Return of the Pale Blue Dot

Want to try your hand at interplanetary communication?  I mean that literally.  Cassini is about to take a picture of the dark side of Saturn. It has done this before, of course, but this time is even more special.  It has been timed so that our own planet will be visible below the great ringed beauty.  The Cassini team has invited all of us to become sub-sub-sub pixel resolution contributors by waving at Saturn as the 15-minute exposure is made.

This is a really a doubleheader.  The MESSENGER mission team, inspired by Cassini’s photo op, realized they could catch images of Earth from Mercury during roughly the same period.  So you’ll have your choice of spacecraft to wave to!  Hey, why not both? 

More details are on the Cassini website, but here are the basics.  The shot from Saturn will commence tomorrow, Friday, July 19^th, at 21:27 UTC, which is 2:27pm in Pacific Daylight Land, where I’ll be.  MESSENGER will grab its photos at 11:49, 12:38, and 13:41 UTC on both Friday the 19^th and Saturday the 20^th.  Attention, residents of Europe, the Middle East and Central Asia!  The MESSENGER camera is your best shot.  I’m just sayin’.

I hope to be standing outdoors at JPL with a group of visiting teachers.  One way for you to join in will be watching a 21:00 UTC (2:00pm PDT) Ustream webcast featuring Cassini mission leaders.  Add your own images on Twitter by using the hashtag #waveatsaturn, or uploading to the event’s Flickr page. Facebook is in on this, too.

The spacecraft images will take a few days to process.  A full mosaic from Cassini may take weeks, but it will be worth the wait.  There’s real science going on here.  With the sun hidden by Saturn’s bulk, the planet’s backlit rings can be examined in terrific detail.  MESSENGER will be in the midst of looking for natural satellites of Mercury.

With Saturn currently about 900 million miles or nearly 1.5 billion kilometers away, you might think this is the longest selfie in history.  Not so.  The original Pale Blue Dot image was taken in 1990 by Voyager 1 when it was more than four times as distant. 

I hope you’ll be one of millions showing your support for planetary science and the spirit of exploration!  Don’t forget to smile.