Wednesday, February 14, 2018

Across The Universe - Venus and the Triply Ultraviolet Sun

Venus and the Triply Ultraviolet Sun:

Discover the cosmos!
Each day a different image or photograph of our fascinating universe is
featured, along with a brief explanation written by a professional astronomer.


2018 February 4




See Explanation.  Clicking on the picture will download  the highest resolution version available.


Venus and the Triply Ultraviolet Sun

Image Credit:
NASA/SDO
& the AIA, EVE, and HMI teams;
Digital Composition:
Peter L. Dove



Explanation:
An unusual type of solar eclipse occurred in 2012.

Usually it is the
Earth's Moon that
eclipses the Sun.

That year, most unusually, the planet
Venus took a turn.

Like a solar eclipse by the Moon, the phase of Venus became a continually thinner
crescent as Venus became increasingly
better aligned with the Sun.

Eventually the alignment became perfect and the
phase of Venus dropped to zero.

The dark spot of Venus crossed our parent star.

The situation could technically be labeled a Venusian
annular eclipse with an extraordinarily large
ring of fire.

Pictured here during the occultation, the Sun was imaged in three colors of ultraviolet light by the Earth-orbiting
Solar Dynamics Observatory,
with the dark region toward the right corresponding to a
coronal hole.

Hours later, as Venus continued in its orbit, a
slight crescent phase appeared again.

The next Venusian transit across the Sun will occur in
2117.





Tomorrow's picture: bubble versus cloud




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Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman
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