Sometimes We Miss

On this date in 1962, the Ranger 3 space probe was launched.

In my opinion, one of the most impressive feats of science and technology, not to mention luck, in recent decades has been the success of the Mars rovers. The small (and relatively cheap) "little data collectors that could" have survived on the surface of Mars for years now, collecting hundreds of times the data originally planned for the mission. In the end, it is estimated that the mission will end because of dust that has settled on the rovers' solar panels. We never even considered they could last long enough for dust to be a problem.

Looking at this sort of success, it's easy to forget just how many times we as humans have tried to reach for the stars and failed. Aside from Apollo 13, which was lucky enough to get its own movie, most failed missions are happily forgotten.

One such mission that we often overlook in the history of space exploration is the Ranger 3. Launched from Cape Canaveral on January 26, 1962, it was meant to fly over the moon taking data on radar reflectivity and surface features, then land and continue to collect more data on the surface itself. It was, in many ways, the direct ancestor of the Mars rovers. Only it missed ... by a lot.

The Ranger 3 was launched by an Atlas-Agena B rocket. The idea was to clear the Earth's atmosphere, make a single course correction, and then ride the forces of gravity for the rest of the trip. It's the sort of calculation that anyone outside of NASA would call then, and many of us would still call today, impossible. But this is the reason you and I don't work for NASA. Their calculations were, in all likelihood, perfectly correct, but a faulty transistor on the rocket threw off its guidance system, and Ranger 3 missed the moon by an impressive 37,000 km on January 28. It then joined the thousands of other small objects orbiting our sun, and it remains out there today, spinning around the same star as us. Maybe someday we'll pick it up, and put it in a museum to remind ourselves that, as smart as we are, we and our technology are not perfect.

Galileo and the Four Moons

On this date in 1610, Galileo Galilei discovered the four largest moons of Jupiter.

Well, to be honest, we aren't sure of the exact date he discovered them. As conscientious a note-taker as Galileo was, we can't quite pin down his first glimpse of Io, Europa, Ganymede and Callisto, but it was this date that he first let anyone else know about them. He wrote about them in a letter.

Although Galileo is still today given credit for discovery of the moons, he did not give them their lasting names. He originally named them after the great patrons the de' Medicis. Nothing curries favor with the boss like naming a planetary body after them. The four lasting names were chosen by Simon Marius, a figure of somewhat less lasting fame than Galileo, who claimed to have discovered the moons at the exact same time. He chose to name them for four of the many, many lovers of the Greek god Zeus (Jupiter in the Roman pantheon). The appropriateness of the names seemingly overcame Galileo's right of priority, and I have to admit I'm glad. I'm usually quite a fan of priority in naming conflicts (possibly the nerdiest of all conflicts, by the way) but I would much rather think of the possibility of life on Europa than ponder the frozen seas of Ferdinandipharus. Seriously. Ferdinandipharus.

Europa, whatever you call it, is one of the most promising places for life beyond Earth in our solar system. Though covered in ice, many researchers believe there may be a subsurface ocean of liquid water. This speculation has, of course, spawned volumes of science fiction, from Arthur C. Clarke's 2010 to the works of Caitlin Kiernan and Dan Simmons.

There were several important consequences to the discovery, whoever made it first, of the four moons. Galileo was a believer in Copernicus' theory that the Sun, not the Earth, was the center of the Universe. He famously and unfortunately paid the price for these beliefs, being basically imprisoned by the Inquisition and forced to recant. What he could not take back, though, was his discovery of the moons. They were the most powerful evidence yet that the Earth could not be the center of everything, as Ptolemy said it was. A few relatively lame arguments were made about the moons and Jupiter having incredibly close orbits, making it only seem like they were revolving around each other when in fact they were both revolving around the Earth, just together. It was a ridiculous theory, but one becomes more amenable to such things at the point of a sword, and geocentrism would remain a while longer.

Still, the discovery of the moons did more than deepen our understanding of our own solar system. It opened up the universe. Many astronomers of the time believed that all such major bodies in the universe had been found, and the discovery of the moons basically legitimized the use of the telescope for finding new things in the sky. It made our universe seem bigger, more mysterious, and more worthy of study than it had before, and we've never really stopped looking up since.

Tomorrow, Probability and Disaster