Satellites, Eclipses, and Happy Holidays

As some of you know, I am pretty interested in the weather.  So most days, while having coffee and settling into the office, I am poking around on-line, looking at things like the models that the University of Washington Department of Atmospheric Science make available, looking at weather maps, downloading data and plotting soundings with ROAB and trying to understand what they mean. 

Sometimes, I even load data into Digital Atmosphere and try my hand at plotting a front.   Still a long way to go there but I think it may be kind of like learning to use a psych chart;  you just have to do it and it will eventually come to you.

20203351640_GOES17-ABI-FD-GEOCOLOR-1808x1808But my favorite part of the routine is the time I spend looking at satellite imagery.  I find myself mesmerized by the colored view of the earth and the clouds just hanging there in space.

The images update every 10 minutes and you can even create a little animated loop and watch the terminator and weather systems sweep across the globe, as shown below.


I was doing this earlier this week when my eye caught something.  At first, I didn’t realize what was happening.  But then, it dawned on me (and you probably have already figured it out from the title);  I had just seen the eclipse from the vantage point GEOS West.

I thought it was really cool.  So I created animations for GOES West and East, downloaded them and figured I would share them here.  This first one is from GOES West, which is what initially caught my eye. South America is in the lower right part of the image so watch that area to see the shadow show up.

This one is GOES East, which gives a better view of things since South America is front and center.  I don’t know exactly what the yellow bars that show up at the end of the sequence are, but I think they had something to do with the satellite data set not being fully complete.  Fortunately, the eclipse is in the first part of the sequence.

If you want to slow things down or pause, I made a little video that includes both of the animations with the yellow bars edited out.  You will find it at this link.

If you go to the GEOS imagery page and pick a view, you will discover that there are all sorts of ways to look at the images that reveal all sorts of different things about the atmosphere.   But the one that I love the most is the GeoColor product, which is what was used for the images above.

The image is actually a combination of different satellite data stream to create a very vivid realistic daytime image.  The night time image uses data from different infrared bands to show low liquid water clouds as differentiated from higher ice clouds.  The city lights are from a different static data based and provided to allow you to orient yourself.

To me, it is amazing to contemplate what you are seeing when you see that shadow pass over the surface of the earth; masses orbiting and interacting with each other in a perfect balance.   In the days leading up to Christmas this year, we will have the opportunity to see a different manifestation of that ballet as Saturn and Jupiter come into the closest conjunction they have been in for some 800 or so years.[i]

Saturn and Jupiter Conjunction

Some have even hypothesized that the star of Bethlehem may have been just such an event.

So now, (if you are still reading this) you are thinking O.K. there is the  “Happy Holidays” part of the post title.   And that is in fact part of it.

But, the other part of it is to point out that we did not always have such a spectacular view of our home available to us at our finger tips.  Prior to this time of year in 1968 – specifically December 21 through 27, 1968 – the most remote vantage point had been what Pete Conrad and Richard Gordon had captured for us from 850 miles up on their Gemini 11 mission, which is shown below [ii].

850 miles up 7-s66-54706-b

But on Christmas Eve, 1968,  the crew of Apollo 8 – Frank Borman, James Lovell, and William Anders – captured an earth rise while orbiting the moon; the first time humans had done that.


The image [iii] is, of course, is quite famous;  some have called it

the most influential environmental photograph ever taken[iv]

I tend to agree with that, having seen it with  my own eyes that evening.  That image, and the lunar surface rushing by and the words the astronauts shared that evening[v] are burned into my memory.  It definitely is part of the reason I do what I do these days.

Later that evening – actually, I think in the early hours of Christmas day (EST), this sequence of transmissions occurred (I believe the time stamp is hours into the mission and liftoff was at 7:51 a.m. EST on December 21, 1968):

089:31:12 Mattingly: Apollo 8, Houston. [No answer.]

089:31:30 Mattingly: Apollo 8, Houston. [No answer.]

089:31:58 Mattingly: Apollo 8, Houston. [No answer.]

089:32:50 Mattingly: Apollo 8, Houston. [No answer.]

089:33:38 Mattingly: Apollo 8, Houston.

089:34:16 Lovell: Houston, Apollo 8, over.

089:34:19 Mattingly: Hello, Apollo 8. Loud and clear.

089:34:25 Lovell: Roger. Please be informed there is a Santa Claus.[vi]

If you followed the space programs, the hours an minutes between the Christmas Eve broadcast and the transmissions above were pretty important because the Trans-Earth Injection burn would happen.  This event involved the (single) engine in the service module igniting and accelerating the spacecraft out of lunar orbit into a trajectory that would carry it back to earth.

If the engine failed for any reason, the crew was not coming back.

Thus, the acknowledgement of the existence Santa Clause.

Bill Anders, who took the earthrise picture above often said something along the lines of:

We came to explore the moon and what we discovered was the Earth

Ultimately, I think why I am writing this is to encourage you to take some time to contemplate and fully appreciate that discovery.   I think it’s easy to take for granted in the world we are in.  But I also think it is crucial that we appreciate it.

In her 1976 album Hejira,  in a song titled Refuge of the Roads, Joni Mitchell wrote:

In a highway service station
Over the month of June
Was a photograph of the earth
Taken coming back from the moon
And you couldn’t see a city
On that marbled bowling ball
Or a forest or a highway
Or me here least of all

These days, I think that is an important perspective to keep.   When you look at our pretty little home from the vantage point of space, all of the things that seem to trouble us and divide us become invisible.   And what becomes apparent is that we are all in this together on a beautiful but tiny little life boat.


PowerPoint-Generated-White_thumb2_thDavid Sellers
Senior Engineer – Facility Dynamics Engineering     Visit Our Commissioning Resources Website at

i          Image Credit: NASA/ Bill Ingall

ii         NASA/Dick Gordon; Sept. 14, 1966 – View From Gemini XI, 850 Miles Above the Earth | NASA

iii       Image Credit: NASA/Bill Anders; Apollo 8: Earthrise | NASA

iv       Nature photographer Galen Rowell

v        This link will take you to a recording.  There are religious overtones, so fair warning if you find that sort of thing offensive.   Me personally;  I am probably more spiritual than religious, but the moment was and still is very moving.

vi        Apollo 8 Flight Journal – Day 4: Final Orbit and Trans-Earth Injection (


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4 Responses to Satellites, Eclipses, and Happy Holidays

  1. Dave Mason says:

    Well said David. Happy holidays. #allinthistogether

  2. christina says:

    Hi David, I took your classes on existing building commissioning at the PEC with Ryan what feels like eons ago (was really only 8 or so years ago). I’m no longer working in the HVAC industry, but you, your stories, and your teaching style left a strong impression on me as a young engineer. Just came back to your blog today out of the blue. Reading this last blog post was almost as good as philosophizing with you after class. Thank you for your dedication to teaching and your passion for functional, efficient buildings. Wishing you and yours health and happiness!

    • Hi Christina,

      Nice to hear from you and thanks for the kind words and well wishes. They mean a lot and I really appreciate your taking the time to share them.

      Health and happiness to you also; thanks for reaching out,


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