Naming the Asteroids

I wrote earlier about 3200 Phaethon, the asteroid that causes us to see the Geminid meteor showers that appear in December. The first asteroids to be discovered were named for characters from classical mythology, such as Ceres and Juno. But the International Astronomical Union (IAU) now regulates the naming of asteroids, and names are no longer restricted to only mythological characters.

The naming of heavenly bodies and celestial objects is quite interesting. An article from the Open University, says that an asteroid is not awarded a name until it has been observed long enough for its orbit to be determined with a fair degree of precision, which may take several years.

The “permanent designation” is a rather boring number issued in strict numerical sequence, but the discoverer is invited to suggest a name for approval by a special committee of the International Astronomical Union.

As we begin to be able to land on these asteroids, the idea of mining asteroids becomes less science-fiction and more like an actual space industry.

There are some much more unusual or whimsical names.

7758 Poulanderson is named after a science fiction author Poul Anderson.

I quite like that object 8749 is named "Beatles" after best known of all rock bands. In addition to 8749 Beatles, there are four consecutively numbered minor planets named after the individual members of The Beatles:

• 4147 Lennon (John Lennon)
• 4148 McCartney (Paul McCartney)
• 4149 Harrison (George Harrison)
• 4150 Starr (Ringo Starr)

The Beatles are not alone in being pop musicians with celestial objects bearing their names. Elvis, Frank Zappa, Jerry Garcia, the Rolling Stones (which seems appropriate for these rocks), Frank Sinatra, George Gershwin, Led Zeppelin, Procol Harum, Bruce Springsteen and many others are all floating out there.

And fictional names also get their place in space. From Beowulf to Bilbo Baggins, Sherlock Holmes and Mr. Spock.

The number 5460 asteroid has the name Tsenaat'a'i which means “flying rock” in the Navaho language.

A name of pure invention, and some difficulty to pronounce at first glance, went to object 2037. It is named Tripaxeptalis. It is pronounced to sound like tri Pax sept Alice. The etymology of that is that its permanent designation is three times (tri) that of asteroid 679 Pax and seven times (sept) that of number 291 Alice.

 

Naming the Comets

Time-lapse of Comet 2I Borisov

An artist’s impression of `Oumuamua as a dark red highly-elongated metallic or rocky object,
about 400 meters long, and unlike anything normally found in the Solar System.

On December 8 this year, a newly discovered comet looped around our Sun after a journey of more than 100 million years from the birth of some very distant star. It makes its closest pass to Earth today and then heads out of our solar system again. By the middle of 2020, the comet will streak past Jupiter's distance of 500 million miles on its way back into interstellar space where it will drift for untold millions of years before skirting close to another star system.

It's only the second interstellar object to visit us, so it's a big deal. But it has the very boring name of "Comet 2I Borisov." It was discovered by Gennady Borisov, a Crimean astronomer, and, of course, he wanted his piece of history.

A much more interesting name goes to the first interstellar object to visit our solar system. That was ʻOumuamua.

The International Astronomical Union assigns designations for astronomical objects and they originally classified it as Comet C/2017 U1. Then it was reclassified as the equally boring asteroid A/2017 U1. The renaming was because it had no "coma" - the nebulous envelope around the nucleus of a comet formed when the comet passes close to the Sun and warms so that it gets a "fuzzy" appearance when viewed in telescopes and distinguishes it from stars. The word coma comes from the Greek "kome" (κόμη), which means "hair" and is the origin of the word comet itself.

Once this comet was identified as coming from outside the Solar System, a new designation was created: I, for Interstellar object. ʻOumuamua, as the first object so identified, was designated 1I but is also referred to as 1I; 1I/2017 U1; 1I/ʻOumuamua; or 1I/2017 U1 (ʻOumuamua). I'm only interested in ʻOumuamua.

What caught my attention first was that first character which is a Hawaiian ʻokina, and not an apostrophe. It is pronounced as a glottal stop.  The name comes directly from the Hawaiian word ʻoumuamua, meaning "scout," because the object has come from so far away to check us out. The name was chosen by the Pan-STARRS team in consultation with Kaʻiu Kimura and Larry Kimura of the University of Hawai‘i at Hilo. It was discovered by Robert Weryk using the Pan-STARRS telescope at Haleakala Observatory, Hawaii.

That is a much better name than 1I. But I would have been quite happy if they had gone with another suggested name: Rama. That is the name given to an alien spacecraft discovered under similar circumstances in the 1973 science fiction novel Rendezvous with Rama by Arthur C. Clarke. It's a novel I really enjoyed reading. That object was seen as an alien craft that was on a scouting expedition checking out the rest of the universe.

 ʻOumuamua is tumbling, rather than smoothly rotating, and is moving so fast relative to the Sun that there is no chance it originated in the Solar System and it cannot be captured into a solar orbit. It will leave our Solar System and resume traveling through interstellar after roughly 20,000 years of travel in the Solar System.

ʻOumuamua's planetary system of origin and the amount of time it has spent traveling amongst the stars are unknown. I love that mystery.

Ultima Thule

It is more difficult to get the public interested in celestial objects when they have names like "2014 MU69." Astronomers tend to name things initially and officially in that way but "sexier" names seem to come later more and more. (see this about that) This is a good thing. This site asks, "What's in a name?" A character from Shakespeare might say it doesn't matter, but I say it matters a lot.

The NASA team that works with the New Horizons exploratory spacecraft gave 2014 MU69 the nickname of Ultima Thule. Much better.

Thule was a mythical island that appeared on some old maps as being at the edge of the known world. It was also labeled as "Tile" on at least one map from 1539 called the Carta Marina. This was a map of what Nordic sailors knew about the world. They placed Thule near the Faroe Islands.

The Faroe Islands are not mythical. They (AKA Faeroe Islands) are a North Atlantic archipelago located 200 miles (320 km) north-northwest of the United Kingdom and about halfway between Norway and Iceland. Today they are an autonomous country of the Kingdom of Denmark with a total area of about 540 square miles and a population of over 50,000.

The direct translation of Ultima Thule is “beyond Thule” and is a very fitting name for something beyond the edges of our currently known world.

If you want to know a bit more about the space exploration side of Ultima Thule, check out this post on one of my other blogs. 

Thule (TILE) near the Faroe Islands - Carta Marina map, 1539.

3200 Phaethon

The Fall of Phaëthon on a Roman sarcophagus
 (Hermitage Museum - Wikimedia)

This week will have the best nights for watching the Geminid meteor showers which appear to come from the constellation Gemini, but these showers are caused by the celestial object 3200 Phaethon, which is an asteroid.

That is unusual and this is one of the only major meteor showers not originating from a comet. This asteroid has an orbit that brings it closer to the Sun than any other named asteroid. And that association with the Sun is how the asteroid got its name.

The first asteroids to be discovered were named for characters from classical mythology, but names are no longer restricted strictly to mythological characters.

Phaethon was the Ancient Greek name for the planet Jupiter, a planet whose motions and cycles were observed by the ancients and often used in poetry and myth.

In mythology, Phaethon's father was the sun god Helios who granted his son's wish to drive the sun chariot for a day.  Phaethon was unable to control the horses. To prevent the chariot from hitting and destroying Earth, Zeus knocked it out of the sky with a thunderbolt. Phaethon fell to earth and was killed.

These radar images of near-Earth asteroid 3200 Phaethon were generated by astronomers at the National Science Foundation's Arecibo Observatory on Dec. 17, 2017. Observations of Phaethon were conducted from Dec.15 through 19, 2017, at the time of its closest approaching December 16 when it was about 6.4 million miles or 10.3 million kilometers away, or about 27 times the distance from Earth to the moon. The encounter is the closest the asteroid will come to Earth until 2093.

Source: https://photojournal.jpl.nasa.gov/catalog/PIA22185