Astronomy Lunar and Solar Eclipses & Kepler's Laws
What is a solar eclipse?
- Moon covers sun -Occurs during new moon phase - people of sumer love solar eciplses
What is a lunar eclipse?
-Occurs close to full moon phase -We don't see the moon - Moon ppl "Begging for mercy" against the earth shadow
Conic Section
A conic section is the intersection of a plane and a cone.
Eccentricity
A parameter that shows how different an eclipse is from a perfect circle. - circle is an ellipse with zero eccentricity - greater eccentricity equals more elongated eclipse 0<E<1 -Extreme ellipse 9
Kepler's Second Law ( Law of Equal Areas)
A planet moves faster in the part of its orbit nearer the Sun and Slower when farther fro the Sun,sweeping out equal areas in equal times. -Speed at which a planet orbits is always changing
Why don't we see eclipses every month?
Because the Earth's orbit around the sun is not in the same plane as the Moon's orbit around the Earth. - If there is no tilt they all move on the same plane - Most of the time the moon is below the eccliptic
Why is the moon red during a lunar eclipse?
Due to 1.) refraction 2.) red light goes through atmosphere ( think of why is sky blue) - Light goes through the atmosphere small fraction of light goes to umbra. because of refraction some light illuminates the moon and only red light goes through the atmosphere
Kepler's Third Law ( Law of Harmonies) p2=a3
Kepler's law tells us that more distant planets orbit the Sun at slower average speeds. Mathematically, it states that planets obey the relationship p2=a3 - p = orbital period of 1 year -A= the average distance from Sun in astronomical units - the square the of p2 equals the a cubed
What is a total lunar eclipse?
Moon passes entirely through umbra - moon sun earth nearly perfectly aligned
What is the penumbral lunar eclipse?
Moon passes only through penumbra -
What is the partial solar eclipse?
Only part of the sun is blocked from view
What is a partial lunar eclipse?
Part of the moon passes through the umbra -Less perfect alignment
What is an Umbra?
Sun is completely blocked
What is the Penumbra?
Sun is partially blocked
Kepler's First Law ( The Law of Ellipses) Remember 1=1
The orbit of each planet about the sun is an eclipse with the Sun at one focus - Perihelion- closest distance to sun - Aphelion farthest way from sun
What's the difference between an angular and solar eclipse?
The sun is bigger
How are the Umbra and Penumbra related to partial and total eclipse? Ask this question
They are related because the moon earth and sun must be on the same line and the Sun moon earth must ne on the same line. ( lunar; solar)
What are the three types of lunar eclipses
Total lunar eclipse Partial lunar eclipse Penumbral lunar eclispe
What are the three types of solar eclipses?
Total solar eclipse Participial solar eclipse Annular eclipse
What is refraction?
When light changes direction of propagation moving from one medium to another
What is totality?
When the moon is completely engulfed in the umbra
Why is the moon red?
When the moon is entirely in complete shadow you see red.
What is the annular eclipse?
a ring of sunlight surrounding the moon - small region of Earth Size of moon changes when moon is closest to the earth perigee and further away from the sun apogee
What is the total solar eclipse?
total solar eclipse the moon is relatively close to Earth in it's orbit, the moon's umbra touches a small area of earth's surface
