As the NFL season gets into gear (Go Bills!) it’s time to mention football’s deep connections with astronomy.
The 1927 Broadway musical Good News, which gave us the popular song “The Moon Belongs To Everyone”, is about the division in college life between sports and astronomy, as the male lead of the play tries to skip out on astronomy class to help the school team win the football game.
The area of a football field is often used as an astronomical scale, to point out that the International Space Station is about 1.3 yards shorter than the length of an American football field, or to use various kinds of fresh fruit to simulate the size of the Solar System (not to scale.)
One of my favorite asterisms that isn’t included in the Starry Night gallery for SciDome planetariums so far is the Winter Football. There is a Winter Triangle asterism that is drawn between the bright winter stars Betelgeuse, and Sirius and Procyon, but the Winter Football is much better. If you can imagine a shape drawn between Sirius, Procyon, Pollux, Castor, Capella, Aldebaran and Rigel, it looks roughly football-shaped. For the full conversion, the stars that make up Orion’s Belt can be the stitching. The open-source nature of Starry Night allows the user to create new asterisms like this.
To illustrate the Winter Football on SciDome, download this zipped folder with three files: Winter Football.txt is a short code file that describes the lines drawn between these stars, and the label of the asterism. This file was built using the same template used by Dr. Bradstreet in his Spitz Institute lesson about building custom asterisms.
The second file is a .PNG slide of a cartoon football with a transparent background. For extra verisimilitude, after the stick figure of the football is highlighted on the sky, ATM-4 can be used to bring up the details of the football itself.
The third file is an image with the Winter Football asterism highlighted, showing the sky as it will appear during Super Bowl LII on the 1st Sunday in February of next year.
To use this file in an updated Starry Night Dome 7 for SciDome, it should be added to the folder location:
C:\ProgramData\Simulation Curriculum\Starry Night Prefs\Sky Data\Asterisms\Winter Football.txt
In older SciDomes it may be necessary to load it onto folders on Preflight and Renderbox computers in two separate steps. Please contact me at Spitz Support for details.
The football slide can be used from an appropriately named subfolder of your Preflight desktop shortcut Slides folder. It should work well in semitransparent mode.
All of these uses of getting sports fans interested in astronomy carry no risk of personal injury.
48 years ago last week Apollo 11 landed on the Moon. There is another anniversary last week that seems appropriate to mention at this point: On July 20th of 1925 the greatest scene in American legal history took place, and it was an astronomy lesson.
You’re probably familiar with the play Inherit the Wind, which was based on the Scopes Monkey Trial. In the summer of 1925, more specifically on July 20th, on the courthouse lawn in Dayton, TN, Clarence Darrow had William Jennings Bryan on the witness stand to respectively challenge and defend the state’s Butler Act that prohibited public school teachers from denying the Biblical account of the origin of humanity.
Darrow and Bryan were agreed on the terms of the Earth being a sphere, and that the Earth orbits around the Sun and not the other way round. Therefore it was necessary for them to interpret the biblical passages that seemed to indicate that the Earth was flat and that the Sun stopped at midday for Joshua.
Illustration of Erastothenes’ method by CMG Lee. CC BY-SA 4.0
That the Earth was round, and that the Earth was turning and the Sun was at the axis of the solar system was not difficult to accept in 1925. People were familiar with Eratosthenes’ 3rd-Century-BC experiment in Egypt to estimate the circumference of the Earth (252,000 stadia.) They were also familiar with the great American novelist Washington Irving’s biography of Christopher Columbus, which laid out Columbus’ theory of the roundness of the Earth and his discovery of America obstructing the route to India.
That the Earth was round was also not difficult to accept in the 1480s when Columbus solicited the crowned heads of Europe to fund his voyage to India. It’s just a simplification of Washington Irving’s biography of Columbus to say that Columbus was trying to prove that the Earth was round and that his opposites held that it was flat. In the 4th chapter of the biography, the author puts Columbus in front of the School of Salamanca where he is criticized for the way he contradicts classical dogma from Saint Augustine in the 4th Century AD concerning the “Doctrine of Antipodes“.
In modernity, the antipodes are the geographic point opposite one’s position on the globe, but these medieval Antipodes were the mythical people supposed to inhabit the southern hemisphere who walked upside down (antipode meaning “reversed feet.”) but Saint Augustine did not dispute that the Earth was round:
“As to the fable that there are Antipodes, that is to say, men on the opposite side of the earth, where the sun rises when it sets to us, that is on no ground credible. And, indeed, it is not affirmed that this has been learned by historical knowledge, but by scientific conjecture, on the ground that the earth is suspended within the concavity of the sky, and that it has as much room on the one side of it as on the other: hence they say that the part which is beneath must also be inhabited. But they do not remark that, although it be supposed or scientifically demonstrated that the world is of a round and spherical form, yet it does not follow that the other side of the earth is bare of water; nor even, though it be bare, does it immediately follow that it is peopled.”
Columbus’ critics in the Inquisition, if any, subscribed to dogma that the Earth was round but that human civilization was limited to the temperate zone of the northern hemisphere by the Torrid Zone at the equator. That there was a corresponding southern temperate zone in the southern hemisphere, but that humans created in Genesis could not exist there because the Garden of Eden was in the north and the Torrid Zone was impassable or nearly so. That navigation to get there wasn’t easy because there was no North Star in the south, and the Doldrum Belt made headway under sail to the opposite end of the Earth impossible. The 1st-Century-BC Roman writer Cicero had written about the impassable Torrid Zone in an item called the Dream of Scipio, which is a good basis for an old-timey planetarium show in itself.
“Moreover you see that this earth is girdled and surrounded by certain belts, as it were; of which two, the most remote from each other, and which rest upon the poles of the heaven at either end, have become rigid with frost; while that one in the middle, which is also the largest, is scorched by the burning heat of the sun. Two are habitable; of these, that one in the South—men standing in which have their feet planted right opposite to yours—has no connection with your race: moreover this other, in the Northern hemisphere which you inhabit, see in how small a measure it concerns you! For all the earth, which you inhabit, being narrow in the direction of the poles, broader East and West, is a kind of little island surrounded by the waters of that sea, which you on earth call the Atlantic, the Great Sea, the Ocean; and yet though it has such a grand name, see how small it really is!”
It is true that Columbus was trying to sail around the world to reach India, and that he had underestimated the circumference of the Earth due to a conversion error from Eratosthenes: by the 15th Century, the value of 252,000 stadia was remembered, but the value of a stadion was uncertain, and Columbus used the wrong value. Therefore the Earth seemed smaller, and globes of the Earth from that period show the East Indies on the western edge of the Atlantic Ocean.
Columbus was convinced that the Torrid Zone was not a barrier to travel. Earlier in his career he had sailed to West Africa, almost to the Equator. The first European transit of the Cape of Good Hope (which is in the southern temperate zone) into the Indian Ocean was by the Portuguese navigator Bartolomeu Dias in 1488, two years after Columbus’s first unsuccessful examination at Salamanca.
This 1492 globe of the Earth is under a Creative Commons licence, so feel free to demonstrate it via its own API. It could be converted and wrapped around the Earth in Starry Night, but I don’t feel ready make the final product available for SciDome at this time due to the rights.
However, there are lots of ways to use SciDome to demonstrate that the Earth is round. The upcoming total solar eclipse is one event that is not easy for flat-earth believers to explain, when its occurrence is so accurately predicted with established science. Performing Eratosthenes’ experiment in SciDome is not difficult, by displaying the sky above his two observing stations in Alexandria and Aswan at local noon on June 21st with the Local Meridian switched on with graduations.
Now that we have established that the roundness of the Earth was accepted by both sides in the 1925 Scopes Trial, and that the roundness of the Earth was accepted by both Columbus and his critics (admitting serious gaps in the knowledge of both sides) and by the ancient Greeks, I hope that we can help elevate current concerns about the Earth being flat. I understand that a large billboard was recently used in suburban Philadelphia next to the freeway to state “Research Flat Earth”. And when we argue against modern flat-earth believers, we should not compare their belief to Columbus’s critics, and commit another simplification of the actual story.
Great Red Spot cloud detail from Juno’s extreme close approach. Credit : NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran © cc nc sa
One of the astronomical highlights of last week was the pictures returned by the Juno spacecraft orbiting Jupiter when it zipped over the Great Red Spot at an extremely low altitude (8000 km.) Although the JunoCam camera on this mission was an afterthought for public outreach purposes and not a research experiment, the camera has returned some data that can be amazing when processed, and shows no signs of stopping yet, despite Jupiter’s harsh radiation environment.
To simulate this mission in Starry Night Version 7 on a Spitz SciDome planetarium, a couple of changes need to be made, even with recent updates. But with those changes made, you can simulate this flypast in Starry Night, and also think about using some of the real camera images from Juno on your dome as slides with ATM-4.
Firstly, we need to update the Space Missions file Juno.xyz. Starry Night V7 may already have a version of the mission path, but that is the *planned* mission. An anomaly in Juno’s rocket engine led to a revised mission plan with a different path. The original path does not include a periapsis over the Great Red Spot on the date in question, July 10th. To update the mission path, download this zipped folder, unzip it, and move the contained file Juno.xyz to the following location:
C:\ProgramData\Simulation Curriculum\Starry Night Prefs\Sky Data\Space Missions\Juno.xyz
This change is only made in one networked location to affect both computers, to avoid tediously installing it on Preflight and Renderbox in two steps. Files added to the “ProgramData” Sky Data folder will override files with the same names added to the old-fashioned Sky Data folder in the folder “Program Files (x86)”. The “ProgramData” structure exists so that V7 users no longer need to tediously make changes to Program Files on either computer.
Secondly, the position of the Great Red Spot needs to be updated. Jupiter is not a solid body, and the Great Red Spot has a tendency to drift, and its drift rate has a tendency to change, generating an accumulating error. So it’s not practical to just use the GRS as the index for the fixed period of rotation of Jupiter that is mapped out by the surface texture in Starry Night. The value of the drift is currently about +5° per month, and the current value of the drift is about 271° in Jupiter System II longitude. (Last week I was using a value of 269° and that also came out pretty good: 269° represents the value during the Juno encounter.)
To edit the value in Starry Night V7 for SciDome, locate the following file and open it using Wordpad (not Notepad:)
C:\Program Files (x86)\Starry Night Preflight\Sky Data\JupiterGRS.txt
You may recognize that the code inside is a little odd: Double slashes in odd places. If you are familiar with the coding, these slashes take on added significance. They should each represent the beginning of a new line of code that should be ignored by the program.
The only part of the file that is read by the program is the line that does not begin with two slashes. Please edit the file if necessary so the text is as follows, and the value is updated:
// Enter the mean longitude of the Great Red Spot on the following line. Visit
// the Starry Night Pro website at http://www.starrynightpro.com to get the
// latest value.
Then save the file into the ProgramData folder as follows, in a single step:
C:\ProgramData\Simulation Curriculum\Starry Night Prefs\Sky Data\JupiterGRS.txt
Once again, saving in this location means it’s not necessary to save changes on the other computer as well.
Artist’s rendering of the Juno spacecraft.
There is a 3D model of the Juno spacecraft in SciDome version 7, so you ought to be able to simulate its swooping down on the Great Red Spot in different ways: A long view of Jupiter with the Juno “Mission Path” turned on and the spacecraft labelled as a dot, or also flying alongside the spacecraft 3D model as the GRS looms on the limb of Jupiter overhead.
If you are using Starry Night Version 6 for Scidome, you can still place the attached Juno.xyz in the Space Missions folder of the original Sky Data folder on both computers and chart the updated path, but there is no 3D model of the spacecraft available. There is a separate 3D model that represents the asteroid (3) Juno, and they could get mixed up.
Because the GRS will continue to drift, you may wish to return to make subsequent edits to JupiterGRS.txt. The drift currently accumulates +5° per month, but because the drift rate can change, I recommend doing one of two things:
1) Now that you have the Juno simulation of what will probably be the best and closest images of the Great Red Spot for our lifetime, don’t make any further changes to the GRS value. Further edits to the drifting value will start to “break” the position of the GRS during the Juno flyby on July 10th, if you have built an ATM-4 automation out of it.
2) Continue to update the GRS position to represent reality based on observations, not predictions to avoid accumulating drift error. The current System II longitude of the GRS is kept up to date in a couple of places on the Internet, such as CalSky.
It is possible that Juno will have another encounter with the Great Red Spot on one of its remaining orbits, but the period of its orbit around Jupiter is 53 days. In multiples of 53 days the GRS position value will change by multiples of 9°, with some accumulation of error, and the orbital period of the spacecraft is not an integer multiple of the rotation period of Jupiter. Let’s wait and see.
Novae and supernovae are among the most energetic phenomena encountered in the galaxy. Planetarium educators can simulate a number of historical nova and supernova events on SciDome using Starry Night Dome Version 7.
The following 10 transient objects can be investigated in Starry Night 7’s “Historical Supernovae” database on’s :
- SN 1987A (Progenitor: Sanduleak -69° 202)
- Supernova 1680 (Cassiopeia A)
- SN 1604 (Kepler’s Star)
- SN 1572 (Tycho’s Star)
- SN 1181
- SN 1054 (Crab Nebula)
- SN 1006
- SN 393 (G347.3-0.5)
- SN 386 (G11.2-0.3)
- SN 185 (RCW 86)
Each of these supernova simulations behave in one of two ways on the dome.
The supernovae of the years 1987, 1604, 1572, 1181, 1054 and 1006 in the Common Era were all relatively well-studied when they were visible, and their positions have been correlated with current supernova remnants. These objects are best treated in SciDome: if you look at the sky on the date they appeared and in the correct position, toggling backward and forward several days, the “Guest Star” phenomenon makes the supernova pop into existence, flare up slightly, and then fade away over the course of several months.
The supernovae of the years 1680, 393, 386 and 185 were not well-observed at the time we estimate they exploded due to interstellar dust blocking their light, the difficulty of keeping reliable extremely old observing records, etc. However, some unconfirmed observing reports claim they were observed, and their positions correlate well with supernova remnants or pulsars detected with X-ray telescopes. With no firm dates or estimated brightnesses, it’s appropriate that their positions should be marked, but these four objects do not flare up and then dim out like the first six. There are also photos of the supernova remnants docked in position over these transients in Starry Night.
How about adding objects to this database manually? That’s not so hard, and there are several candidates that have similarities to historical supernovae (although the above ten are the only recorded historical supernovae that have been as bright as the brightest stars).
Artist’s conception of a white dwarf accreting hydrogen from a larger companion
If a supernova is a star that explodes completely, a nova is a star that is only partly exploding. There are a few different theories to describe the processes in a nova star. The most common is that a white dwarf star and a normal star are orbiting each other, and the normal star is close enough to deposit some outflowing gas on to the surface of the white dwarf. The gas builds up on the surface of the white dwarf star until it becomes unstable and explodes. The white dwarf star survives the explosion. These novae can even re-occur once the gas builds up again.
Today is the 99th anniversary of the appearance of the “Victory Star”, also known as Nova Aquilae 1918 or V603 Aquilae. For several days this star was the brightest nova in the age of the telescope, magnitude -0.5, as bright as the brightest stars. It faded back to obscurity quickly. It was known as the Victory Star because some saw it as a portent of the end of the Great War. Also, in an extreme coincidence, it appeared on the same day in June 1918 as a total eclipse of the Sun was seen from coast to coast across the United States.
The file that encodes the Historical Supernovae database is in the Sky Data folder for Starry Night 7 on both Preflight and Renderbox. This feature is not available in Starry Night 6. To make a change, both files need to be edited in an identical fashion.
Here is the code that can simulate the Nova 1918 star by pasting into a new “11th” paragraph:
<SN_VALUE name="00011_Mag_Field_BackGround" value="6.00000000000000e+0, 1.04124631531834e+1, 1.00000000000000e+0">
<SN_VALUE name="00011_Name" value="Victory Star 1918">
<SN_VALUE name="00011_ObjectSource" value="V603 Aquilae">
<SN_VALUE name="00011_ObjectType" value="Supernova Remnant">
<SN_VALUE name="00011_RA_Dec_DistanceLY" value="2.82229166667e+2, 0.058412861111e+1, 8.10000000000000e+2">
<SN_VALUE name="00011_Width_Height_PositionAngle" value="4.33363094776427e+0, 4.33363094776433e+0, 3.60000000000000e+2">
<SN_VALUE name="00011_VarMagStartJulian_VarMagPeakJulian" value="2421752.5,2421752.5,0.0">
<SN_VALUE name="00011_VarMagChangeJulian_VarMagEndJulian" value="2421753.5,2422000,5, 0.0">
<SN_VALUE name="00011_VarMagBefore_VarMagAfter" value="11.0, 11.0, 0.0">
<SN_VALUE name="00011_VarMagPreChangeFitParams_1" value="-1,-1.9936204147E-4,6.9776714514E-4">
<SN_VALUE name="00011_VarMagPostChangeFitParams_1" value="-1.988359647,2.9499496875E-1,-1.6722461742E-3">
<SN_VALUE name="00011_VarMagPostChangeFitParams_2" value="3.9382638857E-6,-3.2343556849E-9,0.0">
The subsequent data line with the tag “Layer_NumberOfObjects” still has the value=”10″, and this value needs to be updated accordingly to 11.
Alternately, you can download an edited copy of the file, unzip it, and install it. If you feel you need a little guidance in installing it, please contact Spitz Support.
The Right Ascension and Declination (RA and Dec) co-ordinates of the new star have to be entered in decimal hours and decimal degrees. The values in the line with the tag “00011_RA_Dec_DistanceLY” are accurate to put the nova in western Aquila several degrees above the asterism of stars that makes up the “foot” of the Eagle.
Some of the above values are just copied from an earlier part of the file, but the observing period, expressed in Julian dates, is shorter than for a supernova. There are only 248 days between the date 2421752 (representing June 8, 1918) and 2422000 when we can estimate the new star had dimmed below the threshold of visibility.
The Homunculus Nebula, surrounding Eta Carinae
There are several other nova stars that can be shoe-horned into this database. For example, the extremely massive star Eta Carinae is currently quite dim and surrounded by an emission nebula, but it is studied so well now because for many years in the mid-19th century its brightness fluctuated wildly up and down, and for some time it was the 2nd-brightest star in the sky.
If future predictions are just an extension of history, perhaps we can use SciDome to get ahead of a possible nova that could flare up in about five years from now. KIC 9832227 is a contact binary star in Cygnus, like the one on the cover of Dr. Bradstreet’s Spitz Fulldome Curriculum Volume 2, and a prediction was made in January of this year that at some time in about 2021 or 2022 the two stars will coalesce together and outburst in brightness. Because the two stars are whirling around each other every 11 hours, due to uncertain mixing and modeling, the error bars make it difficult to accurately predict this “future historic nova”, but it could happen, and we can even try and get the drop on it.
Witnessing a total solar eclipse could change your life. Unpredicted eclipses have changed the progression of historical events. The unexpected environmental effects of a sudden darkness at midday can be very unsettling to people and animals alike.
On July 29, 1878, Thomas Edison observed the total eclipse of the Sun as part of Henry Draper’s Expedition to Rawlins, Wyoming Territory. (Although this year’s total eclipse will pass through Wyoming, the City of Rawlins will be some distance south of the total path this time.) Edison was there to test a new invention that could detect infrared light and estimate the temperature of objects remotely, and he planned to try and estimate the heat of the Sun’s corona while the solar photosphere was blocked by the Moon.
Edison’s preparations for the eclipse were not as cautious as they should have been. Because total eclipses happen close to home so very rarely (2017 is the first year that the totality has appeared in US skies since 1979), and due to the practicalities of 19th century life, most astronomers arrived at the observing site early to uncrate their heavy observing equipment and build observing shacks, and mix concrete to make steady piers. Edison arrived with a few days left before the eclipse, without time to build a protective structure, so he used the existing shelter provided by a chicken coop. On eclipse day, as the sky darkened, the bewildered chickens literally came home to roost, disrupting his observations.
Illustration of Edison’s Tasimeter
Edison named the infrared-detecting device his “tasimeter”, and he was trying to break ground in a new scientific field in competition with the director of Pittsburgh’s Allegheny Observatory, Samuel P. Langley. Instead of letting Langley test the tasimeter’s eclipse performance alongside more proven devices such as the thermopile, Edison tried to “scoop” the competition with his solo work, and failed.
Although Langley also failed to estimate the heat coming from the solar corona with his thermopile, less than a year later he had invented the first bolometer, which is commonly used today in its most refined designs. Langley’s bolometer was so sensitive that it could detect the heat produced by a cow from a quarter of a mile away.
Although the temperature of the Sun’s corona has since been measured with bolometers, the reason why it is so hot – about 1.5 million Kelvin, considerably hotter than the Sun’s surface (5800K) – remains a theoretical problem in physics to this day.
Therefore, if you want to simulate an eclipse, or to prepare for the real thing, don’t neglect the auditory experience. Consider all possible distractions that could disrupt observations in advance, and avoid them. If you are standing near a farm in Wyoming, as the darkness approaches the sound of confused barnyard animals will reach a crescendo.
The new book American Eclipse offers a more in-depth view of the Solar Eclipse of 1878, following the trevails of Edison, planet hunter James Craig Watson, and astronomer Maria Mitchell.
“On the Total Solar Eclipse of July 29th, 1878”, George F. Barker, Proceedings of the American Philosophical Society, Vol. 18, pp. 103-113, 1878. ( https://archive.org/details/jstor-982766 )
“Eclipse Vicissitudes: Thomas Edison and the Chickens”, J. Donald Fernie, American Scientist, Vol. 88, No. 3, May-June 2000. ( http://www.americanscientist.org/issues/pub/2000/3/eclipse-vicissitudesthomas-edison-and-the-chickens/1 )