From Mars to New York City

From Mars to New York City

From Mars to New York City

Bad Astronomy
The entire universe in blog form
April 14 2005 10:58 AM

From Mars to New York City

OK, that title is a stretch. I'm going to New York to give a talk about Mars, but it's not NYC, it's actually Suffern, NY, to attend the Northeast Astronomy Forum (or NEAF) star party. I'm the keynote speaker, and I'll be dissing claims of giant cities and faces on Mars. I love giving that talk. It's fun -- and gratifying -- to show exactly where some anti-scientists are misleading the public. Plus, there are some old friends who will be at NEAF and it'll be good to see them again. Also, I'll be swinging by the Hudson River Museum planetarium in Yonkers, NY to give my general Bad Astronomy talk, too. You can find out times and locations by going to my calendar page.

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Speaking of Mars, my old friend Jim Oberg, who is a space enthusiast and historian and sometimes NASA consultant, pointed out to me an interesting shot from Mars this morning. It's a picture from the Opportunity rover, and it appears to have spotted a small crater (actually, two of them). The bigger crater is only 20 centimeters (8 inches) across, and the one in the background is a mere 11 cm (4.5 inches) across, making it the smallest ever seen on the surface of Mars!


Craters are formed when a meteor smacks into the ground (after that, it's called a meteorite). Now, what most people don't know is that smallish meteoroids (what we call the actual chunk of rock before it hits the round) actually don't come screaming in like you see in science fiction movies. In reality, they slow way down while still high up in the atmosphere, and then fall freely after that. They might hit the ground at a hundred miles an hour or slower depending on the situation.

a cropped image of two small craters on Mars

In this case, it really looks to me like something small (fist-sized?) hit the sandy surface of Mars at a pretty slow speed, making that sand pit you see in the picture (click on it to see the higher-resolution, full size image). The feature to the left of the bigger crater looks like the spray you'd expect from such an impact, blown a bit by the wind. The surface around the crater is clearly sandy, and sculpted by winds.

If this is true, it may be Mars' youngest crater! And it may not be around for long; the winds will eradicate it soon too. Most interestingly, it may have a small meteorite at the bottom of it! It's hard to know if these features are really young (like days old) or hundreds of years; the ages of features are very hard to determine. But that spray-like feature to the left of the bigger crater makes me think these guys are really young.

This situation is being discussed on the Bad Astronomy Bulletin Board. If you're interested, join in!