We live about two miles away from Harold’s elementary school, where where have to cross a freeway and negotiate four traffic lights and three four-way stops. There are enough obstacles such that we give him a ride to school every day.<br />n<br />nSometimes, I wish we lived further from school. Some days, we end up having good conversations during that ten minute ride, the two of us. Today, for example, was one of those good days. Let me write about it.<br />n<br />nAs we were pulling out, I noticed that the morning sun was hitting a neighbor’s solar panels just right so that the dust was pretty obvious. I mentioned that they should clean the panels occasionally so that the panels were more efficient and generated more power. Harold asked what the panels do, so I answered, they create electricity so we can charge our devices, run the TV, turn on the lights at night.<br />n<br />nThen I was reminded about the rovers on Mars, specifically Spirit and Opportunity, which originally had an expected lifespan of just one hundred earth days or so. The reason for such a short life expectancy is because the planners figured that dust would collect on the rovers’ solar panels and then, no more power. As it turned out, Mars also has wind, which is sometimes strong enough to blow dust off the panels, making them able to continue to generate power, for years, in fact. (Note, however, that only one of the rovers is still operating, Opportunity, over ten years since its deployment!)<br />n<br />nWe then got to talking about if humans, if outside the safety of a space helmet, would be able to breathe, very briefly, the atmosphere on Mars. I replied that no, that wouldn’t be possible for several reasons. One, the atmosphere is really, really thin on Mars; it would be like trying to breathe on earth on a mountaintop that’s over 40,000 feet in elevation (maybe more). Also, the makeup of the atmosphere is different. Our bodies are used to earth’s mix of 79% nitrogen and 20% oxygen. Without that sweet oxygen, we’re done for.<br />n<br />nMars is also very cold. Cold, he asked? Yes, very cold, it’s further from the sun than earth.<br />n<br />nWe then got into the positions of the planets, and how there are huge gaps between some of the planets. He knew of the asteroid belt between Mars and Jupiter, and he also told me about the other asteroid belt between Neptune and Pluto. I know there is a big gap between the orbits of Neptune and Pluto, but I can’t say I was too familiar with a second asteroid belt in that space. Harold insisted that there is, and who am I to refute?<br />n<br />nWe also talked about Pluto’s ‘demotion’ from a planet to a <em>minor</em> planet, the <a href=”https://en.wikipedia.org/wiki/Kuiper_belt” title=”kuiper belt”>Kuiper belt</a>, and how Pluto is believed to be a Kuiper belt object.<br />n<br />nThere were some other bits an pieces that we talked about during that short ride, but it was one of those rides where we actually shared information with each other at a relatively high level. That’s always satisfying.<br />n<br />nWe got to school, a tad later than normal, and I wished him and good day, and he said bye. Sometimes, I wish we lived a little bit further from school.<br />n<br />n<br />n<em>Image attribution WilyD at English Wikipedia via CC BY-SA 3.0.</em>