Astronomy – Page 60 – A Darker View

Occasionally we get phone calls. People have an astronomy question and decide to call an observatory to get an answer. I would caution that this is generally not the best way to get an answer, Googling the question or looking it up on Wikipedia is much more likely to result in a usable answer. Usually our front desk will politely defer the caller to some other source, Shelly is very good at doing this.

The International Space Station and the docked space shuttle Endeavour

Shelly is also a very nice lady who occasionally takes pity on some caller. Or the caller is very polite and asks very nicely. Often she forwards the call to me, knowing that I can usually answer these sort of questions.

What sort of telescope can be used to view the ISS?

At least the question did not involve aliens or NASA cover-ups, those question would have gotten the polite brush off from Shelly.

For someone who is inexperienced in using telescopes this not the easy place to start. Most of us who have been using telescopes for decades usually do not even try to do this. The space station is quite small and would require higher magnification to see well. It is also moving quite quickly across the sky. The combination of these two factors makes viewing the ISS a real challenge, to put it politely!

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Cleaning a Mirror

Autumnal Equinox

Fall equinox occurs today at 04:21HST. Today there will be little difference between the length of the night compared to number of daylight hours. This is the first day of fall as marked by many cultures in the northern hemisphere.

This year many calendars will mark September 23rd as the beginning of fall, and so it is for much of the world. Here in Hawaiʻi the equinox actually occurs on the 22nd when considering the time zone differences.

2016 Solstices and Equinoxes
	UT		HST
Perihelion	Jan 2	22:49UT	Jan 2	12:49HST
Vernal Equinox	Mar 20	04:30UT	Mar 19	18:30HST
Summer Solstice	Jun 20	22:34UT	Jun 20	12:34HST
Apehelion	Jul 4	16:24UT	Jul 4	06:24HST
Autumnal Equinox	Sep 22	14:21UT	Sep 22	04:21HST
Winter Solstice	Dec 21	10:44UT	Dec 21	00:44HST

Source: USNO data Services

Jacked

Full Moon

Full Moon will occur today at 09:05HST.

This full moon will feature a penumbral lunar eclipse visible across part of Australia, Central Asia, and eastern Europe. No part of this eclipse will be visible from the Hawaiian Islands. No worries here, we are not missing much, this penumbral eclipse involves only a modest dimming of the Moon.

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A Touch of Winter

It is not snow in the image, but rather hail covering the ground and temporarily turning the summit white. A trough rich in moisture is passing the islands, leading to very active thunderstorms and even hail at the summit. We completed segex today, with thunder rumbling outside the dome. The hail melted off in a few hours, pretty while it lasted…

Changing a Light Bulb

How many engineers does it take to change a light bulb?

Arc Lamp Bulb — An arc lamp bulb for the AO calibration source

Nearly every morning I begin the day with reading the nightlogs, a write-up of everything that went wrong in the night on both telescopes. Normally there is nothing I need worry about, or perhaps something to follow up on during the day. But occasionally, not very often, I find a nightlog that indicates I will be re-scheduling my whole day, dropping any previous plans and driving up the mountain.

This is one of those times. A nightlog coded as critical, the Keck 2 adaptive optics system has a slight problem, no output from the white light source, no calibrations, no science. Waiting until after 9am I call the support crew on the summit… Do you know how? No. I wrestle with the thought for a few moments. No avoiding it, I need to drive to the summit.

So how many engineers does it take to change a light bulb?

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SMA

SMA — The Submillimeter Array Telescope in a tight configuration

Cruft

The Keck Adaptive Optics systems are workhorse scientific instruments. Equipment that has resulted in so many great astronomical discoveries. The AO systems have also seen a great deal of improvements and upgrades through the years. New computers, a new wave-front controller, guide star lasers added, new cameras, different science instruments, and much more.

While the new gear has improved the systems dramatically, the result is that there is a fair amount of disused bit and pieces hanging about. Mostly cabling, but more than a few unused boxes of electronic gear are still sitting in place in the racks.

Eventually I just get fed up with it and insist we spend some time getting rid of it. With no AO use scheduled for a while there is a chance to spend a couple days ripping out this pile of cruft. Identifying and removing unused boxes. Following cables to nowhere, wire cutters in hand to snip away the multitude of nylon zip-ties.

We remove three large armloads of cables and other gear, carring the pile down to the electronics lab for sorting through and disposal. Most of it is horribly obsolete, things like KVM’s for PS/2 style mice and keyboards, or cables for old Sun computers. Most of it will simply be thrown out. It feels so good to get it out of AO and to clean up the place a little.

I called this pile of junk cruft, a word that drew funny looks from my co-workers. You don’t know what cruft is? What sort of nerds are you? Sorry, cruft is what I have always called leftover technical junk.

Cruft is jargon for anything that is left over, redundant and getting in the way. It is used particularly for superseded and unused technical and electronic hardware and useless, superfluous or dysfunctional elements in computer software. – Wikipedia

It turns out that the word has a long history in engineering and computer science with a heritage that includes MIT and Harvard. It is indeed the proper word for the detritus that had been accumulating in the AO vault.

Category: Astronomy

Securing the Segment

Viewing the ISS