Solar Week - Ask a Question



Come here during Solar Week (next one: March 22-26, 2021) to interact. To post a question, click on your area of interest from the topics below, and then click on the "Ask New Question" button. Or EMAIL or tweet or plant in Answer Garden your question about the Sun or life as a scientist to us -- and watch for it to appear here.  You can also visit our FAQs (frequently asked questions). In between Solar Weeks in October and March, you can view all the archives here.

PrevPrev Go to previous topic
NextNext Go to next topic
Last Post 3/29/2017 11:59 AM by  Kris Sigsbee
equinox around the world
 2 Replies
Sort:
You are not authorized to post a reply.
Author Messages

Gustavus





Posts:


--
3/29/2017 6:32 AM
    On the equinoxes, is there 12 hours of day and 12 hours of night all around the world?
    thank you
    Gus
    Tags: Equinox, world

    Kris Sigsbee



    Basic Member


    Posts:415
    Basic Member


    --
    3/29/2017 11:56 AM
    The spring (vernal) and fall (autumnal) equinoxes are the only two times of the year when the Earth's axis is tilted neither toward nor away from the sun. At the geographic equator, the sun is directly overhead at noon on both of the equinoxes. Because the Earth's axis is not tilted towards or away from the Sun on the equinoxes, there are "nearly" equal amount of daylight and darkness at all latitudes. Sunrise is defined as the instant when the leading edge of the Sun's disk becomes visible on the horizon, whereas sunset is the instant when the trailing edge of the Sun's disk disappears below the horizon. The nearly equal hours of day and night are due to refraction (or bending) of sunlight that causes the edge of the Sun's disk to appear above the horizon when the actual position of the Sun is below the horizon. The Earth is round, so the days become a little longer at the higher latitudes because it takes the sun longer to rise and set. The length of daylight on the equinoxes will actually range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.

    Kris Sigsbee



    Basic Member


    Posts:415
    Basic Member


    --
    3/29/2017 11:59 AM
    You can read about the equinox at the North Pole here https://www.pmel.noaa.gov...lery_np_seasons.html
    You are not authorized to post a reply.


    Twitter Feed

    Scientist Leaderboard

    Name # of replies
    Multiverse skin is based on Greytness by Adammer