Unit 1. Test Flashcards
What star has a declination of almost exactly 90 degrees as the “pole” star? Hint: It was the center of the star map
Polaris
On what calendar day would the SOUTH Pole have a day of “total darkness”?
June 21st
Why is the “peak” of summer in the northern hemisphere usually more than a month after summer solstice?
The water is just warming up and it takes awhile to do so
Explain why the moon appears to have “phases” that have nothing to do with shadows being cast by earth.
Because what we see is what is being REFLECTED off of the moon from the sun
About how long does it take light to reach us from the next nearest star, Proxima Centauri?
4 light years
What would cast a smaller umbra (total shadow), a solar eclipse or a lunar eclipse?
Solar eclipse
What is more common to be observed, a total lunar eclipse or a total solar eclipse? Why?
Lunar, more area can see it
The distances in our solar system: would you be better to measure them in astronomical units or light
years? Why?
Astronomically, easier numbers for our brain to comprehend
Name the eight moon phases in order starting with new moon.
- New moon
- Waxing Crescent
- 1st Quarter
- Waxing Gibbous
- Full Moon
- Waning Gibbous
- 3rd Quarter
- Waning Crescent
What conditions in our solar system have to be met in order for a total solar eclipse to happen?
Sun, moon, and earth need to be directly lined up
__________ measures north and south of the celestial equator in degrees.
Declination
What is the term for a 27.5-day month, the length of time for one revolution of the moon around the earth?
Sidereal
What percentage of the universe can we directly study by means of direct observation?
4%
- A ______________ day is determined by measuring the length of time from “sunrise” to “sunrise”.
Solar
If you measure the length of time it takes the sun to go all the way through the ecliptic, through all 13
constellations, you have measured one _______ year.
Sidereal
The measurement east and west on the celestial sphere is called ___________
Right Ascension
The 29 days it takes the moon to go through a complete set of phases is called a ____________
Synodic Month
The Latin meaning of the word “equinox” is…
Equal Night/Day
The Latin meaning of the word “solstice” is…
Sun Stand (still)
To spin completely around on one’s own axis is to ____________
Rotate
Astronomy is a branch of what larger science?
Physics
How long would it take light to reach the earth from the sun?
8 minutes
How many days (approximately) does each moon phase last?
3.5 days
What phase does the moon have to be in to have a total solar eclipse?
New Moon
What’s the difference between a light year and a calendar year?
Light year - distance
Calendar year - time
What moon phase would most likely rise at noon and set at midnight?
1st Quarter
What phase of the moon would be more ideal for observing through a telescope?
Waxing Gibbous
What is the name of the closest major galaxy?
Andromeda
What is the name of the path of the sun as it travels through the 13 constellations of the zodiac?
Ecliptic
What very amazing coincidence is known as the “400 rule”?
The sun is 400x bigger than the moon but the moon is 400x closer than the sun to earth
What calendar day would be the “longest” day for us in the northern hemisphere?
June 21st
What time of year is the earth technically closest to the sun for us in the northern hemisphere?
January 4-6
- A “tropical” year is the same thing as a _____ year, 365.25 days.
Solar
- The sidereal year is actually ________ longer in time than the solar year.
20 minutes
Why can’t we see real pictures of the Milky Way as a spiral?
Our solar system is located in the disc so we can only see where it crosses over and not the whole shape
What types of objects did Charles Messier catalogue in his famous Messier catalogue?
Diffuse nebulae, planetary nebulae, open clusters, globular clusters, and galaxies
What did Eratosthenes discover in Alexandria around 250 BC?
That the earth is a sphere
What date (roughly) would an astronomical calendar start with ideally (it isn’t January 1)?
March 21st
Describe what all you can observe during the moment of totality during a total solar eclipse.
360 degree sunset and bright stars and planets
The art of using the motion of stars and planets to attempt to predict human behavior is known as…
Astrology
When is the next major total solar eclipse in North America?
August 2045
Describe the path of totality and maximum length of totality for the next total solar eclipse in North America.
Will cross through Mexico, then through Texas up the east then pass through south Canada. 4 minutes 28 seconds
What is meant by the expression that the night sky is a “giant time machine”?
Since light takes so long to reach earth, any light we see has already happened from a couple minutes ago to billions of years ago
Roughly how many AUs from the sun is each planet, beginning with Mercury?
Mercury - 0.4
Venus - 0.7
Earth - 1
Mars - 1.5
Jupiter - 5.2
Saturn - 9.6
Uranus - 19.2
Neptune - 30
Pluto - 39.5
Describe an “annular eclipse”, and why they sometimes occur.
The “ring of fire,” size of moon cannot fully cover the sun
