Today is the spring equinox — one of the two days during the year when night is almost exactly equal to day — and in good ol’ fashioned APOD style, the folks at NASA are helping us understand and visualize this phenomenon by zooming out… waaaaay out.
The time-lapse above shows one year in thirteen seconds. Captured by the Meteosat, the geosynchronous satellite snapped an infrared image every day around 6am from September 2010 through September 2011, showing what the equinoxes and solstices look like from space and giving us a visual representation that explains why we have the seasons we do.
At the equinoxes, Earth’s “terminator” — the line between night and day, not a character played by Arnold Schwarzenegger — is perfectly vertical giving even light across both hemispheres. At the solstices, it is as diagonally oriented as it ever gets, providing more light and warmth to either the norther or southern hemisphere depending on the month.
So check out the video at the top to see what our blue marble looks like from space today, and if you want to learn more about this or download high res images of the equinoxes or solstices, check out NASA’s original post on the subject here.
Image credits: Photographs courtesy of NASA