ASTR 129 Exam Chap 2 & 3

At latitude 50 degrees North, the celestial equator crosses the meridian at altitude:

40 degrees in the South

Which of the following is not true about a scientific theory?

A theory is essentially an educated guess.

Earth is closer to the Sun in January than in July. Therefore, in accord with Kepler's second law:

Earth travels faster in its orbit around the Sun in January than in July.

Which of the following was not a major advantage of Copernicus's Sun-centered model over the Ptolemaic model?

It made significantly better predictions of planetary positions in our sky

According to Kepler's third law:

Jupiter orbits the Sun at a faster speed than Saturn.

Two stars that are in the same constellation:

May actually be very far from each other

A newly discovered planet orbits a distant star with the same mass as the Sun at an average distance of 106 million kilometers. Its orbital eccentricity is 0.4. Part A: Find the planet's orbital period. Part B: Find the planets nearest orbital distance from its star Part C: Find the planet's farthest orbital distance from its star

Part A: 7.16 months Part B: 0.43 AU Part C: 0.99 AU

Part A: The dwarf planet Eris orbits the Sun every 557 years. What its average distance (semi major axis) from the Sun? Part B: How does its average distance compare to that of Pluto?

Part A: Eris's semi major axis = 67.7 AU Part B: aEris/aPluto = 1.72

Halley's comet orbits the Sun every 76.0 years and has an orbital eccentricity of 0.97 . Part A: Find its semi major axis distance. Part B: Find its perihelion distance. Part C: Find its aphelion distance. Part D: Does Halley's comet spend most of its time near its perihelion distance, its aphelion distance, or halfway between?

Part A: Semi major axis distance = 17.9 AU Part B: 0.537 AU Part C: 35.3 AU Part D: Near its aphelion distance

Part A: The Shadow cast by a simple stick or obelisk allowed ancient people to: Part B: Why wasn't the sun-centered model of Copernicus immediately adopted after he proposed it? Part C: An original observation of Galileo's that helped to overturn the ancient Earth-centered model was: Part D: Which of the following are the three key hallmarks of science? (3)

Part A: Tell the time of day Part B: It was not noticeably more accurate than the old Ptolemaic model Part C: The phases of Venus Part D: 1) science progresses through the creation and testing of models of nature that explain the observations as simply as possible. 2) models must make testable predictions that will force us to revise or abandon the model if they do not agree with observations. 3) modern science seeks explanations for observed phenomena that rely solely on natural causes

Part A: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the March and September equinoxes. Part B: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the summer (June) solstice. Part C: Choose the correct description of the path of the Sun at a latitude of 40 degrees North for the winter (December) solstice

Part A: The sun rises due east, reaches an altitude of 50 degrees South on the meridian, and sets due west Part B: On the June solstice, the Sun rises more than 23.5 degrees north of due east, reaches an altitude of 73.5 degrees on the meridian in the south, and sets more than 23.5 degrees north of due west. Part C: On the December solstice, the Sun rises more than 23.5 degrees south of due east, reaches an altitude of 26.5 degrees on the meridian in the south, and sets more than 23.5 south of due west.

In winter, Earth's axis points toward the star Polaris. In spring, the axis points toward...

Polaris

What does the fact that we always see the same face of the Moon tells us about?

The Moon rotates with the same period that it orbits Earth

Summarize the development of the Greek geocentric model through Ptolemy. How did the Ptolemaic model account for apparent retrograde motion?

The Ptolemaic model was able to explain retrograde motion by having the planets move backward on their circular orbits on which they went around Earth

In the Greek geocentric model, the retrograde motion of a planet occurs when:

The planet actually goes backward in its orbit around Earth

Beijing and Philly have about the same latitude but different longitudes. What can be said about the tonight's night sky in these two places?

The sky will look about the same.

Last night I saw Jupiter right in the middle of the Big Dipper. (Hint: Is the Big Dipper part of the Zodiac?) Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false)

The statement does NOT make sense because Jupiter, like all the planets, is always found very close to the ecliptic in the sky. The ecliptic passes through the constellations of the zodiac, so Jupiter can only appear to be in one of the zodiac constellations - and the Big Dipper is not part of the zodiac.

I live in the United States, and during my first trip to Argentina I saw many constellations that I'd never seen before. Choose the correct explanation why the statement makes sense (or is clearly true) or does not make sense (or is clearly false)

This statement makes sense, because the constellations visible in the sky depend on latitude. Since Argentina is in the Southern Hemisphere, the constellations visible there include many that are not visible from the U.S.

When it is summer in Australia, the season in the United States is...

Winter

The South Celestial pole is 40 degrees above your Southern Horizon. What does it tell you?

You're at latitude 40 degrees South

At the North Pole on the summer solstice, the Sun:

circles the horizon at altitude 23 1/2 degrees

Tycho Brahe's contribution to astronomy included:

collecting data that enabled Kepler to discover the laws of planetary motion.

A star's path through your sky depends on your latitude and the star's:

declination

A star that is located 30 degrees north of the celestial equator has:

declination = 30 degrees

When we say that a planet has a highly eccentric orbit, we mean that:

in some parts of its orbit it is much closer to the Sun than in other parts.

If the Sun rises precisely due east,

it must be the day of either the spring or fall equinox

Galileo's contribution to astronomy included:

making observations and conducting experiments that dispelled scientific objections to the Sun-centered model.

If there is going to be a total lunar eclipse tonight, then you know that:

the Moon's phase is full

A week after full moon, the Moon's phase is:

third quarter