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].
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.