One light year is the

distance that light travels in one year

10

Which planet is not visible to the naked eye?

Neptune

The point directly above your head in the sky is referred to as the

Zenith

Polaris is different from other stars because

It never moves, it can be used to determine direction and latitude

The moon's angular diameter in our sky is measured to be half a degree. From this we can find

The diameter of the moon if we know the moon's distance

Within 23.5 degrees of the equator in latitude-- the tropics

Precession is

The slow wobbling motion of the spin axis of the earth, similar to that of a spinning top

What is the sequence of appearances of moon phases in the sky?

New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent

What time of the year will your shadow in sunlight at midday be shortest?

The first day of summer (around June 21st)

Scientific results from NASA's Kepler mission suggest that

Earth size planets in the habitable zone around their stars may in fact be rather common

The coordinate system that astronomers use to define the positions of objects on the celestial sphere uses

Right ascension and declination

Why is it far more likely that a person will have seen a total lunar eclipse rather than a total solar eclipse?

A total lunar eclipse can be seen by people on most of the nighttime side of earth whereas a specific total solar eclipse can only be seen by people within a narrow strip of the earth's surface

To see the greatest number of stars possible throughout the period of one year, a person should be located at latitude

0 degrees (at the equator)

Ecuador is Spanish for equator. It's Sept 21 and you're in the capitol, Quito. At local noon, how many degrees above the horizon is the sun?

90

Imagine a planet whose rotation axis is perpendicular to its orbital plane (it has no tilt) How would you describe the seasons?

It has no seasons

Stars that never appear to set are called circumpolar. As you move from the earth's equator toward the north pole the number of circumpolar stars

increases

How does the moon rotate to keep one face pointed toward the earth at all times?

It rotates once per month

What causes winter to be cooler than summer?

Daylight period is longer in summer and the sun gets higher

Shift toward the north

The sidereal day (a full rotation of the earth measured relative to distant stars) is 4 minutes shorter than a solar day. If earth's spin were in the opposite direction then a sidereal day...

Would be longer than a solar day

You want to construct a model of the solar system on a football field with the sun on one goal line and pluto on the other goal line (100 yds away) If the true distance between the sun and pluto is 5.9*10^9 km, what scale factor is needed to fit the solar system into a football field?

5.9*10^7 km/yd

If the earth is located at a distance of 150 million km from the sun, on what yard line should you place the earth to keep its distance from the sun to scale?

the 3 yd line

The phenomenon of the parallax is the

Change in apparent position of a nearby object as the observer moves

According to Kepler's third law, an asteroid orbiting the sun in a circular orbit at 3x the earth's distance from the sun would have a sidereal period of

5.2 years

What's the significance of Galieleo's observation that Jupiter has moons?

It showed that bodies can orbit an object other than earth

At which point in a planet's elliptical orbit is it closest to the sun?

Perihelion

Weight

Suppose that a planet of the same mass as earth was orbiting the sun at a distance of 5 AU

1/25 of the gravitational force the sun exerts on earth

The water on the side of earth that faces away from the moon experiences

A high tide because the moon in effect pulls the solid earth out from under the water on the far side

The moon has less mass than the earth and therefore it exerts

The same force on the earth as the earth exerts on it

In the 1860s, James Clerk Maxwell derived a famous set of mathematical equations that descreibed electromagnetic waves that could have different wavelengths. These waves, which include visible light, have since been shown to

Have no wavelength limit, either short or long

What is the wavelength of radiation emitted by an AM radio station transmitting at a frequency of 1000 kHz?

300 m

How do the speeds of radio waves and gamma rays compare?

They both travel at the same speed, the speed of light

Which of the following correctly ranks the energy content of E-M waves, from lowest to highest energy?

Radio, visible, UV, X-ray

Rings have been discovered

On all four of the Jovian planets

As a general rule

Older surfaces are more heavily cratered than younger surfaces

A rotation axis that tilts only slightly with respect to the ecliptic

In general large bodies in the solar system show less evidence of cratering than do small bodies. Why should we expect this correlation?

Large bodies cool more slowly and are more likely to retain internal heat and be geologically active, capable of resurfacing the planet and obliterating craters

Elements heavier than hydrogen and helium made up what fraction of the solar nebula?

2%

11,460 years

What is the basic difference between comets and asteroids?

Comets are mostly composed of ices while asteroids are mainly composed of rocks

As the solar nebula contracted it spun _______ and ________

Faster, heated up

The terrestial planets formed closer to the sun than the jovian planets because

The condensation temperature of rock-forming materials is higher, so this material condensed nearer the sun than did the lighter gases

What is surprising about the extrasolar planets that have been discovered to date?

Many of them are giant planets like Jupiter, orbiting at distances characteristic of terrestrial planets

What theory about the origin of the moon is now believed to be correct?

An object about the size of Mars crashed into earth and debris from the collision formed the moon

Star forming regions in a spiral galaxy such as the milky way are typically found

in the spiral arms