Mercury tomorrow will be at the top of its best evening appearance of this year (for north-hemisphere skywatchers).
Its maximum of elongation from the Sun (just over 21 degrees) is actually reached on May 7 at 5 hours Universal Time, but in relation to our horizon it is a shade higher on the evening of the 6th – about 19 degrees, at the time and place of the picture.
Mercury’s magnitude at this time is 0.4, a bit brighter than the first-magnitude stars of this region of the sky, Aldebaran, Betelgeuse, and Capella.
After this, Mercury will both dim and fall back toward the Sun, passing in front of it on May 30. Mars, farther off, is now too low to see, continuing to fall back more slowly behind the Sun. Venus is at about the same distance from us as Mercury, but continuing to swing higher each evening as it comes nearer to us.
Fortunately, here on the east coast, early May means a decent chance of clear skies, so I am hoping that I don’t have to travel outside of Virginia to observe it. The last two Venus transits, in June 2004 and 2012, were observable here in central Virginia, but in both cases only for perhaps 10 or at most 15 minutes of time in between clouds. So, barring any stupendous breakthroughs in cryogenics, Mercury is all we got to look forward to for transit action.
On May 30, 2015 Mercury will pass two degrees south of the Sun, effectively but not exactly in front of the Sun. On May 9, 2016 Mercury will pass *directly* in front of the Sun — a transit of Mercury. If you’re on the day side of the Earth during the transit, and you have a telescope with a safe solar filter and a clear sky, you should be able to see Mercury’s tiny dot moving across the face of the Sun. The whole transit will take seven and a half hours, so I will plan to spend the day watching the transit. The transit will already be in progress at sunrise of the west coast of North America, so I’ll have to think about traveling to see the whole transit. I’m already making plans to travel to see the Moon transit across the face of the Sun on August 21, 2017.
The 2016 May 9 transit will be covered in a full page which I have already prepared for Astronomical Calendar 2016.
Yay! I’m looking forward to it. The headline of this blog post just got me thinking about where Mercury will be next May … . I get excited about transits.