Archive for July 4, 2016

07/04/2016 – Ephemeris – NASA’s going to light off fireworks at Jupiter tonight

July 4, 2016 Comments off

Ephemeris for Independence Day, Monday, July 4th.  Today the Sun will be up for 15 hours and 27 minutes, setting at 9:31, and it will rise tomorrow at 6:03.  The Moon is new today, and won’t be visible.

There are two astronomical highlights for your Independence Day enjoyment.  The first comes at 11:59 this morning (15:59 UT) when the Earth is at its very farthest from the Sun this year.  Some 1.7% farther than average.  You’re still gonna need your sun screen anyway.  Later this evening, a half billion miles from Earth NASA’s Juno spacecraft will fire it’s rocket engine for 35 minutes to begin to decelerate over the north pole of Jupiter to drop into a long elliptical orbit of that planet.  NASA TV will begin broadcasting the event at 10:30 p.m.  (2:30 UT, July 5) The 35 minute engine burn will start at 11:18 p.m. (3:18 UT, July 5)  What we’ll see is a real-time graph of the Doppler signal from the spacecraft as it slows down to drop into orbit of Jupiter.

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


Juno Spacecraft

The Juno spacecraft. Credit: NASA.

The Planetary Society’s Emily Lakdawalla has more information on How to watch Juno’s orbit insertion at

NASA also has an application in which you can see simulations of Juno’s orbital insertion.  It’s called NASA’s Eyes and can be downloaded from