07/30/2015 – Ephemeris – Pluto’s enigmatic atmosphere

Ephemeris for Thursday, July 30th.  The Sun rises at 6:26.  It’ll be up for 14 hours and 44 minutes, setting at 9:11.   The Moon, 1 day before full, will set at 6:45 tomorrow morning.

The last image released last week from the New Horizons spacecraft was a stunning one.  It was Pluto backlit, showing a glow completely around the planet, the atmosphere, showing layers.  Also when New Horizons went behind the planet and again went behind Charon from the Earth’s point of view.  Beams of radio waves from seven of the antennas of NASA’s Deep Space Network were sent toward Pluto and New Horizons four and a half hours earlier.  The spacecraft turned its antenna toward Earth and listened.  As the radio waves passed through the atmosphere of Pluto they were refracted and distorted giving clues to the state of the atmosphere.  First takeaway is that Pluto’s atmosphere appears to be collapsing with its increasing distance from the Sun.

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

Addendum

Looking back at Pluto backlit by the Sun from 1.25 million miles. Credits: NASA/JHUAPL/SwRI.

Click here for more information on the above image.

Data from the Alice ultraviolet instrument when Pluto occulted the Sun. Credits: NASA/JHUAPL/SwRI.

Click here for more information on this Alice observation.