This star undergoes a long-term dimming that's so mysterious it was, at one time, proposed as possible evidence of an alien culture. Now, scientists say, a disk of debris - torn from a melting exomoon - might explain Tabby's Star. Read more.
The equinox fell this morning at 07:50 UTC (3:50 a.m. Eastern Daylight Time). Translate UTC to your time. One equinox instant … different local times around the world. Happy fall or spring, y'all. Here's all you need to know.
Equinox means equal night. Days and nights are nearly equal at the equinox, but not quite. Here's why. Also, we've got a new word for you, equilux. It's the word for when day and night are, in fact, equal. Read more.
This illustration by Tau'olunga via Wikimedia Commons shows the day arc of the sun, every hour - during the equinoxes - as seen on the celestial dome from the equator. Also showing twilight suns down to -18° latitude. Note the sun at the zenith at noon and that the tree's shadow is cast straight down. That is - as seen from the equator on the day of an equinox - a tree stands in the center of its own shadow. Read more.
View at EarthSky Community Photos. | First sunrise of autumn - today's sunrise - from our friend Dr Ski in the Philippines. He wrote: "Of course, in the jungle, there is no autumn. We only have 2 seasons here: Monsoon Season and Not-Monsoon Season." Thanks, Dr Ski! Read more about the equinox.
