Last year I picked a red-letter day in space exploration, and took a tour through the Solar System using pictures that were all made on or close to that one day. Since then, the robotic reconnaissance of the worlds has only accelerated. It's time to take another tour.
This time we're looking at October 9, 2013. On that day, a spacecraft bound for Jupiter returned home very briefly for a speed assist from the Earth's gravity. This is what the encounter looked like, as simulated in NASA's Eyes on the Solar System software.
As it swung by at nearly 170,000 kph, Juno listened to amateur radio operators on the ground. It also took advantage of the moment in order to create some beautiful portraits of the home world.
As memorable as the Juno flyby was, the amazing thing is that Juno was by no means the only mission that the Deep Space Network tracked that day. All across the Solar System, our robotic proxies were exploring the frontiers we can't yet cross in person. The following photographs were all made within about 24 hours of Juno's closest approach to Earth.
At Mercury, the MESSENGER orbiter peered from behind its sun shade to glimpse the first world along the edge of its night.
While circling our own moon, the Lunar Reconnaissance Orbiter trained its camera on a "sea" right at the edge of the near side we can see from Earth. It captured the spectacular rays of a geologically young crater that extend for kilometers in all directions.
Several missions were active at Mars that day. From orbit, the HiRISE camera scanned the north polar region, where it imaged a layered cliffside made of ice and dust.
Look closer, and there's a bonus: it looks like the picture was snapped right at the moment that an avalanche had kicked up a cloud of dust.
Meanwhile, a decade into its 90-day mission, on that same day the Opportunity rover was executing commands to examine the local geology at the windswept rim of the crater Endeavour.
Half a world away, the mobile laboratory Curiosity was undertaking an audacious trek across the desert floor of Gale Crater.
Meanwhile, in the deep sky where the Sun shines a hundred times dimmer than at the Earth, the shimmering, golden-colored spacecraft called Cassini turned toward the sixth planet. It saw the rings, the ever-churning cloud tops, and the most enigmatic weather in the Solar System: the polar hexagon.
These missions and several others are at work today, too. You can watch, in real time, as we listen in.
I'll say it again: it's an amazing time to be alive.