🔭 Updates an earlier post to include recent changes and new information. 🔭
Desktop planetarium software helps plan viewing sessions and keep track of the planets and Moon. Many products are available for all computer platforms and smartphones. A Google search yields links to many sources. Open source and free Stellarium is on my desktop computer. It can be customized to your location and has a nice look and feel. For Android and Mac phones and tablets, I like SkySafari. It isn’t free but is inexpensive.
Online planetarium sites are popular and offer many features. Below are highlights of a few I like. With multiple features, a unique look and feel, and different levels of detail, they can help satisfy your curiosity about astronomical events. I welcome reader questions or reviews about using these tools or others you find helpful.
Show me more
Two contrasting headlines about recent climate in the U.S. this spring caught my attention. Both came from NOAA’s National Centers for Environmental Information. The headlines were from the assessments of climate in the U.S. for April and May of 2018.
• The contiguous United States had its coldest April in more than 20 years.
• The contiguous United States had its warmest May on record.
The part of the U.S. where you live might not have seemed unusual. However, we noticed these differences in the midwest. Before examining April and May specifically, we will look at the climate for the year-to-date in the next two graphics. Relative to the period from 1895-2018, the upper plains was below average in temperature for the first five months of the year. The west was above to much above normal with record setting temperatures in the southwest.
Not shown in the graphic, the Alaska year-to-date temperature was 20.7°F, or 4.9°F above average. It was the ninth warmest on record. Western and northern Alaska were much above normal. Record low amounts of sea ice in the Arctic likely contributed to the warming.
Show me more…
🔭 Updates an earlier post to include recent changes and new information.
As an amateur astronomer, I use desktop planetarium software to plan viewing sessions and keep track of the planets and Moon. There are many products available for all computer platforms and smartphones. A Google search yields links to many sources. I downloaded and use the open source Stellarium on my desktop computer. It can be customized to your location and is free. For Android and Mac phones and tablets, I like SkySafari. It isn’t free but is inexpensive.
Online planetarium sites are popular and offer many features. Below are highlights of some I find interesting. Each has multiple features, a unique look and feel, and different levels of detail. They can help satisfy your curiosity about astronomical events.
I have included only a few select sites and links since so many are available. I welcome reader questions or reviews about using these tools or others you find helpful.
Show me more
The eruption of Mt. St. Helens in Washington State 37 years ago was a spectacular event. Upwelling of magma caused the mountain to be forced slowly and strongly from below. On the morning of 18 May, a huge landslide occurred on the north slope face of the mountain. Rock, timber, snow and ice, slid down the face. The event allowed the volcano to release pressure and begin its eruption.
Ash was projected high in the sky and was caught in the high altitude westerly winds. The dense cloud of ash drifted east blocking out the midday sun across the state. Ash settled down on communities causing confusion and havoc.
In the path of the settling ash was Manastash Ridge astronomical observatory run by the Dept. of Astronomy of the Univ. of Washington. Douglas Geisler was working at the observatory throughout the night of the 17th into the early morning hours of the 18th. He said the skies were excellent for telescope observations. He went to bed at about 5 am.
A loud ‘boom’ barely interrupted his sleep. He went back to sleep until about noon. When he got up to go outside, it was dark.
“Yikes! – There is no day. It’s completely black; thick, inky black with visibility ~10 feet (with a flashlight), & it stinks. This is the end of the world.”
In the logbook for the 19th, he noted for the record the sky condition was black & smelly. He also noted he lost 6 hours of observing due to volcano (good excuse, huh?)
He thought he might be the last survivor of the war as he remembered hearing a ‘boom’. He turned on the radio and heard ‘cha cha’ music. Why was the world playing music at the end of the world? Eventually the radio station from Yakima said that Mt. St. Helens ‘blew its wad.’ He was relieved.
It remained dark until mid-afternoon. Several inches of ash settled on the ground. Visibility improved to about 1/2 mile by dusk. He covered the telescope and instruments to prevent damage. He took some pictures of the dome and surroundings thinking he might make a lot of money on his story. But, he never followed through.
A prism of high quality glass sits in a south window above our mantle. It is part of a surplus optical instrument from WW-II. The window crank gives a sense of its 2″x1″x1″ size.
When the Sun is low in the sky during late fall and winter, light through the prism casts a large full spectrum on the wall on the opposite side of the house. This is a closeup of the spectrum. It is always a delight to see the colors move slowly across the wall during the middle part of a sunny day.
Show me more…