On my eclipse tour's last night in Xi'an, an ancient capitol of China that was once the world's largest city, our leader told us that he had come across a man with a telescope showing people the planet Jupiter near the Drum Tower, a few blocks from our hotel. My curiosity piqued, I went for a walk through the city's Muslim quarter where the Drum Tower stands, and eventually found a whole fleet of telescopes and a few other surprises.

First, I passed through a large open-air market at the Drum Tower's base that extended down a narrow side street, packed with vendors selling everything from handicrafts to souvenirs to exotic foods; I scored a set of calligraphy brushes I'd been hunting for. On approaching the Drum Tower from the other side, I was surprised to find no less than 5 large telescopes, each with a mirror about 10 inches in diameter). I had a look through two of them, paying 10 yuan (about $1.50) to each of their owners. I'm not sure if they were entrepreneurs or associated with some astronomy club; this blog post (see bottom) leads me to believe the former.

In the first scope I looked through, I got a very poor view, with stray light brightening the image so that I could barely make out the three of Jupiter's Galilean moons that were visible. But in the second scope I tried, the view was much better, easily revealing the moons as well as the prominent cloud belts that encircle the planet.

Before I'd looked through the second telescope, its owner handed me a small, dark slab of glass that reminded me of the monolith in 2001: A Space Odyssey. I had no idea what it was for, and my Mandarin was barely past the "Ni hao ma?" stage. He pointed to the side of his scope, to which he had taped a picture of a solar eclipse, and I realized that he was giving me a solar filter--presumably a piece of smoked glass--through which I could safely view the eclipse, four days hence. (The Sun would only be 90% eclipsed in Xi'an, so we were to move on.)

The expedition had supplied each of us with a pair of "eclipse glasses," with dark filters and paper frames decorated to show a dragon eating the Sun (one Chinese mythological interpretation of a solar eclipse). As it turned out, a motif of clouds eating the Sun would have been more appropriate. During the eclipse's partial phases, the clouds (which soon thickened, and completely obscured our view of the totally eclipsed Sun) filtered out enough sunlight that the Sun was barely visible in the eclipse glasses, but the Xi'an filter nicely revealed the Sun (adding a greenish caste; see photo) as the disc of the Moon took a larger and larger bite out of it. Not bad for 10 yuan.

As I looked at Jupiter through the street astronomer's telescope, late in the evening of July 18, I had no way of knowing that sometime in the hours to come, an asteroid or comet would collide with that planet, leaving a dark blemish that would be discovered by an Australian amateur astronomer the following night. As no one reported the telltale bright flash that the actual impact would make, the collision presumably took place on the side of Jupiter facing away from Earth, to later rotate into view. If the impactor had been just a bit further along in its plunge towards the largest planet, it's possible that I, half a world away from home, would have been in a position to view the collision or at least its immediate aftermath.