Inferior Conjunction of Venus

June 2, 2020: Tomorrow, June 3rd, Venus will pass almost directly
between the Earth and the sun. This is having a strange effect on the
planet’s shape. “It is like a ring of fire,” says Didier Favre, who sends
this picture from Brétigny-sur-Orge, France:


When Favre took the picture on June 1st, the sun was only 2 degrees
from Venus–hence the blue sky. “It was not an easy picture to take,”
says Favre, “but what a beautiful view!”

Why does Venus look like a ring? Simple: The planet’s nightside is facing
Earth. Sunlight filtering through the edge of Venus’s carbon dioxide
atmosphere forms a luminous ring around the dark disk.

Astronomers call this an “inferior conjunction of Venus,” and it’s one of the
best in decades. At closest approach on June 3rd, Venus will be only 29
arcminutes (about half a degree) from the center of the solar disk. Only
twice since 1961 has Venus come closer–during the famous Venus Transits
of 2004 and 2012 [ref].


A SOHO coronagraph image of the ongoing conjunction. The horizontal
line running through Venus is caused by the planet’s bright light overloading
the pixels of SOHO’s digital camera.

Observing Venus at this time is dangerous. With the sun just a fraction of a

degree away, it is easy for stray sunlight to sneak into optical systems, damaging
sensitive electronics and hurting human eyes. Only skilled observers taking careful
precautions should attempt it.

In space, the Solar and Heliospheric Observatory (SOHO) will be monitoring
the conjunction. Coronagraphs onboard SOHO use opaque disks to block the
glare of the sun, revealing nearby stars and planets.  It’s a type of  artificial solar eclipse.

Even SOHO will have some trouble, though. On June 3rd, Venus will be so close
to the sun that it briefly dips behind the coronagraph’s opaque disks, hiding the
moment of closest approach. Ground-based observers will have to try to fill in the gap.

Browse the Realtime Venus Photo Gallery for the latest images.

Realtime Venus Photo Gallery
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