steve cross loves music and science

This animation shows how NASA’s next Mars rover, called Curiosity, will get to its destination. The mission is schedule to launch late this year and if all goes as planned, 8.5 months later we’ll start learning more about Mars than ever before. This rover is the first we’ve sent to specifically look for evidence of life, both past and present. This video is the first I’ve seen that shows every aspect of how the rover will arrive on the surface. Getting a probe safely on the surface of Mars is much harder than you might think- it’s actually the hardest aspect of the whole mission. Mars has a very thin atmosphere, so not only does the initial entry NOT slow the probe down nearly as much as a thicker atmosphere like Earth’s would, but also the atmosphere renders parachutes almost pointless, because in order for a parachute to slow the probe to a safe touchdown speed they’d have to impractically massive in size. In both cases, the thin air makes the slowing mechanism much less effective. For Curiosity, NASA came up with this “sky-crane” landing process that is simply amazing. The engineering and technology required to pull this off simply can’t be overstated- it’s both magnificent and terrifying at the same time. I say terrifying because one tiny glitch or mechanical failure could cause the rover to crash into the surface, land sideways, or even miss Mars altogether. Every minute detail of the mission must be executed with absolute precision and perfection. In the current economic climate, failure of a mission this expensive would be a catastrophic blow to NASA’s unmanned mission programs, and we likely wouldn’t return to Mars’ surface again for many years. But with the huge successes of 2004’s twin rovers Spirit and Opportunity and 2008’s lander Phoenix, it’s safe to say NASA is getting pretty good at this. (Via Universe Today)

Another interesting tidbit I felt compelled to share: people with blue eyes (such as myself) don’t really have blue eyes. In fact, our eyes are actually pigment-less, and the same effect that makes the sky blue makes our eyes look blue. In a nutshell, irises have 3 layers and people with brown eyes have pigment in all 3. People with blue eyes have pigment only in the back layer, while the front layers have no color. However, those front layers also have tiny particles in suspension that scatter blue light (due to its shorter wavelength) more readily than other colors. This is the same thing that happens in the atmosphere and causes the sky to appear blue. As we age, those particles tend to get larger and scatter a larger portion of the light spectrum, thus our eyes look less blue and more grayish the older we get. (Via i09)