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FAQs

What’s the birthstone for January?

Photo credit: cobalt123

Photo credit: cobalt123

Happy birthday January babies! Your birthstone, the garnet, symbolizes a light heart, loyalty and enduring affections.

The name “garnet” is derived from the Latin “granatum” meaning “pomegranate” because the crystals resemble the red color and seed-like form of this fruit.

How many stars can you see on a clear, moonless night?

Stars over Mount Bethel in the Arapaho National Forest in Colorado.  View larger. via EarthSky friend Daniel McVey.  See more of Daniel's photos here.

Stars over Mount Bethel in the Arapaho National Forest in Colorado via EarthSky friend Daniel McVey.

The moon is waning now, and the evening sky is free of bright moonlight. By this weekend, the only moon you see will be a waning crescent in the hours before dawn. Good weekend to go camping and observe some dark skies! You might wonder … how many stars can you see with the eye alone?

What causes Death Valley’s sliding stones to move?

The video above shows a famous sliding stone of Death Valley’s Racetrack Playa in motion. See it? It’s the big rock in the foreground. Watching this video, you become one of the first people on Earth to see a sliding stone in motion. Although their tracks across Racetrack Playa – a dry lake bed in Death Valley – have been observed and studied since the early 1900s, no one had ever seen the stones in motion … until recently. What’s more, the researchers who captured this video say they now know what causes the stones to move.

Was the Christmas Star real?

What was the Christmas Star? Scientist Bradley Schaefer has some new things to say on this week’s EarthSky 22. Photo by Russell Croman

The Star of Bethlehem, or Christmas Star, is mentioned in the Bible. It’s said to have led the three wise men to Bethlehem. But was the Christmas Star a real object in the sky? Or was it just a symbol?

Why do most evergreen trees have a pyramid shape?

evergreen trees conifers

Photo credit: Bill Abbott/Flickr

Those who admire the shape of a Christmas tree might like to know that its shape has evolved in response to wind, snow, and light.

How high up are meteors when they begin to glow?

Geminid meteor. Photo by Tommy Eliassen. Capture time: 00:12am, Dec 11, 2014.  Location: Lovund, Nordland, Norway.

Geminid meteor. Photo by Tommy Eliassen. Capture time: 00:12am, Dec 11, 2014. Location: Lovund, Nordland, Norway.

Your Friday FAQ. Geminid meteor shower peaks this weekend!

I saw a flash in the night sky. What is it?

EarthSky Facebook friend Simon Waldram, in Spain, saw and photographed what looks like an iridium flare. Thank you, Simon.

Many people ask us about flashes in the night sky. They see one and want to know, what is it? Unless one of us were standing there next to you, we have no way of knowing exactly what you saw. So we can’t say for certain. But it’s possible that what you saw is a flare from an iridium communications satellite.

Why aren’t the earliest sunsets on the shortest day?

In early December, the Southern Hemisphere is approaching its summer solstice.  Sunset on that part of Earth will continue coming later until early July.  Photo of sunset with crepuscular rays by Phil Rettke Photography in Ipswich QLD Australia.  Visit Phil Rettke on Facebook.

In early December, the Southern Hemisphere is approaching its summer solstice. Sunset on that part of Earth will continue coming later until early July. Photo of sunset with crepuscular rays by Phil Rettke Photography in Ipswich QLD Australia.

The winter solstice is the shortest day. It offers the shortest period of daylight. But the earliest sunsets aren’t on the solstice itself. Instead, they come a couple of weeks before the winter solstice. If you’re at a temperate latitude of the Northern Hemisphere, your earliest sunsets are in early to mid-December.

Is it better to be a night owl or an early bird?

This Friday’s FAQ …Early birds versus night owls. Who wins the battle over bedtime? Let’s see what the guys at AsapSCIENCE have to say about this one. New video!

What’s the birthstone for December?

Turquoise

Turquoise

Happy birthday to all our December-baby friends! December has two birthstones, turquoise and zircon.