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.
SpaceX, the private rocket launching company owned by Elon Musk, has had successes lately with commercial satellite launches. On 1 May 2017, they launched the military satellite NROL-76 from historic Launch Complex 39A at the Kennedy Space Center in Florida. Another major accomplishment by SpaceX is the successful landings and re-use of the stage 1 booster of the Falcon 9 rocket. This has never been done before, not even by NASA. The way I see it, that story deserves some explanation.
Watch this compilation of clips from the most recent booster landing, their 4th. The landing takes place on an unused pad not far from launch complex 39A a short distance up the coast. I wondered what flight path the stage 1 booster took to allow it to return back to this spot near the launch site. Most of its fuel had been used to get it and the stage 2 payload to high altitude, far downrange, and going very fast. The flight needed to be very efficient.
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Launched 15 October 1997, the Cassini Mission is in its 20th year. It reached Saturn and entered orbit on 1 July 2004. Details of the mission can be read at this Wikipedia summary. This post is mostly about the maneuvers by Cassini to change its orbit and make 22 close encounters with Saturn in what is called the Grand Finale. End of mission is scheduled for 15 Sep 2017 when the spacecraft plunges into the atmosphere of Saturn ending a long and brilliant exploration of the famous ringed planet, its rings, and 62 moons.
Clean Room Workers Ready Spacecraft | NASA | 1996
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I follow the blog The Catholic Astronomer from the Vatican Observatory Foundation. I’ve heard of the Vatican Observatory for a long time but never knew much about it. It sits a above an extinct volcanic lake at Castel Gandolfo in the Papal Gardens near Rome.
© Paul A. Zalonski
Very recently, the observatory director and foundation director led a tour of the place. Joining them was Christopher Graney who is an astronomy teacher in Louisville, KY. He recorded videos for his class to see later. His videos are posted here on the blog site.
Scroll to the bottom of his post and click the left of three small images about the history and telescopes. His link will take you to the three videos.
One aspect of interest in the tour was of the women computers who worked there and their machine used to measure stars on the glass plates. It connected well with the work of the women computers in The Glass Universe by Dava Sobel. Those women laid the foundations for many of the important principles used in modern astronomy.
I headed home after attending the public lecture on aurorae by University of Iowa professor Craig Kletzing. One part of his talk included a demo of color emissions from the element oxygen. It is responsible for nearly all the colors associated with aurorae. We needed diffraction grating glasses to see the demo effect such as these.
As I drove home, I noticed the bright crescent Moon. I stopped the car to look through my grating glasses. Once home I set up the camera with the grating over the lens. It was a nice way to end the day.
On 24 January 2004, NASA’s Mars Exploration Rover Opportunity landed and started exploration. It joined the Spirit Rover which landed three weeks earlier on a different part on the Martian surface. The twin rovers were designed for mission lifetimes of 90 days.
Spirit’s last communication with Earth was 22 March 2010 more than six years into the mission. Opportunity is still operating well and continues to return images and data to Earth after thirteen years. It recently completed a marathon of distance travelled. Detailed maps are available here. To celebrate entering teenage, NASA Jet Propulsion Laboratory released this entertaining video about the milestone.
This post is a follow-up to one from a week ago. See below the line break for the original.
Thanks to comments by readers, there are three resources to promote which discuss the need for careful, considered dialogue and planning with regard to our nation’s domestic and military nuclear capacity. Readers shoreacres and Jim Wheeler discussed two resources by Thomas Nichols. The third resource is a recent NOVA program about the nuclear option.
First, what if we could rebuild our nuclear weapon forces from scratch? How should it be done?
Second, read the preface and introduction to the Nichols book No Use: Nuclear Weapons and U.S. National Security
Third, the NOVA program Nuclear Option is available for viewing until 8 Feb 2017.
All three urge bi-partisan discussion by all interested parties. One of the reasons hinges on the need for safety and security in our world today. The other reason hinges on the need for a viable solution to the challenges of climate change and global warming.
I believe nuclear energy should play a role in our future. To not examine the ideas and technologies formed in the 50s, 60s, and 70s which brought us to our current position is foolhardy. The world has changed very much since then.
Nuclear Weapons | Do Accidents Happen?
Have there been nuclear weapon accidents or incidents? Yes, there have been many. We are lucky to not have detonations or major spills of radioactive material. An accident near Damascus Arkansas on 18 Sep 1980 illustrates how a simple event can cause a situation of monumental potential for disaster.
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