What are Testudo, Frederici Honores, Sceptrum Brandenburgicum, and Officina Typographica?

In essence, they're losers, suck ups, obsoletes, also rans, or former star formations. They just didn't have what was needed to grace our night skies. Most of the 88 constellations linking the 2,000 or so stars we're able to see with the unaided eye were named after mythological creatures and beasts by the ancient Greeks and Arabs. However, appellations of some of the constellations generally visible from only the Southern Hemisphere are relatively modern and were often named by early explorers and seafarers. Sextans, Telescopium, Reticulum, and Octans, for instance, are all navigational instruments, while Vela, Carina and Puppis are the sails, keel and poop deck, respectively, of Argo, the great sailing ship of the Argonauts. Interestingly, even though parts of the ship made it into the sky, the entire ship didn't -- Argo Navis is another failed constellation.

Turdus Solitarius (the solitary thrush), Machina Electrica (the electricity generator) and Tarandus vel Rangifer (the reindeer) are a few more of the approximately 30 now defunct or "never made it" constellations. Of course, some of these so called constellations were obvious attempts to name a star collection after a person who could prove useful to the namer. If King so and so was listed as an official constellation, recognized by all the great astronomers of the day, His Majesty would be puffed up even more than usual. As a result, perhaps a few gold doubloons would end up in the pockets of the keen-eyed and astute astronomer, or sailor, who recognized a likeness of His Royal Highness in the Heavens above.

Some of the "newer" star formations were simply a means to fill the sky with artificial lines. Most of these interlopers didn't usurp existing patterns, instead they were positioned in nether space -- connecting the dots of the fainter stars we can barely see. The brighter stars were of course the first ones claimed in the naming game.

By themselves, star fields aren't much use to astronomers. Most of the constellations are too big to see all of their stars at the same time using magnified viewing. Rather, the constellations are references for dividing up the sky -- basically tools for more easily finding interesting things in the solar system and beyond. Right ascension and declination will pinpoint the object of interest, as do latitude and longitude on a state map, but in actual conversation, it's easier to explain to someone, even for astronomers, that M31 (Messier object) is found in Andromeda than it is to give a precise sky position. In fact, some nebulae and galaxies are named for the constellation in which they're found -- M31 is better know as the Andromeda Galaxy.

When the ancient Egyptians and Greeks observed the night sky, it looked slightly different than it does now. The reason is that the stars aren't fixed in place -- they're on the move across the galaxy. Though some of the mere handful of stars that we can see in the Milky Way move in similar directions and velocities, unless each star in a given constellation travels in the same manner, over time, these stars will have a different configuration from our perspective. For example, by the end of the next millennium, the Little Dipper (part of Ursa Minor) probably won't resemble a dipper or ladle at all. It may look more like a broom. The brightest star in the Little Dipper, Polaris, is the star closest to the North Pole today, but 3,000 years ago another star hovered above the Pole, and 3,000 years from now, a different star will mark the "spot." In case you're feeling a bit betrayed by all this, not to worry, in just 26,000 more years, old Polaris will be back where it belongs.

The most prominent star in the eastern sky at this time of year is the orange-red Arcturus, in the constellation Bootes -- a kite-shaped star group. This beacon of the spring sky moves very peculiarly -- perpendicular to instead of parallel to the plane of the galaxy. It's motoring through space, in our direction, at about 5,000 miles per hour or so. It's now almost at its nearest point to us, but sadly, in a million years it will have faded from view, and it's orbit will never again approach our portion of the Milky Way. Within a few thousand years, Arcturus, though still very bright, will no longer be the focal star in Bootes.

If suddenly, the old slate of stars we're used to seeing were wiped clean and a new array appeared, we likely wouldn't be naming constellations after Greek Gods, dragons or navigational aids. The spring sky might be filled with groupings of stars that would include the Nerd -- the line of stars forming the "Pocket Protector" would be akin to "Orion's Belt" today. While the irritating cluster forming the Cell Phone would be tucked near where Polaris now resides -- remaining in view all night and all year long.

For more about this see Myths, Legends and Lore -- http://www.frostydrew.org/observatory/courses/myths/booklet.htm#Boot
and
Astronomy Facts -- http://www.pa.msu.edu/people/horvatin/Astronomy_Facts/astronomy_facts.htm

Also see Secrets of the Night Sky by Bob Berman

This week's question comes from Dr. James Foster. Dr. Foster originated this series and did it as a solo project for the GSFC website for EIGHT YEARS! This year Dr. Foster has decided to share the enthusiasm he has for this project with other Goddard scientists and will be posing questions on a semi-regular basis.