Astronomy Chapter 7 Vocab

retrograde rotation

All eight planets in the Solar System orbit the Sun in the direction that the Sun is rotating, which is counterclockwise when viewed from above the Sun's north pole. Six of the planets also rotate about their axis in this same direction. The exceptions—the planets with ___________ —are Venus and Uranus.

what is the greenhouse effect and what role does it play in the atmospheres of venus and Earth?

It is the heating of a surface caused by the presence of certain gases that absorb infrared radiation. They trap heat in the atmosphere especially in Venus and Earth because of their thick atmospheres (carbon dioxide)

Why is Mars red?

It's surface materials are composed of iron-rich minerals that are reddish brown in color

why is mercury so difficult to observe? when is the best time to see the planet

Its maximum greatest elongation is only about 28 degrees which means it is very close to the horizon when the sky is dark. the best time to observe it is within a few days of its greatest elongation

Which planet is least likely to have water ice on or just under its surface?

Mercury

Compare the surfaces of Mercury and our moon. Similarities and differences?

Mercury lacks extensive crater-less regions and instead has relatively small craters. There are dormant volcanoes on Mercury and none on the moon. Mercury and the moon have exceptionally low albedos.

compare the interiors of mercury and Earth.. similarities and differences?

Mercury's average density is similar to Earth's caused by their dense interiors. Mercury is the most iron-rich planet in the solar system, only Earth's greater mass- greater pressure- contributes to a slightly higher density than Mercury. They both have magnetic fields surrounding the planet.

briefly describe a scientific theory explaining why mercury has such a large iron core

One theory is that mercury crashed into another planet and combined cores to make Mercury's large core

southern highlands

Sparsely cratered plains on mars

why is it hotter on venus than on mercury?

The greenhouse effect which traps the heat inside. the atmosphere is acting like a thermal blanket

Which pair of planets have atmospheres with the most similar chemical compositions?

Venus and Mars. both have around 95% carbon dioxide but the key difference is that venus' atmospheric pressure is 90 times that of Earth's while mar's atmospheric pressure is .06 times Earth's.

hot-spot volcanism

a process by which molten rock rises to the surface from a fixed hot region far below

northern vastness (northern lowlands)

broad northern plains on mars

The olympus Caldera

consists of overlapping volcanic craters. The volcano is wreathed in mid-morning clouds brought upslope by cool air currents. located on Mars

dust devil

during the afternoons, heat from the planets (mars) surface warms the air and sometimes creates whirlwinds called ____

greenhouse effect

is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be in the absence of its atmosphere. If a planet's atmosphere contains radiatively active gases

3-to-spin-orbit coupling

mercury undergoes three sidereal rotations every two years

during which configuration of planets is it easiest to observe Mars from Earth?

opposition because it is up all night and its closest to earth.

which object is most similar to venus in mass and diameter?

the Earth