Tuesday, April 21, 2020

Magnetometer Report for NearSys Station, 20 - 21 April 2020

I produced the following chart from my experimental magnetometer. The magnetometer started recordingvdata at 9:09 PM last night. I wonder if the data looks the way it does because of appliances inside the house turning on and off.

I will leave the magnetometer outside overnight to see what the data looks like. However, the magnetometer is temperature sensitive. Therefore I expect to see changed related to temperature, which I expect will look different from last night and today's data.

We had extremely good air quality last week. There were only four momentary spikes of questionable quality and those only reached the yellow category.

Monday, April 20, 2020

Visibility for NearSys Station, 19 April 2020

Beautiful morning. So it's not surprising the visibility this morning was greater than 50 miles.





Friday, April 3, 2020

The Evening Star and the Seven Sisters, 3 April 2020

Due to a quirk in the orbital periods of Earth and Venus, we observe the Evening Star pass through the Pleiades star cluster (the Seven Sisters) once every eight years in April. The last time was in April 2012 and the next time is in April 2028.

I recorded the image below using a FinePix S7000. The camera was mounted to a tripod to keep it steady during the exposure. The camera was set at its maximum six power optical zoom (I didn't use the digital zoom) and the exposure time was for four seconds (so you can see a tripod us critical for success).

I took the best picture and enhanced it in GIMP by adjusting the contrast and brightness. The image doesn't quite match what I see in binoculars, but it is close. By the way, the glare of Venus is too great for you to see the Pleiades unless you use optical aid, like binoculars.

The Pleiades are 444 light years away and Venus is only 57 million miles away or about five light minutes.

Wednesday, April 1, 2020

Earthquake at NearSys Station, 31 March 2020

Shortly before 6:00, NearSys Station experienced a magnitude 6.5 earthquake near Challis. The earthquake was not severe here, some 140 miles from the epicenter. Nonetheless, it was a powerful shake that left the furniture creaking and chandelier rocking.

My slinky-style seismograph measures vertical displacement best. And when this 30 second long quake struck, the seismograph was left shaking for over 14 minutes. Over 20 aftershocks were detected over the next 21 hours. Aftershocks are still being detected 24 hours later.

The time between the arrival of the P and S wave is on the order of 15 seconds. The P wave arrives first because it travels the fastest. The S wave is slower and if we measure the difference in their arrival times, we can determine the distance to the earthquake's epicenter. Grom what I see on earthquake tables, a difference of 15 seconds is about 150 km, or 91 miles.

Seismogram of the earthquake and many of its aftershocks

The extracted earthquake and first aftershock

Air Quality for NearSys Station, 20 -28 March 2020

NearSys Station experienced poirvair quality briefly this week. This just goes to show you how using a fire place can reduce air quality for your neighborhood.