Naming the cosmos
Posted February 2, 2012
When Neil Armstrong uttered those famous words "Houston, Tranquillity Base here. the Eagle has landed" his spacecraft was nearly out of fuel and the situation was anything but tranquil. So where did the name "tranquility" come from?
Apollo 11 setup its base of operations near the southwestern edge of the Sea of Tranquility, named by Italian astronomer Giovanni Battista Riccioli it in the 1600's. This dark smooth feature must have looked peaceful to him. In those days whoever discovered it and got word out, named it. Explorers name things. It's what they do.
Today, naming processes are much more formal. Discoveries come at a much faster pace. The official names used by the scientific community for stars, planets, moons, and features on them such as craters, hills and valleys are determined by the International Astronomical Union (IAU). This is the same organization which provided the technical definition of a "planet" and demoted Pluto in the process. But that's for a future blog.
With so many names to keep straight, themes have emerged.
Mountains on Mercury are named for the word "hot" in various languages. Features on Venus, itself named for the Roman goddess of beauty, are named for other goddesses. You'll find craters on Mars named for scientists known for their study of the red planet. Pragmatic JPL scientists have come up with some interesting nicknames for the rocks and other features the Mars rovers Spirit and Opportunity have encountered along the way including duck, Scooby Doo, and Route 66. A particularly hot Southern California summer seems to have led number of ice cream inspired names for soil textures on Mars including "Mudpie," "Coconut," "Cookies and Cream," and "Chocolate Chip."
As we move out to the featureless gas giants, their moons get all the interesting names. Features on Jupiter's moon Io, known for its volcanic activity, are named for fire gods and characters in Dante's Inferno. On Saturn's moon Titan, the only other body in our solar system where liquid abounds, names are drawn from Earthly lakes, rivers and seas. Moons of Uranus are dominated by Shakespearean characters and places, a favorite of discoverer William Herschel.
Neptune is named for the Roman god of the sea so the aquatic theme assigned to its lunar features makes sense.
The (former) planet Pluto was named for the Greek god of the underworld not the cartoon dog as many assume. It was actually the other way around as Disney Archivist Dave Smith confirmed, pointing to the screen debut of Pluto (the dog) months after the announcement of Clyde Tombaugh's discovery of Pluto (the planet) . The name was suggested by 11 year old Venetia Phair in 1930.
Closer to home, craters on our own moon are named for scientists and explorers. Tycho, the Danish astronomer, is remembered by a crater which dominates the southern polar region. Smaller craters around Apollo crater are named for fallen American astronauts. Russian Cosmonauts receive a similar honor around the Mare Moscoviense.
Names for the brightest stars are derived from their Arabic names (Betelgeuse, Vega, etc.). Other stars are known by the constellation they are in along with a greek letter corresponding to brightness within the constillation (Alpha Orionis, Alpha Lyrae). Dimmer stars and new discoveries are doomed to the more mundane catalog numbers (HIP 91262, HD 39801).
In coming weeks you might be tempted to purchase one of the star naming packages for your valentine. Be aware that your $50-$150 gets you a coordinates that may or may not make sense along with a certificate suitable for framing and not much else. These services carry no official authenticity, scientific or otherwise. The IAU doesn't recognize these services. Instead, consider a constellation book and an invitation for your sweetheart to spend an evening stargazing and come up with your own names.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.