Now you will feel the firepower of a fully armed and operational Mars rover

Bad Astronomy
The entire universe in blog form
Aug. 19 2012 3:18 PM

Now you will feel the firepower of a fully armed and operational Mars rover

The Mars Curiosity rover unleashed its laser beam eye today, zapping a nearby rock dubbed "Coronation".

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!  

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[The "Before" picture of the hapless rock. I await the "After" eagerly. Click to endeathstarenate, or grab a 10,000 x 2400 pixel image.]

[UPDATE: Here's the "After" picture!

The background image is from the Curiosity NAVCAM and shows the region around Greedo Coronation (you can see the rover's shadow on the left). The zoomed region in the circle shows the area of the rock targeted by the laser just before the laser hit it (you can see the edge of the rock on the right side of the zoom). The final zoom at the top shows the pit zapped into the rock by the laser pulse.]

This isn't mad science! It's cool science.

OK, well, hot science.

Here's the deal: when atoms and molecules absorb energy, they can re-emit that energy as light. The nifty part is, each type of substance emits a different color of light, making it possible to identify them. This is called spectroscopy, and we use it in astronomy all the time. Many objects like gas clouds and stars emit light naturally. We just have to observe them and pick out the signatures of the different chemicals in them.

For a Martian rock, though, we need to dump some energy into it to excite those substances. And that's why Curiosity has a laser on board. It can zap a rock with a short, intense pulse of laser light, and the rock will respond by glowing. A spectrometer - a camera that can separate light into individual colors - then observes the glow, and scientists back home can see what the rock's made of. It's like DNA-typing or fingerprinting the rock, but from 150 million kilometers away.

Reports are the laser worked perfectly, blasting away at the rock with 30 one-megaWatt pulses (lasting 5 nanoseconds each!) in a span of about 10 seconds. Scientists are poring over the results now, and hopefully we'll hear more about this soon.

I just wish they had named the rock Alderaan.

Image credit: NASA/JPL-Caltech/MSSS; NASA/JPL-Caltech/LANL/CNES/IRAP



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