With the recent hole-in-one landing of NASAs Curiosity rover on Mars, we begin exploring the surface of that planet for the presence of organic materials thought to be essential for life. By organic we mean the chemistry term describing compounds containing carbon. While sci-fi writers toy with the notion of silicon-based life, due to silicons proximity to carbon on the periodic table, we have lots of silicates on Earth, and I do not recall seeing a quartz roach crawling about.
You can barely catch a glimpse of the Red Planet, very low in the southwestern sky. On Aug. 21, it will be 10 degrees above the horizon about 9:20, an hour after sunset. Thats about a fist width at arms length, so you will need a clear horizon to see it. It will be just above a sliver of a moon, and Saturn will be to its right.
The moon will march to the left each night as I start teaching this semesters intro to astronomy class. Once again, I will try to convince the students that the phase of the moon, going from new to full over the next two weeks, is caused by its changing position revealing more or less of its day- and night-time sides. Many students will think instead that the dark part of the moon is Earths shadow, which it is not. Earths shadow has everything to do with lunar eclipses but nothing to do with phases.
This misconception may have its origins in our early learning: As babies and toddlers, we came to understand that things are not seen because something else blocks the view. (Wheres Danny?)
Neurological science has come to believe that it is impossible to have the brain cut the neural connections that store such misconceptions. The best we can do is to develop new connections (memories) of the facts and hope that when we go to recall the real story, these new connections dominate the old.
Good luck with that! I include the standard, multiple-choice lunar phases question on my pre-test as well as every exam after that for both semesters of the course. However, at the end of the year, the success rate settles down to 70 percent and there seems to be nothing that can be done about it.
So, try to catch a glimpse of Mars this week. And, the unshadowed moon!
Daniel B. Caton is a physics and astronomy professor and director of observatories at Appalachian State University. Email: firstname.lastname@example.org. More on this months column: www.upintheair.info.