Blogs / Bad Astronomy

This is TOTALLY HAWESOME: an avalanche on Mars was caught in the act by the HiRISE camera.

This picture shows the billowing dust cloud from an avalanche of ice and dust along scarps — sheer cliffs — near the north pole of Mars. To give you a sense of scale, the cloud is about 180 meters across, and about the same distance from the base of the cliff.

Holy cow.

You can see the cliff in the middle of the picture. It’s 700 meters high (2300 feet!) and slopes at about 60 degrees; that’s pretty close to vertical. To the left you can see white carbon-dioxide frost (which is evaporating as spring ensues in the Martian northern hemisphere) at the top of the cliff.

If my (very) rough calculations are accurate, it would take a rock about 20 seconds to fall from the top of the cliff, and would hit the bottom at about 70 meters/second, or about 150 miles per hour. Look out below!

You can read lots more about this on the HiRISE page.

Sidenote: after the disappointing news from HiRISE this weekend, I feel a lot better about this. Totally amazing. I might even say ground breaking.

Update: The HiRISE blog has a more personal take on this as well.

Welcome Farkers! Well, everyone but aerojockey.

Wow, some antiscience claims are so weird it’s a wonder anyone can take them seriously.

Take this blog post about the image here, for example. In just a few words, it manages to get nearly everything wrong. A lot of it is in Japanese, but some is in English:

A man is in the photograph which the Mars explorer Spirit (it stopped transmitting data in 2004) sent.

First, puhlllleeeeze. A man? It’s a tiny rock only a few inches high. It’s only a few feet from the rover! Here’s the image from NASA. As usual for antiscience nonsense, they point to a press release image with no indication of when it was taken, or what the original image is. There are thousands of Spirit images, and I have little desire to comb through them looking for this one (though it appears to be early in the mission; it’s still on the landing accouterments).

Second, Spirit stopped transmitting data in 2004? Well, kinda. It did stop, but then it started again. We’re still getting good stuff from both the Spirit and Opportunity rovers on Mars. The blog post seems to phrase it that way on purpose, to make it sound like Something Mysterious Happened.

Now, I don’t read Japanese, so this may be a misunderstanding on my part. Are they just pointing out something funny looking? Maybe. FWIW, the site appears to be about weird images and such. But I see so much of this, and there is no lower limit to the dumbosity of such claims, that it just makes sense to figure on the lowest common denominator.

Anyway, the image itself is, of course, yet another example of pareidolia, our ability to see patterns in random shapes. That does look like a guy hanging out on Mars, enjoying the 0.01 Earth atmospheric pressure, the 98% CO₂ air, the subfreezing cold, and of course, just being four inches tall. Martians are pretty short, it seems. And patient, given its pose.

Tip o’ the tin foil beanie to BABloggee piotr slisz.