Fun Facts
Earth Day
- -first celebrated April 22, 1970
- -“creator” of Earth Day was Wisconsin senator Gaylord Nelson
- -April 22 is always Earth Day
- -EPA was created from all of the excitement of Earth Day
- -20 million people participated in the first Earth Day
- -several environmental acts passed in Congress because of Earth Day
Solstice
- -comes from the Latin sol (the sun) and sistere (to stand still)
Summer Solstice
- -Longest day of the year
- -on June solstice, Northern Hemisphere soaks up the most sun of any day of the year
- -24 hours of sun North of the Arctic Circle
- -24 hours of darkness in Antarctica
- -Happens at the same time of day across the Earth (ex: 11am in each time zone)
- -occurs when the sun is over head at noon in the Tropic of Cancer at 23.5 degrees N
- -shortest sunrise and sunset of the year
- -at Stonehenge on the Summer Solstice, you can watch the sun rise over the stones; it is set almost perfectly for this occasion
Winter Solstice
- -shortest day of the year
- -darkest day of the year
- -occurs when the sun is over head at noon in the Tropic of Capricorn at 23.5 degrees S
- -New Grange in Ireland has a sight line that is directed to see the Winter Solstice sunrise
Seasons
- -caused by the 23.5 degree tilt of the Earth’s axis
- -aphelion- farthest point from the Sun that the Earth will reach- this year July 4th at 3am EDT; 94.5 million miles away from the Sun
- -perihelion- closest point to the Sun that the Earth will reach- this past January 2nd; 91.4 million miles
- -3.1 million miles between the two points; 3.3% difference which leads to a 7% difference in radiant heat
Equinox
- -vernal equinox: the point where sun crosses the celestial equator from South to North; about March 21
- -ver is Latin for spring
- -autumnal equinox: the point where the sun crosses the celestial equator from North to South; about September 23
- -autumnus is Latin for autumn
- -night and day are equal- 12 hours light, 12 hours dark
- -axis of the Earth points neither towards or away from the Sun
Eclipse
- -occur when the satellite of a planet is located within .5 degrees of the plane of the ecliptic, on a line that passes through the center of the sun and the Earth
- -in one calendar year, there are a maximum 5 solar eclipses and 3 lunar eclipses
- -often occur in 3s- lunar, solar, lunar
- -eclipse shadow moves at 2,000 miles per hour at the poles and 1,000 miles per hour at the equator
Solar Eclipse
- -2-5 solar eclipses a year
- -at any given point on the Earth, there is 1 eclipse every 360 years
- -Saros Cycle: 18 year, 10 day for the entire orbit of the moon to precess once around its orbit plane so that the lunar nodes make one revolution
- -takes 3 Saros Cycles for a solar eclipse to repeat in a nearby spot- 54 years and 33 days
- -eclipses in Saros Cycle occur about a third of the way around the Earth from each other
- -occur only during the new moon
- -maximum time for Solar Eclipse is 7 minutes and 40 seconds
- -maximum time for annular solar eclipse is 12 minutes and 24 seconds
- -visible in a narrow path- maximum of 167 miles wide
- -occurs 2 weeks before or after a Lunar Eclipse
Lunar Eclipse
- -occurs only during a full moon
- -maximum time for a lunar eclipse is 3 hours and 40 minutes
- -maximum time the moon can stay in totality is 1 hour and 40 minutes
- -occur up to 3 times a year
- -visible over the entire hemisphere
Moon
- -reflects light
- -takes 29.5 days to orbit the Earth
- -in the Southern Hemisphere, the moon phases are similar, but the moon appears opposite from how it appears in the Northern Hemisphere
- -crescent that is waxing has a curve like a “C” in the SH; waning in the NH
Moon Phases
- -if the moon is smaller than a quarter, then the moon is in a crescent phase
- -if the moon is larger than a quarter, then the moon is in a gibbous phase
- -when the moon is getting bigger, the moon is waxing
- -when the moon is getting smaller, the moon is waning
- -when the crescent has a curve like a “D”, the moon is waxing
- -when the crescent has a curve like a “C”, the moon is waning
- -new moon is the first phase
- -waxing crescent is the next phase
- -then first quarter
- -waxing gibbous
- -full moon
- -waning gibbous
- -last quarter
- -waning crescent
- -then the cycle starts over at new moon
Daylight Saving Time (DST)
- -even though most people say Daylight Savings Time, it is actually Daylight Saving Time
- -starts at 2 am on the 2nd Sunday in March
- -ends at 2 am on the 1st Sunday in November
- -Not observed in: Hawaii, most of Arizona (except the Navajo Indian Reservation), American Samoa, Guam, Puerto Rico, and the Virgin Islands
- -observed over most of the world
- -not observed near the equator or in tropical locations because the amount of daylight is about the same
- -in the Southern Hemisphere, DST is observed from October to March since their summer is opposite of the Northern Hemisphere
- -DST saves electricity
- -in 1784, Benjamin Franklin was the first to advocate for DST because he saw people wasting candles late and night and sleeping past dawn
- -in 1883, railroads started standard time zones so that they could print when the trains would come
- -Congress passed standard time zones for the country in 1918
- -this law also included DST, but it was repealed in 1919 and left to the states to decide
- -in 1966 Congress passed the Uniform Time Act, standardizing the beginning and the end of DST, still leaving the states the option to participate
- -Indiana, which was divided between 2 time zones, didn’t use DST until 2005, which is when they decided to adopt it
- -in 2007, Congress updated the time changes from April and October to March and November