by APOD Robot » Tue Dec 05, 2017 5:05 am
A Horizon with Blue and Red
Explanation: What's happening on the horizon? The horizon itself, past a
spinach field in
Guatemala, shows not only trees but a large volcano: the
Volc�n de Fuego (Volcano of Fire). The red glow at the top of the volcano is hot lava. But your
eye may also be drawn to the blue circle above the horizon on the left. This circle surrounds the
Moon and, together with other colors, is called
a corona. A
corona is caused by
diffraction of light -- here moonlight -- by small water droplets in the
Earth's intervening atmosphere. A break in the clouds on the right shows stars and even the
planet Saturn far beyond the volcano. Although
Volc�n de Fuego frequently undergoes low-level activity, the astrophotographer considered himself lucky to capture the scene just during an
explosive eruption in late September.
[/b]
[url=https://apod.nasa.gov/apod/ap171205.html][img]https://apod.nasa.gov/apod/calendar/S_171205.jpg[/img] [size=150]A Horizon with Blue and Red[/size][/url]
[b] Explanation: [/b] What's happening on the horizon? The horizon itself, past a [url=https://en.wikipedia.org/wiki/Spinach]spinach[/url] field in [url=https://en.wikipedia.org/wiki/Guatemala]Guatemala[/url], shows not only trees but a large volcano: the [url=https://en.wikipedia.org/wiki/Volc%C3%A1n_de_Fuego]Volc�n de Fuego[/url] (Volcano of Fire). The red glow at the top of the volcano is hot lava. But your [url=http://www.commentsyard.com/wp-content/uploads/2015/06/All-Cats-Looking-Up-540x338.jpg]eye may also be drawn[/url] to the blue circle above the horizon on the left. This circle surrounds the [url=https://solarsystem.nasa.gov/planets/moon]Moon[/url] and, together with other colors, is called [url=https://apod.nasa.gov/apod/ap150615.html]a corona[/url]. A [url=https://apod.nasa.gov/apod/ap160111.html]corona[/url] is caused by [url=http://www.atoptics.co.uk/droplets/corform.htm]diffraction[/url] of light -- here moonlight -- by small water droplets in the [url=https://www.nasa.gov/sites/default/files/images/463940main_atmosphere-layers2_full.jpg]Earth's intervening atmosphere[/url]. A break in the clouds on the right shows stars and even the [url=https://apod.nasa.gov/apod/ap170829.html]planet Saturn[/url] far beyond the volcano. Although [url=https://www.youtube.com/watch?v=QiYM4P-I4io]Volc�n de Fuego[/url] frequently undergoes low-level activity, the astrophotographer considered himself lucky to capture the scene just during an [url=https://apod.nasa.gov/apod/ap150311.html]explosive eruption[/url] in late September.
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