I went out last night with my youngest for a meteor shower watching party which had been scheduled from 9 to 11 up at the school. It was colder than its been all season, but the sky was clear and the moon was last quarter and hadn’t risen as yet. We bundled up really well, brought out some camp chairs and blankets and a pair of (I thought) decent binocs. As the night went on these became nearly inoperable in the 27-28F temps, and I’ve read that better quality binocs don’t have that problem.
The teacher got the kids organized and looking up and gave some opening remarks before introducing her guest for the night who turned out to be my favorite professor from when I was working on my masters at Stony Brook, Dan Davis! He had brought out two telescopes, both Dobsonians, one an immense 14″ and I believe the other was either a 10″ or 12″ and was busily assembling and collimating them. To collimate basically means to align the mirrors so that the image is as perfect as possible. This video gives you an idea of what is involved (keep in mind this was being done in the dark).
Continue reading “Quadrantid meteor shower and observing session”
We still have a couple months of hurricane season left on the east coast and we recently lost GOES-13, the geostationary weather satellite that used to provide high-quality satellite images of the Atlantic. There was only a 21 hour period of no coverage, but it should serve as a wake up call about how important these satellites have become to us. While scientists were first puzzling over how to get 13 working again, forecasters were forced to use GOES-15 which is positioned west of Alaska. Even though it was put into “full disk scan” mode, GOES-15’s imagery gets significantly worse on the east coast. Forecasters had to combine that data with pass-over images from several POES satellites (polar orbiting sats) to do their east coast predictions. To have the kind of weather (and hurricane) prediction we’ve gotten used to requires good quality imagery well out over the Atlantic where hurricanes form. The GOES-14 satellite positioned at 105W (a good position for observing the west coast) is now functioning as a replacement for 13 since Sept 24th, and if ultimately 13 can’t be fixed, 14 is slated to be moved to a new position at 75W as a permanent replacement. In the meantime, NOAA will have to depend more on aircraft reconnaissance of developing storms so we can expect far less accuracy in hurricane prediction for a while.
Continue reading “East coast weather satellite GOES dark”
I wonder how Hitler would have responded to the following. Dark skin is well adapted to tropical, unforested regions where ultraviolet radiation is particularly intense. Lighter skin makes a person more susceptible to skin cancers from this kind of radiation, making them less likely to survive and outcompete darker skinned humans in these regions. Lighter skin is less of a problem in the North where there is less intense ultraviolet radiation, or in forested regions where humans can live most of the time in the shade of the trees, but darker skinned peoples can live in the North with just as much ease so Caucasians gain no competitive advantage due to skin color in the North. As it turns out, Caucasians are lighter skinned because their bodies produce a defective form of a skin protein Mc1r (melanocortin-1 receptor) which is necessary for the production of melanin. In other words, being Caucasian is actually a bodily disfunction! Some Caucasians from Northwest Europe have completely lost the ability to tan, and instead burn and peel after sufficient exposure to the sun – clearly not a superior condition to NOT burning and peeling, and as it turns out – quite dangerous.
Today’s APOD (Astronomy picture of the day) is of Vesta, a rocky asteroid named after the Roman goddess of home and hearth. Vesta is the second most massive asteroid in our solar system, but the first to be visited by the Dawn spacecraft which finally arrived there in July after launch in 2007 under power of its three xenon ion thrusters.
Yes, I said Ion Thrusters.
Star Trek fans will recognize this as “ion drive” and won’t confuse it with “ion propulsion” a more highly advanced technology not developed until sometime after 2268. NASA was clearly not aware of this semantic difference, but according to their otherwise very informative page, ion thrusters have demonstrated fuel efficiencies of over 90 percent compared to chemical engines which are around 30% efficient. Dawn is the first long range spacecraft to use this technology, (some satellites use it to maintain orbit). It will remain in orbit around the rocky world for most of a year and then will continue on to study the slightly larger dwarf planet, Ceres.
Another view of Vesta from about 3,200 miles distant.
Getting home late tonight we stepped out of the car and looked up Southward to behold the ominous (and luminous) sight of the Moon almost to the full against a backdrop of wispy clouds directly over the house. I quickly made plans with my eldest to meet in the backyard with the binocs for some impromptu sky gazing, and though a night with a nearly full moon isn’t the best time to look we were both so glad we did. Learning how to use binoculars properly takes a little time, but what a payoff! My daughter also recently got new glasses so just having those on was awe-inspiring for her, let alone the close up view the binocs afforded. But the real treat was our view of Jupiter. At the time it was still pretty low in the East, but there weren’t any clouds near it (at first) and after a few minutes of fiddling, I at least was able to resolve two moons. A quick check of Stellarium afterwards confirms that what I had been seeing was Ganymede on the left and the combined light from Europa and Callisto on the right. I didn’t see iO, but the wife claims she did. I’ll include a couple screen shots from Stellarium of what it looked like to us. You know its a great night of gazing when your kid is as excited about it as you are! She even said she wants to study Astronomy more! Win!