To pick up on Megnut’s and Damien’s memories of the 1986 Challenger explosion on its twentieth anniversary:

When it happened, I was in Grade 8, a space-crazy kid filled to the gills with Star Trek and histories of NASA, and the deaths of seven astronauts was more than just a shock. I found out at the noon hour — I’d come home to make myself lunch and had flipped on the television for background. I was stunned, riveted — but of course, I had to go back to school, where I could think of little else.

At that time the Winnipeg Free Press was published in the afternoon, and I had a paper route after school. It was late that day; in a rare move, the paper had stopped the presses and remade the front page, which now read, in the biggest type I would see until Gorbachev was ousted in a coup, “Shuttle explodes.” Later that night, as I was collecting my paper money from my customers, I couldn’t help myself from talking about it with them — or with anyone.

It might be that for my generation — those of us who were children then, in our late twenties or early thirties now — it was our Kennedy assassination, our Pearl Harbor, our 9/11: the event that brought us to a collective halt.

(I live-blogged Columbia’s destruction three years ago.)

When I was editing regulations at the Justice department, one of the earliest files I was handed made it illegal to point a laser beam at an aircraft. At the time I thought it was hilarious: don’t fire a fricking laser beam at a plane! The Dr. Evil Regulation. Not laughing any more. Holy shit.

Just sent the following letter to the editor of the Globe and Mail about this article about the comeback of the American alligator, which I would have enjoyed more if it had been a bit more accurate.

William Illsey Atkinson’s article about the comeback of the American alligator (“He’s Back,” July 3) contains two statements of fact that require correction and clarification.

First, to say that alligators consider their own offspring a delicacy, or that they practice cannibalism as a form of crocodilian birth control, is not quite accurate. Alligator mothers guard their nests and protect their young for the first year; the young alligators will call for their mother when they feel threatened. Crocodilians are among the few reptiles that show parental care. Alligator males, on the other hand, have no such compunctions, and will certainly prey on younger, smaller alligators if they are abundant, even if they are blood relations — and that might serve, indirectly and unintentionally, as population control. Perhaps that is what Mr. Atkinson meant, but the article may leave a different impression.

Second, calling alligators omnivores is at the very least ambiguous: they are omnivores in the gustatory sense (in that they will eat all manner of animals, including fish, molluscs, reptiles, birds and mammals), but they are not omnivores in the strict biological sense. Like all modern crocodilians, they are decidedly carnivorous.

Atkinson is apparently a technology consultant; what’s he doing writing about alligators? (Then again: what’s an historian like me doing messing around with snakes? Fair enough.)

More on the American alligator.

Fewer elk, more vegetation. When wolves were reintroduced to Yellowstone National Park in the 1990s, it meant big changes for the Park’s ecosystem.

Although the jury is still deliberating the effects of wolves, early evidence strongly suggests that the canids are unwitting restoration biologists. By simply doing what they do — mainly preying on elk — they are visiting great changes on the Yellowstone ecosystem. Many of the changes are positive for those things humans value, and for experts to accomplish some of these same goals would be hugely expensive.

Reducing the numbers of elk allowed vegetation long suppressed by elk grazing to begin coming back, and that had a cascading effect on other species dependent on that vegetation. And, since wolves are the only predator capable of bringing down a full-sized cervid, their reintroduction was beneficial to scavengers, too. Via Rebecca’s Pocket.

The mayflies in Gimli, Manitoba were bad enough for me: some mornings in summer you’d discover that they’d covered every horizontal surface overnight. And you’d be picking them off your body throughout the day. One or two I could handle; thousands, I couldn’t. But that pales in comparison to cicadas. Brood X is emerging again after 17 years. It’s enough to make an entomophobe consider his travel plans very carefully. More via Google News (via Oliver, whose original link has expired).

Why should I go to the trouble of tracking down and blogging all the news and photos from NASA’s Mars landers when there’s already a blog out there that covers that very thing? Have a look at Mars Rover Mission Blog.

The Stardust probe performs its flyby of the Wild 2 comet today. It will collect samples from the cometary tail and return to earth in January 2006.

A Globe and Mail article uses the fact that tonight Saturn will be closer to Earth than it has been since 1975 as a segue into the arrival of the Cassini-Huygens probe at Saturn (and Titan) in July. Also mentions a Canadian astronomy magazine, SkyNews. (I’m starting from scratch, here.)

Bob and Ann are friends with reptiles and a telescope. I wrote Bob with advice on getting started. While he’s dubious about the entry-level refractor in question — he says that they’re frustrating to use — he recommends as a starter Exploring the Night Sky by Terence Dickinson. Now that’s a young-adult title, so I spelunked a bit on Amazon to find a couple of other beginner titles that may be more suitable, also by Dickinson: The Backyard Astronomer’s Guide and Nightwatch: A Practical Guide to Viewing the Universe. Will investigate. More suggestions welcome.

Jen gave me a 420×60-mm refractor telescope for Christmas. We’d been discussing getting into backyard astronomy again — both of us were interested as children, but neither of us had the hardware to do much about it — and this entry-level scope will give us the opportunity to try it out. Unfortunately, neither of us seems to have the astronomy books we had as kids, so we’ll have to start from scratch again in that department. Time to do a little browsing.

In the meantime, there’s a ton of astronomy software out there. I have, or had — time to go rifling through boxes — a copy of Redshift that should run on Jen’s old Windows laptop. As for Mac software, it’s fortunate that Applelust has been providing saturation coverage, thanks to the interests of its contributors: Night Sky, KStars (revisited), Starry Night Pro, Stellarium, Equinox, AstroPlanner, and more.