Bob Moler's Ephemeris Blog

Ephemeris for Tuesday, May 29th. Today the Sun will be up for 15 hours and 16 minutes, setting at 9:18, and it will rise tomorrow at 6:01. The Moon, at full today, will rise at 9:21 this evening. | Jupiter is not only the largest planet, but the largest appearing planet pretty much all the time. Venus can look larger when it is a thin crescent about to or having just passed between the Earth and the Sun. Mars, because of its small actual size, that of half the Earth varies greatly in distance, and at its closest appears about half the size of Jupiter in telescopes. Jupiter’s great mass is the key to reasonable travel times of spacecraft to Saturn and beyond. A spacecraft sent to catch up to Jupiter will be accelerated with respect to the Sun into a faster trajectory to arrive at their destination sooner. New Horizon’s trip to Pluto would have taken 13 years, that’s 3 years longer without Jupiter’s gravity assist.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

New Horizons trajectory as of last April showing the effect og Jupiter’s gravitational assist. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.