Credit & Copyright: Marcella Giulia Pace
Explanation:
Follow
a sunset on a clear day against a distant horizon and you might
glimpse green just as the Sun disappears from view.
The green flash
is caused by refraction of light rays traveling to the eye
over a long path through the atmosphere.
Shorter wavelengths refract more strongly than longer redder wavelengths
and the separation of colors lends a green hue to the last
visible vestige of the solar disk.
It's harder to see a
green flash from the Moon,
not to mention the diminutive disks
of Venus
and Mercury.
But a telescope or telephoto lens and camera can help
catch this tantalizing result of atmospheric refraction
when the celestial bodies are near the horizon.
From Sicily, the top panels were recorded
on March 18, 2019 for the Sun and May 8, 2020 for the Moon.
Also from the Mediterranean island,
the bottom panels were shot during the twilight apparition
of Venus and Mercury
near the western horizon on May 24.
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 |
Yanvar' Fevral' Mart Aprel' Mai Iyun' Iyul' Avgust Sentyabr' Oktyabr' Noyabr' Dekabr' |
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Publikacii s klyuchevymi slovami:
Solnce - Luna - Venera - Merkurii
Publikacii so slovami: Solnce - Luna - Venera - Merkurii | |
Sm. takzhe:
Vse publikacii na tu zhe temu >> |