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The Eclipse You Didn’t See

This week’s lunar eclipse was seen by by thousands of people, but simultaneously there was an eclipse that was much harder to see.  Had we been standing on the surface of the Moon, we would have seen the Sun silently glide behind the black Earth, leaving only a broken, fiery ring – all the sunrises and sunsets happening around the world.  APOD released a rare “movie” of such an eclipse taken by Surveyor III, a small craft that landed on the Moon in 1967 in preparation for the Apollo missions.  The APOD/R.D.Sampson version had a few flaws I knew I could fix, or at least lessen:  vertical striping (probably photos taken of a tv screen), and low contrast (perhaps because increasing the contrast would have brightened the stripes).  What you see here is my version.

Solar Eclipse From the Moon.  Credit:   NASA, Surveyor 3; Acknowledgement: R. D. Sampson (ECSU)

Solar Eclipse From the Moon. Credit: NASA, Surveyor 3; Acknowledgement: R. D. Sampson (ECSU)

Flaws remain.  There’s only 4 frames in low-resolution black and white.  This color (or colorized?) image hints that different versions of this data exist or existed.  The Lunar Orbiter Image Recovery Project (LOIRP) has been rescuing data from original tapes, leading to dramatic improvements in image quality.  But Surveyor III was a lander and LOIRP is focused on orbiters?  I can only hope that someone will improve upon my version using a better data source.

Lolo Complex Fires Blow Up

Lolo Complex of fires from Aqua satellite, 2:00 MDT 8/19/2013, courtesy NASA/GSFC, Rapid Response

Lolo Complex of fires from Aqua satellite, 2:00 MDT 8/19/2013, courtesy NASA/GSFC, Rapid Response

The Aqua satellite happened to capture a picture of the Lolo Complex fires at exactly the same moment they “blew up in perfect conditions,” according to the Missoulian.  I had to stitch together the version above from the edges of this image, and I didn’t bother to do any spherical correction or anything, so you may notice a few weird artifacts.  The 22-mile Canyon Ferry Lake in the lower right corner can be used for scale.

The Geminids of 2012

Twin Geminids visit Orion and a pair of pines

Things have gotten pretty busy since the kid started going to preschool, and the website has suffered from neglect.  It seems like the only thing I can make time for is the occasional meteor shower.  And so here are the Geminids, in photos taken from the same mountain pass as the Perseids in my previous post.  I like the Geminids.  They are bright, slow-moving, yellow, and clumpy.  Clumpy is not a technical word, it is my own description.  I found that meteors in this particular shower were far more likely to occur in pairs, appearing virtually simultaneously and in the same area of the sky, than any other shower I’ve seen.  That fact that I was able to capture two in the same 20 second exposure appearing near the same trees should attest to that.  It is not lost on me that the radiant is in Gemini, the Twins.

The Perseids of 2012

Perseid over Idaho, 2012

The night sky is beautiful but generally isn’t dynamic.  Other than the slow rolling of the entire sky as the night progresses (as if the stars were affixed to a sphere), there’s very little movement.  Until you see the bright flash of a meteor.  And a meteor shower can turn the sky into a show.  The Perseid meteor shower may be easier to see than most.  Its radiant is in the constellation Perseus, making it visible to most people in the northern hemisphere, where the majority of the Earth’s population resides anyways.  It starts in mid July and peaks August 11th or 12th.  August nights are longer than June or July nights, affording more time to view the shower, but are also warm enough to make lying or sitting still for long periods of time comfortable.  The shower’s large footprint on the calendar makes it easy to coordinate viewing around a busy schedule.

And this year the Perseid viewing should be good.  The peak nights happen to occur on a weekend when the Moon will be a waning crescent that only appears late – on the 12th it rises a few hours after midnight and won’t reach its highest point in the sky until well after the sun has risen.  Unless you have to contend with forest fire smoke or clouds, it could be grand.

Is there a special technique to viewing a meteor shower?  Here I will avoid insisting that you keep scientific records (time, apparent magnitude, constellation), and in fact will assume you are not particularly interested in photographing them (expensive SLR camera on a tripod).  Make sure you have beverages and snacks.  Warm clothing, blankets, or sleeping bags may not seem necessary on a summer night, but ideal viewing conditions are in areas with no clouds and low humidity, and thus radiational cooling and a cold night.  Consider bringing a reclinable chair, cot, or air mattress.  Seek the country – city lights are anathema to good viewing.  Binoculars and telescopes are pointless unless there are other things you are planning on looking at.  Don’t set overly-optimistic expectations:  even at peak, one meteor a minute is the likely rate.

And now you’ll have to decide where to point your face.  If a straight line is drawn through each meteor trail, all such lines will merge at a point called the radiant.  Experts agree that looking directly at the radiant is not the best place to look.  The closer a meteor starts to the radiant, the shorter its trail will appear to you, although paradoxically it means the meteor’s true path was pointed more directly at your head than others.   But after discussing the radiant, opinions diverge.  The advice at Spacedex is simply to “look approximately half way up the sky facing northeast…. Looking directly up at the sky or into the radiant is not recommended….”  These people are wrong.  Halfway up the sky in the northeast is  where the radiant in Perseus will be, at least for the early night, so they’ve told you to look at the radiant and not to look at it in the same paragraph.  Unfortunately the northeast is also the direction the moon will be rising in later, and you don’t want to ruin your night vision by looking at that.

Theoretically, to see the longest meteor trains, you should be looking 90 degrees away from the radiant.  However, there are other factors to consider.   Near to the horizon, the increased thickness of atmosphere leads to greater light scattering, decreasing the brightness of meteors there slightly but also increasing the amount of background light, thus leading to decreased contrast between meteor and sky and poorer viewing.  Also , if you are looking towards the horizon, part of your field of view is of the ground, and meteors don’t appear there.  Most of your field of view should be filled by sky.  So just after sundown when Perseus is close to the horizon, you should be looking straight up.  As Perseus rises  in the northeast, you should consider looking slightly southwest and as the night progresses toward dawn look more to the west.  If you get bored of the meteor show, consider looking at Perseus.  Below him you will see the Moon and Jupiter, and later at night even Venus, all in the same area of sky.

The Eye of Horus

The family had been in the car all day.  We were returning from a funeral in Minnesota, where the weather had turned cold and cloudy to match everyone’s mood.  We were now in South Dakota, heading West on I90.  The horizon had been as gray as the rest of the sky, but it start to change slightly.   It turned into a blue thread, then opened up into a yellow ribbon.  The cloud layer did not envelope the Earth.  It had an edge, and beyond it was the promise of clear sky.  I stopped the car to photograph it.

Land does not meet sky

The Light At The End of The Tunnel

The yellow color was a sign that the sun was low and about to set.    The cornfield was not the most exciting scenery, and we were still hundreds of miles from home, so I got back in the car and continued driving.  I knew that at some point we would either break free of the cloud or the sun would drop through the gap between cloud and ground.  I was not disappointed… Continue reading →