Astronomy - Observations 3 Flashcards
The position of the sun at noon (locally) is on the ______________.
celestial meridian
When the sun transits, the time locally is _________.
12 noon
When the sun is at lower transit, the time is _________.
12 midnight
The apparent yearly path of the sun relative to the stars is called the _______.
ecliptic
Through what constellations does the sun pass during a year?
Zodiac
The direction of the sun’s annual motion during the year relative to the stars is _____________, 1° per day.
west to east
Every hour, the sun seems to move _____ per hour to the _____.
15° per hour to the west
The present first sign of the zodiac is ________.
Pisces
_______ discovered that the rate of precession is about ______ per year westward.
Hipparchus; 52 inches per year westward
The period of precession is __________.
25,780 years
The present “age” as determined by the first sign of the zodiac is _________.
Pisces
The next “age” will be _________.
Aquarius
Each age lasts about ___________.
2,000 years
The position of the north celestial pole changes due to
precession
The moon’s monthly motion is about ___ degrees east per day.
13.1° east per day
The moon will rise on the average ______ minutes _______ each day.
48 minutes later each day
Sidereal period of the moon:
27.3 days
Synodic period of the moon:
29.5 days
The moon’s path can be as much as ___ degrees from the ecliptic
5° from the ecliptic
It is sunset and you notice that the moon is in transit. What phase must the moon be?
first quarter
It is sunrise and you notice that the moon is setting. What phase must the moon be?
full moon
You see a waxing gibbous moon rising. What is the approximate time of the day?
3:00 pm
A solar eclipse can occur at __________.
new moon
A lunar eclipse can occur at __________.
full moon
A “ring of fire around the moon” eclipse is better known to astronomers as an
annular eclipse
The moon is primarily responsible for the tides. What other object has an effect on the tides?
the Sun
The most severe tides (highest high tide and lowest low tide) are called _____________.
spring tides
_____ tides occur at first and last quarter moon.
neap tides
If the full moon transits at midnight, where will it be relative to the celestial meridian in an hour (1:00 am)?
15° to the west
The moon crosses the ecliptic at points called _______
nodes
The annual motion of the planets is close to what celestial circle?
ecliptic
Which planets were found by methodical searches?
Neptune & Pluto
The periodic westward motion of Mars is called ___________.
retrograde motion
A superior (outer) planet will retrograde once every __________.
synodic period
Venus has a maximum elongation of about ____ degrees.
46°
