The Sun, Our Solar System, and Earth

Question 1

What is the asteroid belt and where is it located?

Answer 1

The region of the solar system in which most asteroids have their orbits, between Mars and Jupiter

Question 2

What is the chromosphere?

Answer 2

A region of the solar atmosphere between the bright photosphere and the more extensive corona. Hard to observe because of its relative faintness.

Question 3

What is the corona?

Answer 3

The outer (high-temperature) region of the solar atmosphere.

Question 4

What is a solar flare?

Answer 4

Rapid release of energy from a small region of the solar surface, observed as a sudden and localized brightening. Solar flares can emit cosmic rays as well as electromagnetic radiation.

Question 5

What does granulation mean?

Answer 5

Terrazzo-like appearance of solar photosphere when observed at high magnification.

Question 6

What is the heliocentric model and who invented it?

Answer 6

With the Sun at the center, as in the Copernican model for the solar system.

Question 7

What is the Oort cloud and where is it located?

Answer 7

Suggested reservoir of comets, located in a spherical region around the Sun and about 50,000 AU in radius

Question 8

What is the photosphere?

Answer 8

Bright apparent surface of a star from which most of the radiant energy is emitted. Not a solid surface but rather a region within the stellar (or solar) atmosphere

Question 9

What is a sunspot?

Answer 9

Area that appears dark on the solar disc because the sunspot has a temperature somewhat lower than its surroundings.

Question 10

What is the sunspot cycle?

Answer 10

11-year periodicity in the number of sunspots

Question 11

What are the terresterial planets?

Answer 11

Mercury, Venus, Earth, and Mars

Question 12

What are the Van Allen belts?

Answer 12

Regions around the Earth where the Earth?s magnetic field confines high-speed electrically charged particles, mostly protons and electrons.

Question 13

What is the aphelion?

Answer 13

In a noncircular orbit around the sun, the aphelion is the position where a planet is farthest from the sun. For a noncircular orbit around the Earth, the apogee is the position where a satellite is farthest from the Earth.

Question 14

What is an aroura?

Answer 14

Light emitted in the upper atmosphere in the far northern and southern latitudes. Produced by collisions of high-speed particles with atmospheric atoms and molecules, and strongly influenced by the Earth’s magnetic field and solar activity.

Question 15

What is the celestial equator?

Answer 15

Great circle formed on the celestial sphere by the extension out of the Earth’s equatorial plane

Question 16

What is the celestial sphere?

Answer 16

Apparent spherical surface, centered on the Earth to which the stars seem to be fixed.

Question 17

What is the core of a planet?

Answer 17

Central region of a planet. The Earth?s core is liquid, possible with a small, solid inner core.

Question 18

What is elongation?

Answer 18

Angle between the directions of a planet and the Sun, as viewed from the Earth.

Question 19

How often do equinoxes occur and what are they?

Answer 19

Two days each year when the Sun is above and below the horizon for equal lengths of time.

Question 20

What is the gegenschian?

Answer 20

Dim and hazy glow in the sky, seen in the direction opposite to the Sun, probably caused by sunlight reflected from many small dust particles.

Question 21

What is Earth’s ionosphere?

Answer 21

Outer region of the Earth’s atmosphere where many of the atoms have been ionized by the absorption of solar ultraviolet radiation.

Question 22

What are the Jovian planets in our solar system?

Answer 22

Jupiter, Saturn Uranus, and Neptune

Question 23

What is the meridian?

Answer 23

Great circle, on the celestial sphere or the Earth, that passes through both north and south poles and an observer’s zenith or location.

Question 24

What is the nadir?

Answer 24

The point opposite the zenith on the celestial sphere.

Question 25

What is the perigee?

Answer 25

Point in an Earth satellite?s orbit where it is closest to the center of the Earth.

Question 26

What is the perihelion?

Answer 26

Place in an orbit around the Sun which is closest to the center of the Sun. A term most frequently encountered in describing cometary orbits.

Question 27

What is a solstice?

Answer 27

Extreme positions reached by the Sun, north and south of the celestial equator. When the Sun is at these positions, the shadows it casts on the Earth?s surface are the longest or shortest (depending on whether you are making this observation in the northern or southern hemisphere).

Question 28

What is the stratosphere and where is it located?

Answer 28

One of the upper layers of the Earth?s atmosphere, above the troposphere that contains most of the weather, and below the ionosphere

Question 29

What does ecliptic mean in relation to the Sun and Stars?

Answer 29

Path that the Sun appears to follow, against the stars on the celestial sphere, during the course of a year.

Question 30

What is the ecliptic plane pertaining to the Earth and the Sun?

Answer 30

Plane defined by the Earth?s orbit around the Sun

Question 31

What is a limb? (as viewed from earth)

Answer 31

Edge of a bright object (Sun or planet) as viewed from Earth.

Question 32

What is the summer solstice?

Answer 32

Extreme northern position of the Sun on the celestial sphere, north of the celestial equator (summer refers to the northern hemisphere).

Question 33

What is the synodic period?

Answer 33

Time interval between successive repetitions of the same apparent positions of the Sun, Earth, and a body. Thus synodic period for a planet, or synodic month for the Moon.

Question 34

What is the troposphere?

Answer 34

Layer of the Earth?s atmosphere, from sea level to about 10-15 km. altitude, containing most of the weather.

Question 35

What is the winter solstice?

Answer 35

Extreme southern position of the Sun on the celestial sphere, south of the celestial equator (winter refers to the northern hemisphere).

Question 36

What is the zenith?

Answer 36

Point on the sky directly overhead.

Question 37

What is the zodiac?

Answer 37

Band on the sky, centered on the ecliptic, and about 18 degrees wide, through which the Sun, Moon and planets appear to move through the course of each year.

Question 38

What are the Galilean satellites?

Answer 38

Four satellites of Jupiter discovered by Galileo who first named them Medicean satellites, after Cosimo de Medci, his patron.

Question 39

What are the Magnetic poles?

Answer 39

One of the two regions on Earth to which a compass needle will point.