Juno is not doing science yet, but it's less than a year away from orbital insertion now. I've learned that some of the changes that they made to their orbital plan at Jupiter had to do with concerns over the spacecraft's going into safe mode during the Earth flyby -- twice. Jupiter is going to be interesting...

Cassini's recent activities have included lots of encounters with icy moons. A particularly close one is coming up in a week, when it will zoom past Dione at an elevation of only 474 kilometers. Although the camera will be imaging, the primary focus of the Dione flyby is gravity science; as Jason Perry explains in his Cassini Looking Ahead article for Rev 200, the science team is interested in determining whether Dione's relatively dense interior is differentiated into an icy mantle or rocky core, or not. Cassini will follow the Dione flyby with more distant imaging of Tethys and Enceladus. Later on this year, there will be three close Enceladus flybys: two in October, and one in December. These flybys are all exciting, but they're all bittersweet; increasingly, the mission is doing its last close flyby of target X, Y, or Z. The spacecraft will shift its orbit to an inclined one -- making close flybys of moons rare -- in January. The mission will come to an end in about two years, on September 15, 2017.

There are no spacecraft exploring or cruising to Uranus and Neptune, so next we skip on out to New Horizons, which is (as of the moment that I write this text) nearly 33 million kilometers beyond Pluto, a distance that increases at pretty much the same rate that it did before the flyby -- about 1.2 million kilometers a day. While I was on vacation, only a few new photos appeared on the raw image website, the first five pictures from Departure Phase 1. That's because we're in a planned image drought period, when New Horizons is transmitting the so-called "low-speed" data set and all the spacecraft telemetry. According to what I was told before the Pluto flyby, image transmission will not begin again until September 15. Images that arrive before close of business on September 15 will be released on September 18; anything that comes in the week after that will be released September 25. However, it was also hinted to me that New Horizons might possibly be commanded to return an image or two between now and then. We can hope, but don't expect anything until late September.

Which brings us to the last, distant travelers, the Voyagers. They're still traveling, roughly three times farther from the Sun than New Horizons is, well beyond the outer edge of the Kuiper belt. To answer a frequently-asked question, the two Voyagers will always and forever be farther from the Sun than New Horizons, even though all three are on escape trajectories and lightweight New Horizons left Earth faster. The Voyagers gained more velocity from their multiple giant-planet gravity-assist flybys than New Horizons, which only received one boost, from Jupiter. (Pluto is too small to have affected New Horizons' velocity substantially.) In fact, it's not clear that New Horizons will still be communicating with Earth by the time it reaches the region of space that the Voyagers are now exploring, the boundary between the heliosphere and the interstellar medium. But there is a lot to learn from New Horizons as it probes the region between Pluto and its eventual last-contact point, wherever that might be.