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All you need to know: September equinox

2017’s September equinox arrives today. Happy autumn (or spring)!

Sun on the sky’s equator

Another great explanation of Friday’s equinox – plus beautiful graphics – from astronomer Guy Ottewell.

Earth will give this spacecraft a gravity boost today

OSIRIS-REx – bound for a 2018 encounter with asteroid Bennu – will sweep in close to Earth on Friday. It’ll be closest today just before 16:52 UTC (12:52 p.m. EDT).

See it! Young moon and Jupiter

Wow! The young moon returned, near bright Jupiter, on the last day of northern summer (southern winter). Photos from the EarthSky community, here.

More From Latest

Mercury’s poles icier than thought

The scorching hot surface of Mercury – our sun’s innermost planet – seems an unlikely place to find ice. But a new study suggests otherwise.

More evidence of water on Mars

Planetary researchers say a large sedimentary basin, named Aeolis Dorsa, contains some of the planet’s most spectacular and densely packed river deposits.

A Chinese perspective on autumn

Autumn is connected in Chinese thought with the direction west, considered to be the direction of dreams and visions.

Zap! Biologist measures electric eel’s shock on his own arm

Talk about dedication to science! This biologist stuck his arm into an eel tank – 10 times – to get an accurate measure of an eel’s shock. He said it felt “like touching a horse fence.”

Aging star blows off smoky bubble

A strikingly beautiful view of a delicate bubble of expelled material around the exotic red star U Antliae helps astronomers understand how stars evolve during the later stages of their life-cycles.

Wildlife Photographer of the Year 2017

Which one would you choose?

See it! Dance of planets before dawn

Mars emerged before dawn last week, to meet Mercury below bright Venus. And then the moon passed through. Thanks to all who submitted photos!

Dust devils on Earth and Mars

Researchers spent 5 years studying dust devils in earthly deserts. They said their research has implications for climate and weather on both Earth and Mars and for human health.

How to see binocular comet C/2017 O1

Long-period comet C/2017 O1 – a visitor from the Oort Comet Cloud – is becoming visible in small telescopes and binoculars. This post includes charts that can help you find it.