Exam Questions on Planets and the Sun

Venus

gets so bright as to be seen in daylight at times.

Mercury

shows the widest range of surface temperatures between day and night.

Venus' rotation

is clockwise, unlike most other solar system objects.

Mercury's surface

most resembles the lunar far side.

Atmospheric pressure on Venus

is much higher than on Earth.

Main constituent of the atmosphere of Venus

is carbon dioxide.

Main constituent of the Martian atmosphere

is carbon dioxide.

Water on Mars

is thought to be in a layer of permafrost just below the surface.

Planet with the widest range of surface temperatures

is Mercury.

Planet with the least variation in temperatures

is Venus.

Planet with axial tilt and rotation period most like our own

is Earth.

Spacecraft Cassini

went into orbit around Saturn.

Jovian planet with the largest axial tilt

is Uranus.

Reason jovian planets lost little of their original atmosphere

is due to their large mass.

Great Red Spot

is a large cyclonic storm (hurricane).

Alternating zones of gas in Jupiter's atmosphere

create light and dark bands.

Great Dark Spot

A storm on Neptune observed in 1989 that had disappeared by 1995.

Brightness of Jupiter

Jupiter is second in brightness only to Venus most of the time.

Cause of Io's volcanoes

Thought to be caused by gravitational tidal stresses from both Jupiter and Europa.

Densest and most geologically active Galilean moon

Io.

Galilean moons of Jupiter

The four are Io, Europa, Ganymede, and Callisto.

Surface of Europa

Most resembles the Earth's Arctic Ocean.

Moon with the densest atmosphere

Titan.

Moons of interest to exobiologists

Europa and Enceladus are considered most interesting.

Galilean moon of most interest to exobiologists

Europa.

Lakes on Titan

Made mostly of liquid methane.

Huygens probe landing

Successfully landed on Titan.

Statistic changed most in the last decade

The number of known Jovian moons.

Year Pluto was discovered

Pluto was discovered in 1930.

Unusual aspect of Pluto's orbit

It is more inclined to the ecliptic than any of the eight planets.

Temperature of the photosphere

About 5,800 K.

Energy transport mechanisms in the Sun

In order from outside the core to the surface: radiation; convection.

core

The innermost layer of the Sun where nuclear fusion occurs.

photosphere

The visible surface layer of the Sun that emits light.

radiative zone

The layer of the Sun where energy is transferred outward by radiation.

corona

The outermost layer of the Sun's atmosphere, visible during a solar eclipse.

convective zone

The layer of the Sun where energy is transferred by convection.

chromosphere

The layer of the Sun's atmosphere above the photosphere, visible during eclipses.

granulation

The pattern of hot convective cells rising in the photosphere.

sunspot cycle

A cycle that lasts about 11 years, during which the number of sunspots increases and decreases.

sunspots

Dark splotches on the Sun that are cooler than the surrounding areas.

proton-proton cycle

The fusion process in stars that converts hydrogen into helium.

critical temperature for proton-proton cycle

10 million K, the temperature required to initiate the proton-proton cycle.

lost mass in proton-proton cycle

It is converted to energy according to Einstein's equation E=mc².

primary source of the Sun's energy

The strong force fusing hydrogen into helium in the core.

solar wind

A stream of charged particles released from the corona.

coronal energy

Most is in the form of X-rays.

prominence

A loop or sheet of gas hanging above an active region of the Sun.

strongest magnetic fields in the photosphere

Lie near sunspots.

solar flare

A sudden, violent disruption around sunspots releasing energy in almost all wavelengths.

Mars volcanoes

Mars has larger volcanoes than Earth's Hawaii.

water on Mars

There is new evidence that water has flowed as mud on Mars in recent times.

running water on Mars

Played a major role in shaping Mars in ancient times.

spacecraft visits to planets

Not all nine planets in the solar system have been visited by spacecraft.

differential rotation

When a planet's equatorial and polar regions rotate at different rates.

jovian planets rotation

All four jovian planets spin faster than any of the terrestrials.