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What’s the birthstone for May?

Happy birthday May babies! Your birthstone, the emerald, is a type of beryl colored green by chromium. Perfect emeralds are among the rarest of gemstones.

Why do we celebrate May Day?

Happy May Day! A few words about this annual celebration, which has its roots in astronomy.

Why birds smash into windows

Up to 1 billion birds die each year in the U.S. due to collisions with windows. Why do birds slam into windows, and what can you do to prevent it?

New Project Skyglow video and giveaway

The guys at Project Skyglow have done some amazing videos, and they have a new book out. It’s not too late to enter their giveaway, honoring International Dark Sky Week.

Why cats can’t resist (even a phony) box

Twitter has been blowing up with posts on cats’ attraction to taped squares on the ground. An animal behavior expert explains what draws Fluffy to the #CatSquare.

This asteroid and comet look similar

Radar images of close-passing large asteroid 2014 JO25, which swept near last week, show it looks a lot like Comet 67P/Churyumov–Gerasimenko, which was explored by the Rosetta spacecraft.

Celebrating science, the Earth and the sky

Earth Day and the March for Science, April 22. International Dark Sky Week, April 22-28. Links and resources for all 3, here.

Video: Cassini’s final crazy engineering

During Cassini’s close pass of Titan on April 21-22, Titan’s gravity will bend Cassini’s orbit around Saturn, shrinking it slightly, so that instead of passing just outside the rings, the spacecraft will begin its Grand Finale dives just inside the rings. Wow!

Asteroid 2014 JO25 bigger than expected

It’s coming closer today than any asteroid this large since 2004. It came into view of small telescopes a few hours ago. Early radar observations indicate it’s bigger than we thought.

Green moon on April 20, 2017? Nah

The green moon rumor started in 2016. Now it’s back. It’s a joke, y’all. We’re not going to have a green moon on April 20, 2017. This joke has its roots (ahem) in cannabis culture.