A Million People in the Air

Jim R 24 Comments

While out for a walk during a recent sunny day, we noticed many passenger jets flying at high altitudes over us. They each have seating for dozens of people. An average of around 200 passengers per plane seems a reasonable estimate. We were curious about how many people might be up in the air at any one time around the world.

There are many flight tracking apps and websites that keep track of the aircraft. A web search of ‘flight tracker sites’ turned up a dozen or more. The one I use is ADS-B Exchange. If you open that link, click on View Map to see the world map of planes in the air. You can zoom into your location. This image below is a screen grab of the world map view.

Here is a screen grab of the zoomed-in view around Los Angeles and Las Vegas. A lot of planes were in the air when I got this image.

In your actual live map, click on any plane icon to see more details about that plane in the left margin. In the right margin, near the top, are two numbers for Total Aircraft and On Screen. Further down are some filters that can be applied to the results in the map. I chose to filter by Altitude. I set the lower limit to 20,000 ft and the upper to 40,000 ft. Most long distance carriers, such as the ones we saw during our walk, are within those altitude limits.

When I viewed the map this morning, the results filtered by altitude showed over 5000 planes flying that high. If there are about 200 passengers per plane, that means 5000 x 200 = 1,000,000 people are in the air this morning. I think that is a conservative estimate. There are several thousand other smaller low-altitude planes all over the world as well adding to that big number.

Wintertime Astronomy

Jim R 10 Comments

Doing amateur astronomy in the winter can be a challenge in the midwest. There are cloudy periods lasting a week or more. When it is clear, the temperatures and winds can be brutal. That is what happened this past week. Six days ago we got 12″ of heavy wet snow. There wasn’t much wind or cold with that storm. Three days later another storm came through. It dumped another foot of snow on most areas. Plus, it was colder and a windy storm. We were under a blizzard warning for the weekend. The wind carries a lot of ice crystals into the air creating beautiful effects like these sun dogs taken by an acquaintance not far from me.

Yesterday I got an email notice that the International Space Station was to pass quite close to the Moon at about 7:34 pm in a possible transit. There was no way I was going outside with my gear where it was -10˚F. I looked for the Moon from a bedroom window. That was going to work. It was about 13˚ above the horizon. The ISS would rise toward it from below. I put the camera on a tripod at the window and started recording as the time drew near. Here is the 10 seconds of video that resulted. It was not a transit but a good catch anyway. The sound on the video is from the furnace vent directly below the camera.

Dial-a-Moon | 2024

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What will the Moon look like on any date in 2024? What will it look like on your birthday? Find out at NASA Dial-a-Moon. An example of what you will see is pictured below for 15 January 2024. Follow the next links to set dates and see views for the northern hemisphere or for the southern hemisphere. Enter any month, day, and time to see a high definition image.

After visiting Dial-a-Moon, scan down that web page for a wealth of additional information and animations about the Moon’s motions and appearance. The images of Dial-a-Moon are made from those of the Lunar Reconnaissance Orbiter (LRO) in low altitude orbit around the Moon since 2009.