Hi all unfortunately NASA did not respond to my inquiree about the greatest elongation for Mercury ... here is what Wiki says ...

At both of these times Mercury's separation from the Sun ranges anywhere from 17.9° at perihelion to 27.8° at aphelion.[109][110] At greatest western elongation, Mercury rises at its earliest before sunrise, and at greatest eastern elongation, it sets at its latest after sunset

[109] = Walker, John. "Mercury Chaser's Calculator". Fourmilab Switzerland. Retrieved 2008-05-29. (look at 1964 and 2013)

[110] = "Mercury Elongation and Distance". Archived from the original on 2013-05-11. Retrieved 2008-05-30. – Numbers generated using the Solar System Dynamics Group, Horizons On-Line Ephemeris System

However I do not believe this is correct. Please see my diagram below ...



If Mercury is at it's greatest distance from The Sun which is 69,816,900 km and Earth is at it's closest approach to The Sun of 147,095,000 and doing the math in this right angled triangle yields sine of 69,816,900 / 147,095,000 or 0.47463816 and this gives us an angle of 28.336 so I ask please if this is not correct where am I going wrong ?

Regards
Don Barone



"There is nothing as impenetrable as a closed mind"
and ..." if everything is a coincidence what is the point of studying or measuring or analyzing anything ?" db