![]() ![]() In addition to two annual equinoxes, there are two solstices every year. The Difference between an Equinox and a Solstice Since the Earth actually takes about 365.24 days to orbit the sun, equinoxes happen around six hours later from year to year, before moving back a day on leap years. Six months after the March equinox, another equinox occurs around September 22 or 23 and marks the beginning of fall in the Northern Hemisphere and spring in the Southern Hemisphere. Additionally, equinoxes are the only two times a year that the sun rises due east and sets due west. Someone standing on the equator on an equinox can observe the sun passing directly overhead. As the Earth orbits the sun over the course of a year, different places get sunlight for different amounts of time.Īn equinox occurs at the moment when the Earth’s axis doesn’t tilt toward or away from the sun. The Earth tilts at an angle of 23.5 degrees on its axis relative to its plane of orbit around the sun. Weâve been living on it for a long, long time, but sometimes you need to get up and above it to truly appreciate its beauty.The vernal equinox occurs on March 20 or March 21 each year and signals the start of spring in the Northern Hemisphere (and fall in the Southern Hemisphere). Maybe this is just a billion years of evolution speaking, but I think our planet is a fantastic place, pleasing to the eye and to the brain as well. I think if I lived in space, once I stopped throwing up everything Iâve ever eaten since I was born, I could simply gaze out the porthole at our spinning globe. You can see the huge (and deadly) typhoon Usagi about to slam into China (in the still frame above, taken two days later, you can see itâs moved west), and the enormous swath of clouds splayed across the southern Indian Ocean (note again in the still frame the eastern tip has developed into a curled shape by the Coriolis effect). In the images used, the infrared images are colored red, which gives our planet an odd, Mars-like hue. You can see clouds swirling, the shadow line between day and night sweep across the globe, and even the reflection of the Sun in the waters beneath. Remember, from the point of view of the satellite, the Earth sits motionless underneath it ⦠but our atmosphere is anything but. 21 at 15:30 UTC) into this very cool animation: He also put together a dayâs worth of images from Elektro-L (ranging from Sep. The image was processed by journalist and space enthusiast Vitaliy Egorov. For the south pole, the Sun gets higher, meaning summer is coming. Of course, for the former the Sun gets lower every day, marking the oncoming winter. More importantly, note the illumination: The entire northern and southern hemispheres are lit! If you were on the north pole or the south pole, youâd see the Sun sitting right on the horizon. The IR is given a green tint in the picture to make it look more natural to our landlubber eyes. Itâs lovely, isnât it? The picture is a combination of visible light (the kind we see) and near infrared, which highlights vegetation. The picture shows the Earth on the day of the equinox, taken at about 05:30 UTC (01:30 EDT), 15 hours before the actual moment of the equinox. To the satellite, it appears to see the same face of the Earth all the time to us on the ground, the satellite appears frozen in the sky, occupying one spot in space. The time it takes to circle the Earth once is 24 hours, the same amount of time it takes the Earth to spin once. This orbits our planet high above the equator, in whatâs called a geosynchronous orbit. The picture above is from the Russian weather satellite Electro-L. ![]() The more you know.īut the equinox makes itself known if you look at the Earth from space. So daytime on the equinox is actually a few minutes longer than night. In reality thatâs a misnomer the Earthâs atmosphere acts like a lens, making the Sun rise a few minutes earlier than it would if the Earth were airless, and set a few minutes later as well. The word equinox itself means equal night, referring to the idea that daytime and nighttime are the same length on that day. This happens twice a year, the other time being at the vernal (spring) equinox in March. Not very enlightening, is it? Well, unless youâre an astronomer.Īnother way to say it is that the Sun was directly over the Earthâs equator, illuminating equally the Northern and Southern hemispheres. There are a number of ways to explain this, though the definition is that itâs the moment the center of the Sunâs disk has a declination of zero degrees when itâs moving southward in its annual path across the sky. EDT), to be exactâwas the moment of the autumnal equinox. A few days agoâ Sunday at 20:44 UTC (4:44 p.m.
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