high density composed entirely of neutrons
neutron star
a star that has exhausted most or all of its nuclear fuel and has collapsed to a very small size, believed to be near its final stage of evolution
white dwarf
are thought to be remnants of supernova events
neutron star
a source that radiates short bursts or pulses of radio energy in very regular periods
A pulsar
a massive star that has collapsed to such a small volume that its gravity prevents the escape of everything, including light
black hol
a group of stars, dust, and gases held together by gravity
A galaxy
a large spiral galaxy whose disk is about 100,000 light-years wide and about 10,000 light-years thick at the nucleus
The Milky Way
reveal that the Milky Way has at least three distinct spiral arms, with some splintering
Radio telescopes
a system of galaxies containing several to thousands of member galaxies
Galaxy Clusters
a Doppler shift toward the red end of the spectrum, occurs because the light waves are “stretched,” which shows that Earth and the source are moving away from each other
Red Shifts
a law that states that the galaxies are retreating from the Milky Way at a speed that is proportional to their distance
Hubble’s law
theory states that at one time, the entire universe was confined to a dense, hot, supermassive ball
The big bang theory
