This will be a short update, but I didn’t want you to think we’ve folded our tent at Jupiter yet. The image illustration at right is amazing, isn’t it? If you haven’t been to Jupiter yourself, I think now you can say you almost have been!

New Horizons is now beyond 6 astronomical units from the Sun and about 1 AU from Jupiter, which is, of course, moving too. We continue to transmit data from close-approach observations made in late February and early March. As of late this week, we have 80% of the mother lode from Jupiter here in computers on terra firma.

We also continue to take data as we fly down the Jovian magnetotail. Our Solar Wind at Pluto (SWAP) and Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) teams are discovering structures in the tail they never dreamed of, including some fascinating periodicities and sulfur ions that originated as neutral sulfur back at the volcanic moon Io. You’ll hear more about this exciting exploration when those teams figure out what it all means.

Meanwhile, our spacecraft team is conducting a series of tests to ready us for our first stint of hibernation, which begins at the June-July boundary. We must update our autonomy/fault protection software to ready it for hibernating through most of July and August, before we wake up the bird for instrument calibrations. The team is also carrying out various spacecraft propulsion and other subsystem tests and some further instrument calibrations.

And while the spacecraft team is busy with hibernation preps, our science team is closing in on a decision about which day in mid-July 2015 we want to arrive at Pluto. We had planned on July 14, but decided to look at surrounding dates for potential, additional science opportunities at Pluto. Considerations range from what terrain we see best on Pluto (each day is different as Pluto rotates over 6.4 days), to where Charon is located relative to Pluto, and where Nix and Hydra will be as well. We plan to make a final decision at a full science team meeting on May 30-31. I’ll let you know what we decide, but I can tell you that after a close look, July 14 is still an awfully good choice. If we move off July 14, we’ll execute a burn this fall to change our speed by 3 to perhaps 30 meters per second (depending on how many days we move the date).

Well, that’s all I wanted to tell you about this time. I’ll be back with more news soon. In the meantime, keep on exploring, just as we do.

- Alan Stern