September equinox: All you need to know

[elleng]

The equinox will arrive on September 22 at 13:31 UTC. That's when the sun will be exactly above Earth's equator, moving from north to south. Translate UTC to your time and read more: https://bit.ly/2O9UdsB 👓
Photo: Across a wide swath of the U.S. now, the sky looks hazy, and the sun looks redder than usual, due to the wildfires in the U.S. West. Nancy Ricigliano on Long Island, New York, caught this image on September 16, 2020, and wrote: “This is a result from the smoke from the wildfires that have reached so many places, including New York. This photo was taken at Jones Beach, Pier 10. Normally at this time, you can’t even take a picture of the sun without a filter.”

https://earthsky.org/astronomy-essentials/everything-you-need-to-know-september-equinox?

[Botany]

1. This is the fall we have been waiting for 4 years

It is time for Trump to go.

[mahatmakanejeeves]

2. Ever wondered why trees ditch their leaves each fall?

KidsPost

Ever wondered why trees ditch their leaves each fall?

What looks like pretty scenery to us is a matter of deadly serious survival for trees.

By Jason Bittel
September 20, 2020 at 8:00 a.m. EDT

Autumn arrives this week, and that means pumpkins, football and piles of fresh, crackly leaves. Did you ever wonder why trees throw away an important part of their anatomy each year? After all, wouldn’t it be similar to people losing all their hair — or even weirder, their skin — just as our part of the world gets colder? ... While it might seem strange from the point of view of a human, to a plant, losing leaves makes perfect sense.

Trees are solar-powered. Each leaf is loaded with a pigment called chlorophyll (pronounced CLORE-o-fill), which absorbs light and helps convert water and carbon dioxide into energy. The process is called photosynthesis (fo-toe-SYN-thuh-sis).

But there’s a problem. In parts of the world that experience seasons, winter means less and less sunlight each day. It also comes with biting cold that can freeze the liquids inside leaves. These two factors hamper the tree’s ability to make energy.

A full-grown oak tree might have more than 60,000 leaves, and each one requires valuable nutrients. So when fall turns into winter, trees discharge their leaves as a cost-cutting measure. If it had to spend resources on all those leaves through the winter, not only would the leaves freeze, but the tree would die.

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