The passing of solar system objects near our Sun in our skies should be an unobservable event, but, you, intrepid reading of blogs, may already know our secret for actually viewing these events; we can ‘cheat’ by using the Solar and Heliospheric Observatory. SOHO is designed to look for faint solar wind phenomena near our Sun, which is exciting all by itself. The pages with the SOHO solar viewer is at https://sohowww.nascom.nasa.gov/data/realtime-images.html .
The SOHO spacecraft is a million miles from Earth in the direction of the Sun, and doesn’t have to deal with pesky things like atmospheric turbulence or our Moon photobombing the shot. This kind of photo is hard to take from Earth, unless you have a total solar eclipse (next in the USA in 2024!), which is a good kind of lunar photobombing.
In March 2019, Mercury, Neptune and minor planet Vesta pass through the widest viewing frame, known as C3. The United States’ Navy Research Laboratory has a finder chart for these passes (for some reason, the site is not listed as secure by our browsers, so you may want to skip following this link until we find out what’s going on there): https://sungrazer.nrl.navy.mil/index.php?p=transits/transits_2019 . But, I’ve borrowed the graphic for 2019, right here:
A recent example of using the SOHO viewer, to see when Saturn passed near our Sun from our point of view, is at: https://bkellysky.wordpress.com/2019/01/04/wheres-saturn-january-2019/.
Happy hunting – report results in the comments, if you like!