|images: NASA, ©SBF 2013|
Spring is almost here! Read about the science of this year's spring equinox, and then try some of the activity links below!
This Friday, March 20th is the vernal, or Spring Equinox, denoting the official start of spring. There are 2 equinoxes each year. These occur when the Sun crosses the celestial equator, and night and day are equal lengths, hence equinox. We experience seasons because of the Earth's tilt on its axis. The tilt generally results in there being either more daylight hours in a 24 hour period, or more dark hours in a 24 hour period depending on whether the hemisphere you live in is tilted toward the sun, or away from it. Two days of the year the Earth moves in more of an upright position, parallel to the direction of motion around the sun, allowing for the same number of hours facing the sun as facing away from the sun. These days are the spring and fall equinoxes.
This year, not only will we gladly welcome the spring season, some parts of the world will experience a total eclipse of the sun, and a super moon! A solar eclipse occurs when the moon passes between the sun and the Earth, blocking sunlight from a portion of the planet. In order to view this eclipse in its entirety, you would have to travel to the Northern Atlantic ocean, near Greenland and Iceland. However, parts of Europe, the Middle East, northwestern Asia and northern Africa will be able to view a partial eclipse.
A super moon occurs when the moon is new or full and it is at perigee, meaning it is at the point in its orbit where it is closest to Earth. Although we won't see the effects of the super moon, it will cause large tides. We experience 6 super moons in 2015, the new moons in January-March, and the full moons August- October.
The spring equinox brings many opportunities for learning, from the changes that we experience as the season shifts from winter to spring (or summer to fall for the Southern hemisphere), Earth and the moon's motion, solar eclipses, and hemisphere geography. There are many fun activity ideas for teaching and learning about these concepts in the resource links below.
- Earth Sky: "Everything you need to know: vernal or spring equinox 2015"
- Earth Sky: "Supermoon total eclipse of equinox sun on March 20"
- Earth Sky: "When is the next Supermoon"
- The Four Seasons: Activity to understand the Earth's tilt causes the seasons
- Where is the Sun? Model the changing position of the sun with simple materials
- Dress for the Weather- Preschool level digital interactive for learning 4 seasons
- What Season is it? Preschool digital interactive
- NASA: Solar Eclipse Flipbook
- Why do Eclipses Happen? Model an eclipse with simple materials
- NASA: How can the little Moon hide the giant Sun?
- Super Moon: Interview with a NASA scientist, video and great diagrams