MidTerm Answers Flashcards

1
Q

The greatest triumph of Newton’s theory of gravity was

A

Its ability to mathematically predict all 3 of Kepler’s laws

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which sentence best describes how Rømer first measured the speed of light?

A

He predicted when Jupiter’s moons would be behind the planet, and compared to observed time ½yr apart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

A scientific theory can be shown to be wrong if:

A

scientists gather new data that contradicts its predictions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When an electron moves from a higher energy level in an atom to a lower energy level:

A

a photon is emitted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Light from the Moon takes about how long to reach Earth?

A

1 second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are good reasons to put an telescope in Earth’s orbit?

A

to observe at wavelengths blocked by Earth’s atmosphere; to avoid light pollution; to avoid weather; to avoid atmospheric distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The ancients observed and recorded the motions of the Sun, Moon and Planets in the sky primarily for:

A

Religion, keeping time, charting seasons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The visible light spectrum from the Sun shows which of the following features?

A

Absorption lines and Continuum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

EM radiation in order of decreasing wavelength (largest to smallest)?

A

Radio waves, infrared, visible, ultraviolet, X-rays.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which principle does a telescope with lenses make use of to create a focus point?

A

Refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which one of Galileo’s observations directly refuted the Ptolemaic mode of the Universe?

A

the phases of Venus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How did Kepler fix the “Great Martian catastrophe”?

A

By correctly positioning the Earth’s orbit relative to the Sun in Copernicus’ heliocentric model of the universe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

For northern latitudes, the day that the Sun is seen lowest in the southern half of the sky marks the

A

winter solstice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

During the formation of a planetary system why does a spinning cloud begin to spin faster as it collapses?

A

The cloud rotates faster to conserve the angular momentum it had when it was larger & spinning slower.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

If the moon is new and is on the ecliptic, what would we see from Earth?

A

A total or annular Solar eclipse.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Earth doesn’t experience an eclipse of the Sun every month because

A

the moon’s orbit is not in the same plane as the Earth’s orbit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which condition below is true for a total Solar eclipse?

A

The Moon must be new and on the ecliptic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

If you are lucky enough to see a total solar eclipse, you must be standing in the:

A

Moon’s umbra.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which best describes where in the sky the Sun (and hence the ecliptic) is during the
spring equinox?

A

The Sun (and the ecliptic) is 0 away from the equator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why are the seasons on Mars so similar to those on Earth?

A

Mars rotation axis is tilted with respect to its orbital plane by the same amount as Earth’s.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Like Mars and Venus, Earth originally had a lot of carbon dioxide in its atmosphere. Where is the majority of the carbon now?

A

It is bound up in rocks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Mars, Venus and the Earth are much less heavily cratered than Mercury or the Moon. This is explained by the fact that:

A

Mars, Venus and Earth were geologically active for a longer period of time than Mercury or the Moon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When was the most recent (i.e. youngest) crater on the moon’s surface made?

A

Today!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

At what point in its appearance in the sky is Mars furthest from the Earth?

A

Conjunction

25
Q

What is the most direct cause of the temperature increase in the North hemisphere’s summer season, as compared to winter?

A

Sunlight strikes the ground most directly and hence each square meter receives more energy during summer.

26
Q

If the Sun is just setting, and the Moon is full that night, the Moon will be

A

just on or above the eastern horizon.

27
Q

What is the precession period of the Earth’s rotational axis?

A

26000 years

28
Q

From where did planetary geologists get their oldest samples of the moon’s surface?

A

The lunar highlands.

29
Q

The Moon’s phases cycle with its:

A

synodic period

30
Q

The difference in composition between the giant planets and the terrestrial planets is most like caused by the fact that:

A

the terrestrial planets are closer to the Sun.

31
Q

The ______ is the imaginary line that divides eastern and western halves of the sky for an observer.

A

meridian

32
Q

What happens to the kinetic energy (energy of motion) of cloud of gas as it falls toward and eventually hits the accretion disk surrounding a protostar?

A

It is converted into thermal energy, heating the disk.

33
Q

Why is it not possible to ever see a planet directly overhead (at the zenith) in Brandon?

A

The planets follow the ecliptic and the maximum distance the ecliptic is above the southern horizon is 23½o + 40o which does not equal 90o.

34
Q

Besides producing spectacular observational evidence for the Solar Nebula Theory, what else did astronomers learn from the recent ALMA image of protoplanetary disk surrounding the protostar HL Tauri?

A

Planets may form faster than previously thought.

35
Q

Angular sizes ordered smallest to largest:

A

1 arcsecond, 1 arcminute, 1 degree.

36
Q

What two variables go into Newton’s formulation of gravity?

A

mass and distance

37
Q

The observational data that Kepler used to compare his model of the planets’ motions to came from

A

Tycho Brahe’s naked-eye observations

38
Q

Light from the Sun takes how long to reach Earth?

A

8 minutes

39
Q

Which formula denotes how the speed of light c is related to its wavelength λ (metres) and frequency f (1/seconds)?

A

c=λf

40
Q

Looking down on the Solar System, the geometric arrangement of Mercury, the Earth and the Sun when Mercury is at greatest elongation in our sky is?

A

a right-angle triangle

41
Q

Which formation theory of the Moon was most supported by moon rocks returned by the manned lunar missions in the ‘70’s?

A

The collisional ejection theory

42
Q

Which star will be our pole star in 12,000 years?

A

Vega

43
Q

What defines a planet?

A

orbits around the sun; a nearly spherical shape; has cleared the neighborhood around its orbit

44
Q

What are Mars’ two moons?

A

Phobos and Deimos

45
Q

What are Jupiter’s four Galilean moons?

A

Io, Europa, Ganymede, Callisto

46
Q

When last was Saturn’s rings viewed edge-on?

A

2009

47
Q

What is meant by recombination?

A

An electron recombines with an atom, the atom emits light

48
Q

What is meant by ionization?

A

An electron is ejected, absorbs light, becomes “ionized”

49
Q

Which two are the most important measures of a telescope’s power?

A

Light-gathering power and Resolving power

50
Q

What do objective lenses or mirrors accomplish?

A

gathers light and bends it into focus

51
Q

What does an eyepiece do?

A

brings the bright image from the focus and magnifies it to the size of your eye’s pupil

52
Q

Which two telescope properties determine the instrument’s angular resolution?

A

Diameter and Wavelength of observation

53
Q

What information does the albedo of a planet’s surface tells us?

A

the variation of types of rocks across the surface: dark volcano rocks have low albedo, more reflective and brighter rocks have higher albedo

54
Q

What is special about the opposition of Mars?

A

Mars is closest to Earth, and appears large enough that telescopes can see remarkable detail!

55
Q

A lunar eclipse occurs when __________ shadow falls on__________.

A

Earth’s; the Moon

56
Q

What does light-gathering power mean for a telescope?

A

the number of photons a telescope can collect simultaneously

57
Q

What does the resolving power mean in a telescope?

A

the smallest angular size the telescope can separate and image distinctly

58
Q

What are the two basic designs of telescopes?

A

Refractors (lens) and Reflectors (mirrors)