Posts Tagged ‘dark’

Watching Sunset on the Moon, and things that go bump in the night!

August 20, 2011

Well it’s a start.  Sunset on the Moon!

This is the time lapse of sunset on the moon, taken at prime focus with a cpc11 with a focal reducer and a canon 60D.  The conditions were less than perfect.  This was about 9 hrs all in, and really quite an infuriating 9 hrs.

Firstly, since my ‘run in’ with the mountain lion, I’ve become VERY twitchy about things that go bump in the night, and would periodically scan the torch around, looking for ‘eyes’.  There was also an amusing part when a piece of paper blew out of the car.  The ‘sudden noise’ in the dark elicited an immediate reaction from me, which to the impartial observer must have appeared quite funny and disproportionate! (twirling around ready to attack the piece of paper…… hmmmm….  time to switch to decaf!)

Not all bad though, amazing what the heightened senses can find!


For some reason the telescope is lousy at tracking the moon.  I think this is to do with the fact that the Earth axis, and the normal of the orbit of the moon are out by about 6 degrees.  Practically what this means is the moon not only moves at a different rate to the stars (that is it goes around the sky in about 25 hours, not 24 like pretty much everything else).  But even with lunar rate, the tracking is poor.  I think the moon is also moving up/ down due to the difference in the normal of the Earth rotation and the moons orbit, and the mount is not smart enough to work this out.  The practical upshot of which is the moon will drift out of the field of view over a period of about an hour, so I had to set the alarm to go off every 20 minutes throughout the night in order to recenter the moon.

Further recentering the frames, taken every 2 minutes in editing is also a pain in the ass.  Thankfully Sony Vegas now has a ‘motion stabilizer’ feature that takes a lot of the donkey work out of this.

This is the finished product!  Well actually, only part of it.  At prime focus the telescope can get the best part of the moon in the frame.  I just selected one crater, as it shows the shadows nicely.

Tracking on everything else is perfect, in that at the end of the evening I dialed up Jupiter, and it went straight to it.  Cute! Never seen Jupiter by the full light of day before!

Sunday 31st (Sodium Boom n beyond)

August 4, 2011

Spent the morning very happily going over the potassium footage.  The whole thing is a symphony of physics and chemistry that eventually I decided it would take too long to explain, so I just put up the explosion footage.

It had been raining in Ridgecrest and this clearly was  a freak event.  The standard greeting in Rigercrest between the notably fat folks seems to be ‘hot enough for you’, and not without reason, I think it’s been over 100C every day I’ve been here.  However for the afternoon I decided I would give blowing up the sodium a go.  Now I have lots of sodium, and the scale and geometry is different.  Eventually I decided the way to do it was to get a stick over a reasonable sized vat, which meant that I could lift up the sodium from a distance, have it swing over the vat, then be lowered in.  Sodium is significantly less dense than water, and so would need to be weighted.  The sticks were typically about 10g, so eventually I wrapped up about 4 sticks in aluminium foil, attached weights to them and lowered them in to the vat from a distance.

Initially the reaction seemed really quite slow, to the point where I was wondering how this was going to pan out.  Indeed it took over 10 seconds before the first ‘explosion’ (compared to about 1second for the potassium experiment).  I, for my part am mostly certain this is related to the metal boiling.  However, when it really blew up (and did so quite convincingly) it really made a mess of the container.  Again, the hydrogen burning wasn’t really even a relevant factor, it’s just the adiabatic expansion of the gas released by the reaction.  In this case 40g gives about 40L of gas.  Thats a lot of gas to release in a 5L container!  On inspecting the aftermath it became clear that large chunks of sodium had been thrown clear of the reaction, not just unreacted, but unmelted!  This for me was a stunning observation!  It shows that whatever the reaction that takes place, the rate that heat is generated at the surface is MUCH higher than the rate the heat can be conducted away from the surface.  Sodium is an absolute bitch for making a mess!  Small amounts of sodium had been sprayed all over the tripod, and stripped the paint.  They had then picked up water to make conc. NaOH, draincleaner which will first turn you skin into soap, before chemically burning you.  The stuff was everywhere!  Cleaned up as best I could (again I was on the inaccessible dirt road to nowhere in my little ravine).  Headed back to LA.  Stopped off to see Lisa n Howard n pick up a shower, which I more than needed.  Initially i wanted to get up onto mnt Wilson early, for sunset, but got chatting to Lisa and that never happened.  It was full dark before I set out on the nightmare trek across LA by dark.  It didnt help that I managed to set the GPS wrong, and ended up on the long drive through the horrific twistiy winding roads of the Wilson range (rt 2).  There had been rain here too, and while the road was all but deserted, top speed was about 40 mph and ‘tire killing rocks’ materialized out of the gloom on a regular basis.  Driving that 20 miles was an incredibly intense experience, ultimately driven by ‘do u want it or not’.  I did, I wanted to get up on mnt wilson and do something on light pollution and LA.  I got there about midnight, and got my piccies!

The Solar System in Motion (LIVE) – it’s going to happen

July 25, 2011

For those who didn’t catch it earlier this year, the ‘global planetary timelapse’ project was rejected for youtubes ‘nextup’ program.

However the idea is still a good one, and it’s going to happen!  So behind the scenes I’ve been putting out feelers, and working out how we are going to make this project happen.

As we are unifying several concepts that have never really been put together like this, doubtless there will be a learning curve.  Different guys, with different kit, trying to get a unified data stream.  Hmmm, tricky!

So I’m now heading up to the dark skies round the back of the Sierra Nevada (GREAT SKY FORECAST!)

http://cleardarksky.com/csk/prov/California_map.html?Mn=light%20pollution

to see what I can actually do with the kit I have.  We will then put the project together in stages.  I think our first attempt will be to do a time lapse of the moon from both the mainland US and Hawaii.  We will then try to get people involved in Australia and further around the world (indeed if you are in Australia, or further round the world (so to speak), please contact me @ thunderf00t@hotmail.com, this project Needs You!).  In the first instance it will probably work best with folks who know pretty much what they are doing, but also I would love to put a project like this together with school kids watching the moons of Jupiter, which could be done with almost any telescope that can track.

Anyways Gentlemen, Ladies!  The Mountains and the Dark Skies Await!

TO INFINITY AND BEYOND!


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