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EarthSky

Sunlight through trees in Singapore

When sunlight filters through trees, you may get a corona effect where the rays from the light sources take on the colors of the rainbow.

Before they disappear, watch for Orion and Sirius

Orion the Hunter is one of the sky's most noticeable constellations. Sirius is the sky's brightest star. As Earth revolves around the sun, they're both about to disappear for awhile. Here's how to star hop from Orion's Belt to Sirius.

Use the Big Dipper to find the Little Dipper

Polaris - aka the North Star - marks the end of the Little Dipper’s handle. The 2 outer stars in the bowl of the Big Dipper always point to Polaris.

Is the Hyades star cluster being destroyed?

Data from ESA’s Gaia star-mapping satellite have revealed tantalizing evidence that the famous V-shaped Hyades - nearest star cluster to our sun - is being disrupted. The culprit may be a suspected population of dark matter sub-halos. Wow!

Follow the arc to Arcturus, drive a spike to Spica

If you only ever learn one star mnemonic, make it this one!

Striking new image of M106

This spectacular image features spiral galaxy Messier 106 and its diminutive neighbors, as well as a dense field of background galaxies and foreground stars.

57th anniversary of North America’s biggest earthquake

On Good Friday, March 27, 1964, south-central Alaska heaved under one of the most powerful earthquakes ever recorded, registering a 9.2 on the Richter scale.

Does a green sky predict a tornado?

Sometimes, before a tornado strikes, the sky turns an eerie green color. The answer to why the sky is blue will help you understand why the sky is sometimes green before bad weather.

Torrential rains drench Hawaii

A strong tropical depression picking up moisture from the warm ocean caused widespread flooding in the Hawaiian islands.

Beware the Ides of March? Why?

The Ides of March are March 15. We in modern times probably wouldn't know about them - or know we're supposed to beware of them - if it weren't for William Shakespeare.