Eclipses

1
Eclipses

• Solar eclipse (new) moon blocks sunlight
  Earth is in moons shadow
• Order sun, moon, earth
• Lunar eclipse Earth blocks sunlight from
  hitting (full) moon moon is in Earths shadow
• Order sun, earth, moon

2
Shadows

• Umbra darkest part of shadow this shadow causes
  total eclipses
• Penumbra Outer, less dark shadow

Lunar Eclipse
Anyone here would see a total eclipse
Moon
There are also partial eclipses Partial Lunar
when part of moon is in umbra (there are also
penumbral eclipses) Partial Solar seen by anyone
in the penumbra
Solar Eclipse
http//www.astronomy.ohio-state.edu
3
Eclipses

• Generally 2 solar and 2 lunar eclipses a year
  not always total.
• Area on Earth to see total solar eclipse is very,
  very small - why seeing one is so rare (rest of
  Earth able to see anything sees a partial
  eclipse)

http//oiswww.eumetsat.org
4
Solar Eclipse
http//www.astro.uva.nl
5
List of Eclipses
6
Total Solar Eclipse you see the Suns Corona
Say ooooooh!
http//www.astropix.com
7
Pictures of Annular Eclipses
http//www.astronomy.com
Occurs when the moon is at a point where it is
not big enough to block all of the sunlight a
ring of sunlight is visible
http//media.skytonight.com
8
Lunar Eclipse

• Can be seen anywhere on Earth that the moon is
  visible
• 843 PM - Partial Eclipse Begins
• 1001 PM - Total Eclipse Begins
• 1026 PM - Mid-Eclipse
• 1051 PM - Total Eclipse Ends
• 1209 PM - Partial Eclipse Ends

http//www.jsu.edu
9
Lunar Eclipse

• Eclipsed moon looks red because some sunlight
  bends as it passes through Earths atmosphere
  before hitting the moon

10
Tides

• Tides occur because the moons gravity does not
  pull with the same force on all parts of the
  Earth

http//serc.carleton.edu
11
High Tides
D
C
A
B

• Location A Moons 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

12
High Tides
D
C
A
B

• Location C The moons 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

13
Low Tides
D
C
A
B

• Locations B and D Water flows away from these
  locations towards points A and C low tide

14
Tides
High Tide
Low Tide
http//www.huntsmanmarine.ca
Every location on Earth has 2 high tides and 2
low tides every 25 hours
15
Spring and Neap

• The Suns gravity also pulls on Earths waters
• Sometimes the suns and moons gravity work
  together (spring tide) and sometimes they pull on
  the water in different (perpendicular) directions
  (neap tide)
• Spring and Neap tides happen twice a month

16
Spring Tide
http//www.huntsmanmarine.ca

• during full and new moons
• highest high tides and lowest low tides

17
Neap Tide

• Neap tide during first and last quarter moons
• lowest high tides and highest low tides

http//www.huntsmanmarine.ca