Today, June 30, marks the centennial of the Tunguska event, the only instance in recorded history of a very large object striking the Earth. By sheer good luck it struck in a mostly uninhabited region of Siberia, at a spot so remote that it was 19 years before scientists were able to study it firsthand. NASA’s Jet Propulsion Laboratory has a good piece on the event.

The Tunguska object may have been only about 120 feet across, but it laid waste some 800 square miles of forest and registered on seismographs as far away as Britain. Much, much larger objects have struck the Earth in the more remote past. Greg Easterbrook reviews some of that history, or rather prehistory, in the Atlantic by way of exploring current thinking in scientific circles about the prospects for more such events (see Earth impact hazard) in the future. Read it if you’re thinking that you’ve been sleeping too soundly lately.

But, as it happens, there’s good news from out there as well. Mars has water, in the form of ice. On top of that (literally as well as rhetorically), it has soil that seems to be very like Earth’s. This means, quite simply, that humans could live there. Not merely visit; live, as in “Where do you live?” “Me? Oh, I live on Mars.” It would be a little different from living on Earth, to be sure, but it can be done. It ought to be done.

You know what would make for excellent summer reading this year? Ray Bradbury’s The Martian Chronicles, followed by Robert Heinlein’s Red Planet and Isaac Asimov’s The Martian Way. If you just can’t abide science fiction, the latest scoop from the Phoenix lander also comes from JPL. It’s a good idea to keep up with developments there.

As it happens, it was also one hundred years ago that Percival Lowell published Mars as the Abode of Life. What he had in mind was native Martian life. More particularly, he believed that what he called the “canals” on Mars were evidence of intelligent life. Better tools for observing the planet have long since put paid to the notion of irrigation canals on the planet, and there is so far no other evidence of any kind of life, much less any of life of a social, building, civilized sort. But it’s still very early days in Martian exploration.

I’ve been telling my wife for years that if the opportunity to go ever comes my way, I’ll take it. She looks at my gray hair and just smiles. That only adds to my frustration. I’ve been waiting a very long time, and it doesn’t look like it’s going to happen to me. But the first human to set foot on Mars is very possibly alive right now. Whoever you are, bless you for your good fortune.

Politics may make strange bedfellows, but these days, who a politician associates with is treated as an indication of both character and policy.  Barack Obama has made it clear that he is running against the policies of “Bush/McCain” and has tried to tie the latter firmly to the former in a number of contexts in hopes that Bush’s unpopularity will rub off on the Republican nominee.  This task is simplified, of course, by McCain’s willingness to tie himself to Bush.

More peculiar is McCain’s new strategy.  Associated Press reporter Beth Fouhy’s article, discusses all the ways in which the McCain campaign is trying to associate Obama with Jimmy Carter.  Apparently, the hope here is that Obama will be tarred by Democratic failures past.  Fouhy quotes McCain as saying, “Senator Obama says that I am running for Bush’s third term…It seems to me he’s running for Jimmy Carter’s second.” 

As tactics go, this one is puzzling.

For one thing, if McCain is concerned that he is vulnerable on the age question, referencing events that occurred nearly thirty years ago is hardly the way to counter any age-based criticism.  Second, as Fouhy points out, the Carter presidency isn’t likely to resonate with young voters, who are more likely to think of Carter as a Nobel winning ex-President who does international relief work than as the man who brought us windfall profits taxes.

But Fouhy does indicate what the Republicans might be thinking: according to former Bush spokesman Ari Fleisher, “Anything connected to Jimmy Carter gives Jewish voters the heebie-jeebies.”  This is a key constituency for Democrats, and Obama, who already has problems with Jewish voters—problems that may well matter in the crucial state of Florida—may be hurt by such a parallel.  Obama’s actual policies are in that instance less important than the implicit claim that Obama is Carter and thus is somehow bad for Israel. 

The difference between these campaign tactics is that McCain has tied himself to Bush; Democrats are right to underline exactly what that might mean (although they should be careful to note both the areas of disagreement between the two as well as where they agree).  Obama, on the other hand, has not endorsed Carter’s actions in the Middle East nor has he claimed Carter as a model for his political life. McCain’s tactic is thus somewhat disappointing.