the sun, moon and five bright "stars" that the Greeks called wanderers; any of the celestial bodies (other than comets or satellites) that revolve around the sun in the solar system, a body that revolves around a star
Planet -- Greek definiiton
What are the names of the planets?
Mercury, Venus, Mars, Jupiter, Saturn, Earth, Uranus, Neptune, and Pluto - the dwarf planet
Oval or egg shaped orbit, An orbit that is long and flat.
a closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it, A regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.
a fixed reference point on the concave side of a conic section
irregular; odd -- due to being flattened by being farther apart
discovered that the paths of the planets around the sun are elliptical rather that circular, Assistant to Brahe; used Brahe's data to prove that the earth moved in an elliptical, not circular, orbit; Wrote 3 laws of planetary motion based on mechanical relationships and accurately predicted movements of planets in a sun-centered universe; Demolished old systems of Aristotle and Ptolemy
Kepler's 3 Laws of Planetary Motion
1) Planets did not rotate in perfect circles 2) The closer the planet is to the sun the faster it moves 3) The larger the planet the slower it moves
when a planet is closest to the sun; nearest point to the sun in the orbit of a planet or comet
the point in a planet's orbit that is farthest from the sun
a unit of length used for distances within the solar system, The average distance between Earth and the sun, about 150 million kilometers (ua)
the fraction of solar radiation that is reflected off the surface of an object, Percent of light reflected after striking a surface., is the fraction of total radiation that is reflectged by any surface
the measure of the amount of matter a planet contains -- related to weight but NOT the same thing
the vertical force exerted by a mass as a result of gravity
Can an object be "weightless" and still have mass?
Yes, object in interstellar space is weightless due to lack of gravity, but still has mass
is determined by a planet's size and mass; The downward pull the planet exerts on objects at its surface
the SI unit of force, a unit of force equal to the force that imparts an acceleration of 1 m/sec/sec to a mass of 1 kilogram; STANDARD METRIC UNIT OF FORCE AND WEIGHT
What do the nine planets vary in from planet to planet?
mass, surface gravity, and density
mass divided by volume, the amount of matter in a given space
How did ancient Greeks recognize that the planets were different from stars?
because the planets moved -- thus were called wanderers -- while stars remained in a fixed location
List the 9 planets in order from the sun outward? (MVEMJSUNP)
most vegetarians eat mostly Juicy salads under new plants --- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
What are the similarities of the planet's orbits?
all planets stay close to an ecliptic orbit -- the sun's apparent path through the stars; the planet's orbit almost in the same plane -- with the exception of pluto -- its orbit is quite different with an inclination of about 17 % from the ecliptic
What is the term for the point in a planet's orbit when it is nearest the sun?
What is the term for the point in a planet's orbit when it is farthest the sun?
What is the measure of a planet's ability to reflect light called?
What 3 factors affect the apparent magnitude of a planet?
distance from the earth, the ability of the surface or atmosphere of the planet to reflect light (albedo), and the size of the planet
What 2 factors determine a planet's surface gravity?
a planet's size and mass
Why could an objects weigth vary on two different planets of the same size? (discusssion question)
this is due to the surface gravity of individual planets. Surface gravity is determined by the planets size and mass. Therefore, in two extreme cases -- Pluto and Jupiter -- on Pluto the object would weigh only 6 % of its weight on earth - BUT on Jupiter the same object would weigh 2.53 times more than the Earth weight
Does the planet with the most mass also have the highest density -- yes or no -- and why?
no because density is the mass of a material or object in a single volume unit of the material -- a given volume of rock is heavier than the same volume of weight -- mass is different based upon what the object is made or composed of
Venus and Mercury, so called because their orbits are smaller (closer to the Sun) than Earth's.
the changing shapes in the appearance of the moon
planet passes directly between the earth and the sun so that we see its dark silhovette against the suns bright disk
Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto --these are the planets whose orbits are farther from the sun than the Earth's orbit
planets sometimes appear to temporarily reverse their direction of motion (as when the Earth passes a superior planet)
The name given to the four inner planets: Mercury, Venus, Earth, and Mars, the four planets that have rocky surfaces. They all have rocky crusts and dense mantles and cores.
The name given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune, very large planets that don't have any known solid surfaces, the large, gaseous planets of the outer solar system, planets made up mostly of substances that would be gases on Earth
What is the difference between a superior planet and an inferior planet?
Superior planets are larger and closer to the Earth than the sun; inferior planets are smaller and are closer to the sun than the Earth
Explain what happens in a transit by an inferior planet?
like the moon they show phases and they undergo transits -- when that planet passes directly between the Earth and the sun
Which planets undergo transits as viewed from the Earth?
Mercury and Venus
What name is given to the apparent backward motion of a slower-moving superior planet as the earth passes it?
any of the four outermost planets in the solar system, the Jupiter like planets; Jupiter, Saturn, Uranus, and Neptune. These planets have relatively low densities and are huge gas giants
What is a terrestrial planet?
planets that are the earth's size or smaller and have about the same density as the earth -- these ppanets resemble the earth in size and density -- BUT are different in one respect -- the Earth has oxygen in its atmosphere and liquid water on its surface -- other terrestrial planets have neither of these things
Can inferior planets undergo retrograde motion -- and why or why not?
no, inferior planets can NOT undergo retrograde motion -- this only takes place with the slower-moving superior planets
the smallest planet and the nearest to the sun, closest planet to the sun, 2nd smallest planet, closest to the Sun; does not have a true atmosphere; has a surface with many craters and high cliffs
Probe that flew by Venus and Mercury and gave us pictures of Venus' clouds and Mecury's cratered surface
In the 1970s this probe gave us pictures of Jupiter and Saturn
satellite that studied Mars in 1975-76; this probe explored the environment on Mars, Mars probe that detected marsquakes.
launched in 1997; Mission that went to the gas giants, Jupiter and Saturn
1990 probe sent to study solar system; mapped out the cloud-cover of Venus with radar 100 times more powerful than that of Pioneer
Italian astronomer and mathematician who was the first to use a telescope to study the stars; 1989 probe of Jupiter
the second nearest planet to the sun, similar to earth in size and mass, second planet from the Sun; similar to Earth in mass and size; has a thick atmosphere and a surface with craters, faultlike cracks, and volcanoes, the brightest planet in the sky
the 4th planet from the sun, fourth planet from the Sun; has polar ice caps, a thin atmosphere, and a reddish appearance caused by iron oxide in weathered rocks and soil, The red planet, has the solar system's largest volcano - olympus mons, 2 moons - phobos and deimos
the largest planet and the 5th from the sun, largest and fifth planet from the Sun; contains more mass than all the other planets combined, has continuous storms of high-pressure gas, and an atmosphere mostly of hydrogen and helium, atmosphere of hydrogen and helium, The great red spot, a giant hurricane like storm, is on this planet
a giant planet which is surrounded by three planar concentric rings of ice particles, second-largest and sixth planet from the Sun; has a complex ring system, at least 31 moons, and a thick atmosphere made mostly of hydrogen and helium, atmosphere of hydrogen, helium, amnonia, methane, water vapor, 31 moons - titan
large gap between the two largest rings of Saturn caused by the gravitational pull of the moon, Mimas
a giant planet with a ring of ice particles, seventh planet from the Sun; is large and gaseous, has a distinct bluish-green color, and rotates on an axis nearly parallel to the plane of its orbit
usually the eighth planet from the Sun; is large and gaseous, has rings that vary in thickness, and is bluish-green in color, active storms rapidly change the atmosphere, 11 moons - tritan, blue-green atmosphere
the second smallest planet and the farthest known from the sun, dwarf planet, considered to be the ninth planet from the Sun; has a solid icy-rock surface and a single moon, Charon, thin atmosphere - icy surface