Science Flashcards

Front 1

radio telescope

Back 1

An instrument used to detect radio emissions from the sky, whether from natural celestial objects or from artificial satellites.

Front 2

refracting telescope

Back 2

A telescope that uses a converging lens to collect light.

Front 3

reflecting telescope

Back 3

A telescope in which a mirror is used to collect and focus light.

Front 4

electromagnetic spectrum

Back 4

the range of wavelengths or frequencies over which electromagnetic radiation extends.

Front 5

Mars

Back 5

Mars orbits between earth and Jupiter at an average distance of 141.6 million miles (228 million km) from the sun, and has an equatorial diameter of 4,208 miles (6,787 km). Its characteristic red color arises from the iron-rich minerals covering its surface. There is a tenuous atmosphere of carbon dioxide, and the seasonal polar caps are mainly of frozen carbon dioxide. Unambiguous evidence of life has yet to be found. There are two small satellites, Phobos and Deimos.

Front 6

Mercury

Back 6

Mercury orbits within the orbit of Venus at an average distance of 36 million miles (57.9 million km) from the sun. With a diameter of 3,031 miles (4,878 km), it is only a third larger than earth's moon, which it resembles in having a heavily cratered surface. Its ‘day’ (equivalent to 58.65 Earth days) is precisely two thirds the length of its ‘year’ (87.97 Earth days). Daytime temperatures average 338°F (170°C). There is no atmosphere and the planet has no satellites.

Front 7

meteorite

Back 7

a meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground. More than 90 percent of meteorites are of rock, while the remainder consist wholly or partly of iron and nickel

Front 8

observatory

Back 8

an astronomical telescope or other scientific equipment for the study of natural phenomena.
a position or building affording an extensive view.

Front 9

Venus

Back 9

Venus orbits between Mercury and the earth at an average distance of 67.2 million miles (108 million km) from the sun. It is almost equal in size to the earth, with a diameter of 7,521 miles (12,104 km) and shows phases similar to the moon. The planet is completely covered by clouds consisting chiefly of sulfuric acid droplets, and no surface detail can be seen by telescope. There is a dense atmosphere of carbon dioxide, which traps the heat of the sun by the greenhouse effect to produce a surface temperature of 460°C. The planet has no natural satellite.

Front 10

Saturn

Back 10

Saturn orbits between Jupiter and Uranus at an average distance of 887 million miles (1,427 million km) from the sun. It is a gas giant with an equatorial diameter of 74,600 miles (120,000 km), with a conspicuous ring system extending out to a distance twice as great.The planet has a dense, hydrogen-rich atmosphere similar to that of Jupiter but with less distinct banding. There are at least eighteen satellites, the largest of which is Titan, and including small shepherd satellites that orbit close to two of the rings.

Front 11

solstice

Back 11

either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.

Front 12

solar eclipse

Back 12

an eclipse in which the sun is obscured by the moon.

Front 13

lunar eclipse

Back 13

an eclipse in which the moon appears darkened as it passes into the earth's shadow.

Front 14

comet

Back 14

Originating in the remotest regions of the solar system, most comets follow regular eccentric orbits and appear in the inner solar system as periodic comets, some of which break up and can be the origin of annual meteor showers. They were formerly considered to be supernatural omens.

Front 15

space shuttle

Back 15

a rocket-launched spacecraft, able to land like an unpowered aircraft, used to make repeated journeys between the earth and earth orbit.

Front 16

asteroid

Back 16

a small rocky body orbiting the sun. Large numbers of these, ranging in size from nearly 600 miles (1,000 km) across (Ceres) to dust particles, are found (as the asteroid belt) esp. between the orbits of Mars and Jupiter, though some have more eccentric orbits, and a few pass close to the earth or enter the atmosphere as meteors.

Front 17

equinox

Back 17

the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length (about September 22 and March 20).

Front 18

orbit

Back 18

the state of being on or moving in such a course

Front 19

solar system

Back 19

the collection of nine planets and their moons in orbit around the sun, together with smaller bodies in the form of asteroids, meteoroids, and comets.

Front 20

Neptune

Back 20

Neptune orbits between Uranus and Pluto at an average distance of 2,794 million miles (4,497 million km) from the sun (but temporarily outside the orbit of Pluto 1979–99). It is the fourth largest planet, with an equatorial diameter of 30,200 miles (48,600 km), and the most remote of the gas giants.The planet is predominantly blue, with an upper atmosphere mainly of hydrogen and helium with some methane. It has at least eight satellites, the largest of which is Triton, and a faint ring system.