Today Mercury reaches maximum elongation, the furthest point it will reach from the Sun in the sky and the highest it will be above the sunrise for this morning apparition. The planet is easily visible as a bright, starlike object about 19° above the rising Sun as the twilight begins. Over the next couple weeks Mercury will slide back into the sunrise, heading for superior conjunction on December 7th.
An excellent video showing how pāhoehoe lava flows advance. A flow is a surprisingly complex process. A quick look or photograph will fail to reveal what it going on, it takes time to observe something that occurs this slowly. I have spent hours watching and filming flow fronts advance, totally amazed at what I saw when I really watched…
Time lapse shows the process more clearly than watching in person. It is the inflation of a pāhoehoe flow that shows in a compressed timescale. A flow a foot or two thick becomes six or ten feet thick over the course of a few hours. Also revealed are how other features of the flow form… The ropy surface, the broken plates, the cracks where lava has oozed out. After having watched a flow in process I see old lava flows in an entirely new way.
Below is an old video, filmed over several visits to the lava during the summer of 2010. I have better material now. Some time I need to put it together into a new video. Still, you can see the process of breakout, advance, crust over, inflate, then breakout again.
I have yet to have an opportunity to see an ʻaʻā flow advancing. They move entirely differently. I understand the sound of an ʻaʻā flow is impressive, a moving gravel pile of grinding and falling rock.
You do not see milestones on modern highways. In the US they have been replaced by green, metal markers that number the miles you have traveled. Of course modern vehicles have odometers counting away those miles, distance and years put behind us in the many little journeys of life. Back and forth to work, around the island, daily routine and explorations. In a good life those miles represent both the mundane and little adventures.
I put well over 200,000 miles on my last vehicle. The new vehicle? Purchased with 78,000 miles already on the odometer, thus I can only claim the last 22,000 as mine alone. But this was a Keck fleet vehicle, I put a smattering of the previous 78,000 miles on this truck, either driving or riding up and down the mountain.
A good dive?
There may be a few criteria of a good diving experience. One of the top reasons I would call it a good dive… When the dive results in at least one really good photo.
This fellow was not in a cave, not in a wall, but out on the coral flats, and area not usually associated with great photo opportunities. Out on the flats the light is troublesome, in a cave or under an overhang I can control the light, eliminating the strong blue green hues that ruin so many photos. Under a coral head, I spot a fish just perched in the crevice. He did not move despite six or seven exposures with the camera a foot in front of him…
We have all been watching the lava flow for the past several weeks as it crept ever closer to the homes and businesses of Pāhoa. Not since the destruction of Kalapana in the 1980’s has the volcano threatened so much destruction. This historic plantation town is a special place, a town with a very unique character, a place that preserves some of what makes Hawaiʻi special.
This morning the flow crossed the first road above the town. If the flow keeps the current advancement rate it will be in the town over the next couple days. My thoughts are with the residents of Pāhoa… Stay safe!
The huge sunspot complex remains quite visible. The detail is fascinating in the eyepiece, well worth setting the telescope up again for another day.