by Ted Frimet
how much wood
could a woodchuck chuck
if a woodchuck could chuck wood ?
I bring you tidings of a final essay, as I have spent all of my Shekels from 2017. And have no coin left for another asteroid. I probably have done as much as I can, given the precious tools that were lent to me, by educators, and club members alike.
While researching Elf on a Shelf, I stumbled across Mench on a Bench. I knew it. I should have bought one. Or maybe, I should never have touched the elf. I heard that if you do so, the magic just runs out of ‘em. Or as Bugs Bunny once said to Daffy Duck, “hey doc, No more buwwets ?”
I took a keen interest in a website that manages data, by way of a NASA grant, on minor planets. Asteroids, I have learned, are sometimes referred to as minor planets. So full of ego, was I, to continue to read that a recently captured asteroid, temporarily labeled YY897E1, was observed in the deep of space on not less than four occasions. And was rated at 100% desirable for more data. I took the bait. Yes I was hooked, and knew that I would tire on the line. The magnitude, you see, as at 21.6 v. And I had my doubts that I could find an object that faint.
I broke down the NEO confirmation data into four blocks, of 10 minutes each. And asked for 4 seconds exposure 30 second interval images. Not enough bullets, for ‘ol Bugs. The stellar limiting magnitude, if memory serves me correctly, cut out at around 17. To add mischief to miscalculation, the telescope release times were delayed, and did not match my ephemeris data. I, as Mr. Hopeful (a tip of the hat to one my indoor cats, that is Ms. Hopeful, aka Big Pussycat, aka Maybell – around dinnertime) did spy upon three potential variances in the image cache. A pot of coffee later, and with Digital Sloan Survey in hand, two of the hopefuls were stars – and the remaining minor trailing spark of hope was written off as a high speed energetic particle of other worldly origin. (Ok – maybe it was just from our stratosphere. sigh.).
Last man standing with a few coins in hand, I turn my attention to a list of asteroids for 2018 that would make good mention. And fell in love with 1362 Griqua. Wiki records her as 28 kilometers across. That is 1,000 times the diameter of J2012 TC4, imaged back in the day, when I was drunken with Skynet currency. I had my marching orders, now.
After experiencing the elusiveness of YY897E1, imagine my glee, when Griqua lit up my screen! How would I present this object? Well, two ways of course! Once as static, Griqua smiling back to you at center of screen, while the surrounding stars flew by. And once again, as Griqua sailed thru the night sky, leaving her starlets, motionless in awe.
And then I saw the discrepancy. There was an unintended time delay between image 0 and image 1, of 24 minutes, plus some. Not the two minute interval I had hoped for. I asked the Mench for help, but he simply sat there, on the bench, with nothing to say. What could I do ? Of course, ask the Elf to speak to Mr. Claus, on my behalf! However the Elf was out of magic, and her lines of communication had been cut. No direct line to Santa. Beans!
How much wood can a woodchuck, chuck ? is my euphemism for how fast does an asteroid travel thru space? I couldn’t quite wrap my noodle around ideal calculations with J2012 TC4, or 3200 Phaethon (recently imaged) for linear velocity. However, NASA had already calculated the diameter of Griqua at 28 km, and I knew the time frame from which I took pictures. Teeming with errors, I decided to not use Julian calculations (which report down to fractions of a second) and used vernacular minutes and seconds to limit precision within the boundaries of acceptable error.
Measuring the diameter of each asteroid in frame, I arrive at 8 pixels, rounded due to errors in measurement. So, 28 km = 8 pixels. Taking my time, I arrive at the following:
I have recorded 26.13 pixels from one asteroid location (image 1), to the “last” (image 7), over 765 seconds. Griqua is 8 pixels across, in my image. 26.13 / 8 = 3.266 Griqua units.
28 km * 3.266 = 91.5 km
91.5 km / 765 seconds = 430 km/hr
Now, back to my woodchuck:
There was a jump in imaging between my first and second frame resulting in:
1,445 seconds elapsed between a distance of 48.88 pixel distance (center to center).
48.88 / 8 = 6.11 Griqua units.
6.11 * 28km = 171 km
171 km / 1,445 s = 426 km / hr
Griqua, it would seem, and of course, only at first blush, travels around 430 km per hour. Prepare yourself as the mensch on the bench, just established a toe-hold in the boundless world about the elvish kindred, by virtue of chucking wood at the void. At 430 km / hr, that’s some pretty fast wood.
For the linear velocity portion of the video skip ahead to time frame 2.25. For telescope exposure/filter times click here.
Happy New Year to all club members!