NOW FOR SOME IMPORTANT (AND INTERESTING)
INFORMATION TO MAKE SURE YOU HAVE IN YOUR
MOON BOOK NOTES
You only need to write what is in bold and underlined
Moon Info It takes the same amount of time for
the moon to rotate on its axis as it does to revolve around the Earth (27.3 days)
This is the reason why the Earth only sees one side of the moon – in order to see the other side you need to get on a space ship and go around the moon!
There are 29.5 days from a new moon to the next new moon
Moon Info The lit part of the
moon always points towards the sun.
When waxing: light is on the right
When waning: shadow is on the right
http://www.astro.virginia.edu
The moon rise, moon set The time of the moon rise and set depends on
its phase Rises in the East and sets in the West – due to
Earth’s rotation Remember: moon rises about 50 min later each
day of the moon phase cycle (~ 25 to 75 mins)
Phase Rise Time Midpoint in sky Set TimeNew Sunrise Noon Sunset
1st quarter Noon Sunset Midnight
Full Sunset Midnight Sunrise
3rd quarter Midnight Sunrise Noon
http://aa.usno.navy.mil/cgi-bin/aa_rstablew.pl
Can you identify the phase?
Waxing Gibbous
Full
Waning Crescent
Waning Gibbous
New
Last (3rd) Quarter
First Quarter
Waxing Crescent
Tides Tides are the rise
and fall of water – rise for about 6 hours then fall for about 6 hours
Tides occur because the moon’s gravity does not pull with the same force on all parts of the Earth
http://serc.carleton.edu
High Tides
Location A: Moon’s gravitational force on the water is greater than its force on the Earth as a whole
Water here is pulled more towards the moon than the Earth = high tide
A
D
B
C
High Tides
Location B: The moon’s gravitational force on the Earth as a whole is stronger than its force on the water
The Earth is pulled more towards the moon and the water is “left behind” = high tide
A
D
B
C
Low Tides
Locations C and D: Water flows away from these locations towards points A and B = low tide
B
D
C
A
Spring and Neap The Sun’s gravity also pulls on Earth’s
waters Sometimes the sun’s and moon’s gravity
work together (spring tide) Sometimes they pull on the water at right
angles (neap tide) Spring and Neap tides both happen twice
a month
Spring Tide
during full & new moons highest high tides & lowest low tides Greatest tidal range (difference between
high and low tide)
http://www.huntsmanmarine.ca
Neap Tide Neap tide: during
first & last quarter moons
lowest high tides & highest low tides
Smallest tidal range
http://www.huntsmanmarine.ca
Shadows
Umbra: darkest part of shadow: this shadow causes total eclipses
Penumbra: Outer, less dark shadow
Lunar Eclipse Moon in Earth’s shadow (Earth blocking
sunlight from hitting Moon) Earth cannot “see” the moon Order: Sun, Earth, Moon Do not have an eclipse every full moon
because moon’s orbit is at an angle
Moon
Lunar Eclipse
Total: Moon entirely in Earth’s umbra Partial: Moon partially in Earth’s
umbra Penumbral: Moon in Earth’s
penumbra
Moon
Lunar Eclipse Eclipsed moon
looks redish orange (rust) because some sunlight bends as it passes through Earth’s atmosphere before hitting the moon
Lunar Eclipse Last total lunar eclipse
was on February 20, 2008
Last partial – June 26, 2010 (we couldn’t see this in CT)
Next total eclipse on Dec 21, 2010
Generally 2 eclipses (total, partial or penumbral) a year
http://www.jsu.edu
Picture of the entire length of March 2007’s Eclipse
Stefan Seip (TWAN)
Solar Eclipse
Earth is in moon’s shadow (moon blocking sunlight from hitting Earth)
Earth cannot “see” the sun Order: Sun, Moon, Earth
Solar Eclipse
Total: Earth in Moon’s umbra Partial: Earth in Moon’s penumbra
Pictures of Annular Eclipses
Annular: moon is at a point where it is not big enough to block all of the sunlight: a ring of sunlight is visible
http://www.astronomy.com
Solar Eclipse Last total eclipse = Jul 11,
2010 – seen in Chile There are only partial
eclipses in 2011 Next total eclipse = Nov 13,
2012– seen in Australia Next eclipse visible in
Eastern USA – a partial eclipse in 2014
There can be 2 - 4 eclipses (total, partial or annular) a year (at most 5)
http://www.astro.uva.nl
Eclipses 2010
Solar and Lunar Eclipses of 2010
Annular Solar Eclipse of 2010 Jan 15
Partial Lunar Eclipse of 2010 Jun 26
Total Solar Eclipse of 2010 Jul 11
Total Lunar Eclipse of 2010 Dec 21
Eclipses 2011
Solar and Lunar Eclipses of 2011
Partial Solar Eclipse of 2011 Jan 04
Partial Solar Eclipse of 2011 Jun 01
Total Lunar Eclipse of 2011 Jun 15
Partial Solar Eclipse of 2011 Jul 01
Partial Solar Eclipse of 2011 Nov 25
Total Lunar Eclipse of 2011 Dec 10