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FAQs

What’s the birthstone for October?

Photo credit: Orbital Joe

Photo credit: Orbital Joe

Meet tourmaline. It’s one of two birthstones for October. The other October birthstone is opal. More info inside this post. And happy birthday October babies!

When can you see Earth’s shadow?

Global view of Earth at night is a composite assembled from data acquired by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite over nine days in April 2012 and thirteen days in October 2012.  Image via NASA.

Night is a shadow. Global view of Earth at night is a composite assembled from data acquired by the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite in 2012. Image via NASA.

Earth’s shadow extends about 1,400,000 kilometers (870,000 miles) into space, in the direction opposite the sun. There are several good times to think about and be aware of Earth’s shadow. Follow the links inside to learn more…

How to watch a total eclipse of the moon

Total lunar eclipse mosaic by eclipse master Fred Espenak.   Visit his page for the April 14-14 eclipse.

Total lunar eclipse mosaic by eclipse master Fred Espenak. Visit his new website EclipseWise.com

Are you planning on watching the September 27-28 eclipse? Here are some tips.

Why no eclipse every full and new moon?

Photo credit: pizzodisevo

A solar eclipse happens at the new moon – when the moon passes between the sun and Earth. A lunar eclipse happens when the Earth, sun and moon align in space, with Earth in the middle. Why aren’t there eclipses at every full and new moon?

Why a totally eclipsed moon looks red

The image at left is a photo montage. It combines the famous Blue Marble image taken by the Apollo 17 astronauts with an image of a solar eclipse. The composite somewhat simulates the reason a lunar eclipse looks red – because, during a lunar eclipse seen from Earth, a person on the moon would see a solar eclipse, with sunlight streaming around Earth through our atmosphere. At right, a fully eclipsed moon takes on the reddish color of sunlight filtered and refracted through Earth’s atmosphere. Image at right via Jim Fakatselis. Composite image via AstroBob.

During a lunar eclipse, you’ll see the Earth’s shadow creeping across the moon’s face. The shadow will appear dark, like a bite taken out of the moon’s face, until the shadow completely covers the moon. Then, during the breathtaking moments of totality, the shadow on the moon’s face often often suddenly changes. Instead of dark, it appears red. Why?

What is a Blood Moon?

This is what a total eclipse looks like.  This is the total eclipse of October 27, 2004 via Fred Espenak of NASA, otherwise known as Mr. Eclipse.  Visit Fred's page here.

This is what a total eclipse looks like. This is the total eclipse of October 27, 2004 via Fred Espenak of NASA. We astronomy writers often describe a totally eclipsed moon as appearing ‘blood red.’ But Christians have a different definition for Blood Moon.

The fourth and final lunar eclipse in an ongoing tetrad – four lunar eclipses in a row – happens on September 27-28, 2015. Some will call it a Blood Moon.

Why Earth has 4 seasons

Image credit: James Jordan

Image credit: James Jordan

Many believe Earth’s changing distance from the sun causes the change in the seasons. But that is not the case.

What is a fairy ring?

Walter Jenks Morgan (British, 1847-1924),

Walter Jenks Morgan (British, 1847-1924), “A Fairy Ring”

Have you ever noticed mushrooms growing in a big circle? It’s known as a ‘fairy ring.’ Ok, you probably didn’t see it looking exactly like this. Click in for some photos of the way a fairy ring is more likely to look, plus an explanation of why these mushroom circles happen.

Earth has 3 trillion trees, says study

That’s more than previous estimates. But the number of trees has dropped by 46% since the start of human civilization, says the study.

Are solar eclipses more common than lunar eclipses?

Image by Joshua Valcarcel via Wikimedia Commons

Image by Joshua Valcarcel via Wikimedia Commons

It’s sometimes said that, on a worldwide scale, solar eclipses outnumber lunar eclipses by about a three to two margin. True?