An illustration of the terrible truth of Panspermia. I bet Phil didn’t include getting smacked with giant space wigglies in “Death from the Skies!”

I speculate that this is a feature akin to Crater Lake, Oregon, USA, where a large volcanic caldera collapsed upon itself (it even has its own “Wizard Island!”). At some later time the lava-filled caldera breached the southern crater wall, forming the tapering outflow channel which overlaid the cracks (which had formed previously due to the uplift of the rising magma plume which spawned the volcano in the first place).

I won’t be proven right/wrong until MESSENGER’s in orbit and can start mapping detailed topography of this region. But I’m waiting on pins and needles (for 2.5 more years).

But what do I know? I’m not a planetary geologist.

Heehee;)

Yes, well, er… that’s what happens when one works as a proofreader for too long — you take things too literally!

You see what I mean!

There is another criteria for planetary status we could use. If you stuck the “planet” in the same orbit as mercury would the “planet” evaporate leaving only a few rocky chunks. I think we could “fail” Pluto on that too.

I originally had “wove”, but it sounded bad. I looked it up, and “weaved” is OK, though not preferred. In this context, I thought it sounded better!

I would have said: Impact resulted in Mercury’s spider webs.

Phil Plait mumbles: Thank you, Mr. Smart Ass!

And oops! The link given in the press release was wrong. I updated it.

1. You are one heck of a lecturer and speaker in front of the camera. I used to do technical instruction from time to time and I absolutely loved it. One time the boss put a video camera in the classroom to capture me. It was a total disaster as I stiffened up, kept my hands clasped behind my back, talk about your wooden personality. I just couldn’t hack it. So my hat’s off to you for doing these videos.

2. Have you ever considered doing this as a sideline and a new revenue stream? There’s an outfit called The Teaching Company that sells DVDs of different courses featuring some pretty high-powered professors. They’re at . I have no affiliation with them but I’ve got a couple of their courses. Just to be clear, these courses are not transferrable or creditable on any transcript – they are for personal enjoyment and enrichment. I’m sure there are other similar outfits as well.

-Tod

Serious question… if Caloris is so large relative to the planet, does it have the effect of making the planet lopsided in some way, much like the moon is lopsided (centre of mass is shifted slightly) ?

Whatever hit Mercury was big, and hit hard.

Oy! My mind is in the scientific gutter!