Earth Sun and Solar Eclipse – Astronomy Chapter 1

Earth Sun and Solar Eclipse –

In this chapter, we discuss Solar eclipse, sun, earth, stars and other celestial bodies.


A solar eclipse can happen only during a…

A. Full moon
B. perihelion passage of the sun
C. First quater moon
D. solstice
E. New Moon – Correct


The fact that the earth has moved along its orbit in the time it took to rotate once is the reason for.

A. Seasons
B. The difference between solar and sidereal time – Correct
C. Precession
D. The position of the celestial equator
E. Earths 23.5 degree tilt


The celestial sphere is divided into 88 modern constellations.
True or false

True

A star with a declination of +60 degrees will be
A. East of the vernal equinox
B. South of the celestial equator
C. West of the vernal equinox
D. North of the celestial equator – Correct


That polaris will not always be the pole star is due to.
A.the sidereal day being shorter than the solar day.
B.the Moon following the ecliptic, instead of the equator.
C. precession shifting the celestial pole. correct
D.the Earth’s revolution being slightly less than exactly 365.25 days.
E. the Solar winds blowing the Earth farther away from the Sun


In 1 second, light leaving Los Angeles reaches approximately as far as:

The moon, 384000km


Which correctly lists things in order from largest to smallest?

Universe, Local Group, Milky Way, Solar System.


About how many stars are visible on a clear, dark night with the naked eye alone?

A few thousand


Into how many constellations is the celestial sphere divided?

88


What are constellations?

Groups of stars making an apparent pattern in the celestial sphere


Where on earth would you be if Polaris was at your zenith?

North Pole


The vernal equinox is now just entering the constellation Aquarius. In what constellation will it lie in the year 10,000AD?

Scorpius


If Taurus is now rising at sunset, which constellation will rise at sunset next month?

Gemini


Suppose that instead of being inclined to Earth’s orbit around the Sun, the Moon’s orbit was in the same plane as Earth’s orbit around the Sun. In this hypothetical situation, approximately how many solar eclipses would occur each year?

12


The actual number of solar eclipses that occur each year is approximately:

2


What conditions must exist for a solar eclipse to occur?

The phase of the Moon must be new and the Moon must be passing through Earth’s orbital plane


What conditions must exist for a lunar eclipse to occur?

The phase of the Moon must be full and the Moon must be passing through Earth’s orbital plane


While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?

1 hour or longer


In general, what is true of the alpha star in a constellation?

It is the brightest star in the constellation


Where on Earth can you observe all the stars in the sky over an entire year?

Equator


Spring Equinox:

The Sun rises due east today, but will rise slightly north of due east tomorrow


Summer Solstice:

-Longest day of the year
-The noontime Sun reaches its highest point of the year


Fall Equinox:

The Sun has declination 0 degree today, but will have a negative declination tomorrow


Winter Solstice:

-The noontime Sun casts the longest shadows
-sunset occurs at its farthest point south of due west for the year
-the Sun crosses the meridian 23.5 degrees lower in the altitude than the celestial equator


How long is the precession cycle?

26,000 years


The place the Sun stops its northward motion along the ecliptic is the:

Summer Solstice


The places where the Sun crosses the equator are called the:

Equinoxes


Polaris will not always be the pole star due to:

Precession shifting the celestial pole


What conditions are necessary for a total solar eclipse?

New moon on ecliptic near perigee


Constellations appear to move across the sky at night because:

The Earth spins on its axis


The path that the Sun, Moon, and planets follow through the constellations:

Ecliptic


How long does it take the Sun to complete one circuit of the ecliptic?

1 year


What causes Earth’s seasons?

Earth’s rotational axis is tilted 23.5 degrees


Vernal equinox marks the beginning of:

Spring


Precession is caused by:

the gravitational pull of the Moon and Sun


How long does it take the Moon to go around the ecliptic?

1 month


Considering the Moon’s phases, everyone on earth sees:

The same phase in 24 hours


A solar eclipse happens:

About every 6 months at new moon


The angle of “Parallax” increases as:

The baseline gets larger


The angular diameter of an object:

Decreases if the object is farther away


Stars in a constellation are:

In the same part of the sky


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