A brief flash of green light was recently spotted coming from Venus in the night sky. The colorful shimmer has only been seen a handful of times before.
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A bright green flash, as well as more subtle shimmers of
other colors, was spotted coming from Venus in the night sky above Stockholm on
Jan. 8. (Image credit: Peter Rosén) |
Venus briefly flashed a shimmering green light in the night
sky above Sweden, new footage reveals. The rarely seen phenomenon is almost
identical to the ethereal green flashes that are occasionally seen around the
sun during sunrises and sunsets.
Photographer Peter Rosén captured the colorful flash coming
from one of our closest planetary neighbors while he was watching Venus rise
above the horizon in Stockholm in the early hours of Jan. 8, Spaceweather reported.
The bright flash, which lasted for around a second, was an
"unexpected bonus" that added to what was already an awe-inspiring
experience, Rosén told.
Similar green flashes are occasionally seen coming from the
sun as the sun rises above an ocean horizon. The light shows are caused by
light from the celestial objects being refracted, or split apart, as it passes
through our planet's atmosphere.
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Green flashes are most commonly seen during sunsets above
the ocean. |
Visible light is made up of different wavelengths of colored
light, which collectively give the rays a white color. But when light from the
sun shines through Earth's atmosphere, the individual wavelengths get partially
refracted by gas molecules. This happens all the time: For example, the daytime
sky appears blue because blue wavelengths scatter more than any other
wavelength.
However, with the right conditions, such as clear skies,
light from the sun and nearby planets can fully separate, especially when they
are positioned near the horizon because the light has to travel through more of
the atmosphere to reach the observer.
When this happens, shorter wavelengths of light, such as
blues and violets, are scattered the most, while longer wavelengths, like reds,
oranges and yellows, are more readily absorbed by molecules in the atmosphere.
As a result, mid-length green wavelengths are sometimes the only colors that
reach an observer. However, the angle has to be just right for this to happen,
which is why it only appears to the observer as a brief flash.
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Venus (circled) showed off its technicolor flashes shortly
after rising above the horizon above Stockholm. (Image credit: Peter Rosén) |
In the recent footage of Venus, green is the most prominent
color that flashes from the planet. But if you look closely you can also see
yellow, orange, red and blue light shimmer around as well.
In some circumstances, ice crystals can also refract
sunlight in the atmosphere to create rainbow-colored clouds and halos of light
around the sun or moon. The same effect can also create rainbow rings around
objects as light is refracted by large grains of floating pollen.
Green flashes have been spotted coming from Venus a handful
of times before. Similar green flashes have also been captured in images of
Mercury and the moon.
But unlike green flashes around the sun, which appear more
frequently in the clear air above the ocean, these light shows are more
commonly seen through extremely cold air, which magnifies the effect. This
means planetary flashes are not so tightly constrained to the horizon,
according to Spaceweather.