Find out how to enter the contest via New Scientist

The images, which appeared in New Scientist, were taken by the HiRISE camera onboard NASA's Mars Reconnaissance Orbiter.

Zooming in on Mars in glorious 3D [New Scientist]

It's hard to quibble with their picks for best movies and books. Being mostly Brits, the New Scientist group put Hitchhiker's Guide To The Galaxy at the top of the novel heap. Iain M. Banks would have won, but his vote was split among a few of his books. (Including Feersum Enjinn. Really?) Frank Herbert's Dune also came close to winning. The best movie, according to the NS crew, was Blade Runner, followed by 2001: A Space Odyssey, Solaris and Serenity.

The "worst" lists might be a tad more controversial. The worst SF books include 3001, Arthur C. Clarke's fourth and final book in the Space Odyssey series, and L. Ron Hubbard's Dianetics. The worst films were The Blob and David Lynch's Dune. Several people apparently also voted for The Matrix (the original) for worst film, but others named it one of the best. One person said of The Matrix:

It has one of the worst backplot elements ever: using people as power sources. I could write an essay on how ludicrous that is.

Finally — and here's the part where some people may disagree violently — the New Scientist staff named Primer the "most incomprehensible" science fiction movie.

"Well worth watching," said one of our editors, "though you might be excused for wondering if it makes any sense at all."

You can vote for your own favorite books and movies, and give your reasons, at this link. Or you could just write a diatribe about why Primer really does make sense, if you watch it eight times. Shape-shifting robot image by Mondolithic Studios for New Scientist. [New Scientist]

USA Today, New Scientist, the awesome astronomy blog Bad Astronomy and the BBC and Nature and just about every sciency news outlet all have items devoted to the centennial. But they disagree on what the Tunguska Event was. USA Today calls it an "impact,' but Bad Astronomy says "air blast" and says there's no evidence anything hit the ground. New Scientist has posted a video in which their reporter circles Lake Cheko nearby the blast site in a helicopter and speculates whether it's the smoking gun of an impact.

What's going on here? Tunguska is probably the most heavily studied impact/air blast/space rock encounter on Earth and we know almost nothing about how it happened. It's also hard to say how likely it is that it will happen again, though one scientist's guess isn't comforting:

In terms of risk to Earth, astronomer David Morrison of NASA's Ames Research Center says a Tunguska-magnitude strike could happen once every two centuries and a bigger impact, a "civilization-threatening" million-megaton strike, could happen once every 2 million years. Even though astronomers have spotted more of these nearby asteroids in the last two decades, the estimated odds of an impact have actually declined, as Morrison notes in a May issue of NEO News, his asteroid newsletter.

If Morrison's right, we've got at best another century to learn as much as we can from Tunguska before another similar event hits home — maybe less. And in the mean time, we'll have plenty of close calls reminding us that we are basically sitting ducks unless we start doing something about one of the greatest threats to our survival as a civilization.