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Posts by EarthSky

Image Credit: Arenamontanus
Science Wire | Jul 21, 2014

What exactly is twilight?

Twilight is the time of day between daylight and darkness. Astronomers, the experts on nighttime, recognize three kinds of twilight.

universe-bubble-cp
Science Wire | Jul 18, 2014

Is our universe a bubble?

The multiverse hypothesis – the idea that there are other universes – can be tested, scientists say.

Binoculars are the perfect stargazing tool
Tonight | Jul 17, 2014

Top 6 tips for using ordinary binoculars for stargazing

If you’re a beginning stargazer or a veteran of thousands of starlit nights, binoculars can be your best friend. Here’s how to get started.

Photo credit: Mike Quinn
Science Wire | Jul 17, 2014

How can I see a green flash?

It’s said that once you’ve seen a green flash, you’ll never go wrong in matters of the heart. Here’s all you need to know … plus great pics.

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Tonight | Jul 13, 2014

Crepuscular rays, or sunrays

Conditions must be just right to see beautiful, mysterious sunrays – also called crepuscular rays. They often appear after sunset or before sunrise.

Telstar, via NASA
This Date in Science | Jul 10, 2014

This date in science: First Telstar launch

Telstar was the first satellite able to relay television signals between Europe and North America. It launched on this date … and helped change the world.

Matt Robinson in Sunderland, U.K., saw this wonderful, electric-blue noctilucent clouds on July 7, 2014.  They are sometimes called night-shining clouds.
Today's Image | Jul 10, 2014

Electric blue night-shining clouds

2014 has been a great year for noctilucent, or night-shining, clouds, seen at high latitudes only from about mid-May to August. Wondrous, if you can catch them!

fruit-fly-lab-ISS
Science Wire | Jul 09, 2014

Why are fruit flies boarding the International Space Station?

They’re about to become genetic models for astronauts, to help explore the long-term effects of space flight and deep space travel.

Ceres and Vesta tracking together on Earth's sky dome in June and July 2014.  Photo and labels by Fred Espenak.
Today's Image | Jul 09, 2014

A rare alignment of Ceres and Vesta

This week, Fred Espenak posted this wonderful photo, which shows the minor planets Ceres and Vesta, together on Earth’s sky dome in late June and early July 2014.

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Videos | Jul 08, 2014

Awesome timelapse video of a microburst

This short timelapse video of a microburst in the desert, with images every 30 seconds, makes you feel nature’s power.