Monday, April 9, 2018

Apr 9 - Why Rainbows are Curved

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Why rainbows are curved

A rainbow isn't a flat 2-dimensional image on the dome of sky. It's more like a mosaic, composed of many separate bits ... in 3 dimensions. Visit this post for many beautiful rainbow images.

Cosmic cold front older than solar system

Astronomers were surprised to discover an enormous “cold front” millions of light years in extent and older than the solar system.

How the moon reveals the sun's mass

How do astronomers determine masses for distant space objects? Here's one example - using the moon's orbit as a baseline to find the mass of our sun - from EarthSky's Bruce McClure.

Tonight … Star-hop to the Coma star cluster

Long ago, the Coma star cluster represented the Lion's tufted tail. Today, we know it as an open star cluster, whose stars were born together and are still loosely bound by gravity.

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Star-hop to the Coma star cluster

Zhean Peter Nacionales in the Philippines captured this view of the Coma star cluster. He wrote, “I learned at the EarthSky page to star-hop from Leo to the Coma star cluster, so I packed up my camera and tripod. It was worth it.” 

Little cloud making whoopee

To make whoopee can mean: to engage in uproarious merrymaking. Linda Holtby used the phrase while posting this shot to EarthSky Facebook. She said she caught the shot from 38,900 feet (11,860 meters) up.

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