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FAQs

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?

Why aren’t there eclipses at 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?

What’s the birthstone for April?

Photo credit: Kim Alianz

Photo credit: Kim Alianz

Happy birthday April babies! Your birthstone, the diamond, is the rich cousin of graphite.

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.

The April 4, 2015 total lunar eclipse comes in the morning for North America, and in the evening for Eastern Asia, Indonesia, New Zealand and Australia. Here’s what to look for.

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.

A lunar tetrad – four total lunar eclipses in a row – began a year ago. The next eclipse in this tetrad will take place on April 4, 2015.

Video: What is a pulsar?

A pulsar is a rapidly spinning neutron star which is the small, incredibly dense remnant of much more massive star. How dense? A teaspoon of matter from a neutron star weighs as much as Mount Everest.

What is a Dyson sphere?

View larger. | Here is a completely fantastic artist's concept of a Dyson sphere.  I like it.  Notice the little moon on the left side, being ravaged for raw materials.  Via FantasyWallpapers.com

View larger. | A fantastic artist’s concept of a Dyson sphere. The image is called Shield World Construction, and it’s by Adam Burn.

Proponents of solar power know that only a tiny fraction of the sun’s total energy strikes the Earth. What if we, as a civilization, could collect all of the sun’s energy? If so, we would use some form of Dyson sphere, sometimes referred to as a Dyson shell or megastructure.

Why does Earth have four seasons?

Photo credit: Jane Wildoner

Photo credit: Jane Wildoner

A Friday FAQ specially selected for equinox day.

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

When is the next supermoon?

What most call a Blue Moon isn't blue in color. It's only Blue in name. This great moon photo from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.

Moon photo is from Rebecca Lacey in Cambridge, Idaho.

According to the definition of supermoon coined by Richard Nolle 30 years ago, the year 2015 has a total of six supermoons. They are the new moons of January, February and March and the full moons of August, September and October. The September 28, 2015 full moon will be the closest supermoon of 2015. The next supermoon – on March 20, 2015 – will cause a total eclipse of the sun! Follow the links inside to learn about the supermoons of 2015.

Why beware the Ides of March?

Image credit: veraukoion

Image credit: veraukoion

If you have heard of the Ides of March, you know you’re supposed to beware them. Why? In ancient Rome, the ides of March were equivalent to our March 15th. You probably know of the Ides of March thanks to William Shakespeare. In his play Julius Caesar, a soothsayer – or fortune teller – says to Caesar: Beware the Ides of March.