January 17, 2003

**SOLAR SYSTEM NOMENCLATURE**

**A TRIBUTE TO MERTON E. DAVIES**

Tobias Owen

Institute for Astronomy

University of Hawaii

2680 Woodlawn Drive

Honolulu, HI 96822

owen@ifa.hawaii.edu

Solar system nomenclature as defined by the International Astronomical
Union (IAU) consists of the names of newly discovered objects and names
assigned to surface features on planets, satellites, asteroids and
comets. The naming of asteroids themselves is carried out separately.

The IAU was founded in 1919, and its nomenclature work was carried out
initially under the oversight of Commission 16: Physical Studies of
Planets and Satellites. This work was originally restricted to assigning
names to features on the lunar surface and standardizing lunar maps.
With the dawn of space exploration in the 1960's, it became necessary to
revise and extend nomenclature on the surface of Mars and an ad hoc
committee was developed to do this.

The Lunar Orbiter and Apollo Programs of the United States led to the
casual, unilateral assignment of names to features on the lunar surface
by astronauts and others, which angered the Soviets, who also had a
lunar program. Matters came to a head at a meeting of the IAU in Sydney,
Australia in 1973. There the Soviets requested the right to name
features on the far side of the moon, as they had obtained the first
photograph of this hitherto unseen hemisphere in 1959 (Figure 1). Crude
as this picture was, it revealed the most striking aspect of the lunar
farside, the near-absence of Maria. But there was one small Mare, and
the Soviets proposed to name it the sea of Moscow.

This caused considerable consternation among the other scientists
present at the meeting, since the IAU-endorsed tradition for naming
Maria on the near side of the moon relied mainly on names of various
hydrological phenonena (Mare Imbrium, the Sea of Rains; Oceanus
Procellarum, the Ocean of Storms; Palus Putredinus, the Marsh of
Corruption; etc.) or else states of mind (Mare Serenetatis, the sea of
serenity; Mare Tranquilitatis, the Sea of Tranquility, etc.). The
Soviets were adamant. Clearly some of their frustration at being
excluded from previous nomenclature decisions as well as some national
pride was in the air. In a beautiful piece of French diplomacy, Audouion
Dollfus, the contemporary president of Commission 16, used his authority
to rule that Moscow was in fact a state of mind! Thus we have the Sea of
Moscow comfortably established on the lunar far side.

This exercise reinforced a formal request from the Soviet Academy of
Sciences to the IAU at the Sydney meeting to open up the nomenclature
activity to international participation and review. Accordingly, the IAU
established the "Working Group for Planetary and Satellite Nomenclature"
(WGPSN) which has handled these matters ever since.

The first president of the WGPSN was the Canadian astronomer Peter
Millman (1973-1981), followed by the American geologist Hal Masursky
(1982-1990), followed in turn by the Norwegian astronomer Kaare Aksnes
(1991-present) who is the current president.

The WGPSN is organized into several Task Groups, each of which has a
chair and several members, all drawn from the international community of
scientists. The current chairs of these Task Groups are listed in Figure
2. The current membership of the WGPSN is given in Figure 3. In addition
to the President and the Task Group Chairs, the WGPSN always includes
the President of Commission 16 and the President of Division III of the
IAU, as this Division includes the solar system activities. There are
presently three consultants, of whom I would like to single out Jennifer
Blue for special mention. Ms. Blue is at the USGS in Flagstaff, Arizona
and is the *sine que non* of the WGPSN. She assembles and dispatches all
inquiries and requests for nomenclature and has developed and now
maintains the on-line Gazetteer that catalogues all the approved names.

Mert Davies was a highly active member of the Outer Solar System Task
Group and was Chair of the Mercury Task Group for some years. In fact,
he played a major role in all of the nomenclature activity during the
most intense period of this work, from 1973 -- 1993, when names were
required for the Viking, Voyager, and Magellan discoveries. Although the
WGPSN is divided into discrete Task Groups, in practice several of these
groups often met together so everyone was aware of what everyone else
was proposing. Mert was strongly involved in all of these discussions,
his graciousness and good humor repeatedly coming into play during
emotional confrontations. It is hard to imagine this massive effort
taking place without his creative and steadying influence.

One of Mert's many important roles in this activity was his strong and
steadfast support of international participation. This was particularly
critical in the case of the Soviet scientists. We were deep into the
Cold War and it was very difficult for them to attend meetings outside
their country. As a result, we frequently went to the USSR, and Mert was
always game to make these long trips. He often brought along his wife
Louise, whose kindness, patience, and unflagging good humor were much
appreciated. The two of them hosted Russian scientists visiting the US,
again breaking the political barriers that were making our work
difficult.

Mert supported the idea of including some discussions of scientific
results, which became a standard part of these meetings. Thus all
participants could present some short reports on their own research and
scientists from the host institutions (or others nearby) who were not
involved in the WGPSN and its primary function were invited to
participate. Thus "nomenclature" became an important pathway for
scientific exchanges.

In the end, all this good will and hard work had the desired effect. The
WGPSN assigned roughly 5000 names, with full participation from Soviet
(now Russian, Kazakh etc.) and European scientists.

The work is continuing, with new names required from the Galileo Mission
studies of Jupiter's satellites, ongoing Mars exploration, and the
anticipation of many new images of Saturn's satellites from the
Cassini-Huygens mission. The latter can serve as an example of how the
nomenclature activity proceeds.

Names for newly discovered satellites are chosen to conform to
established traditions. Discovers are encouraged to select names from a
name bank that is established according to this general guideline. In
the case of Saturn, the tradition is to use the names of Titans and
Giants from Greek mythology, the beings that the Olympian Gods had
defeated before becoming the accepted deities of the classical Greeks.
Names of surface features are selected from categories that are chosen
to be distinctly different for each object, preferably with some
association to the object itself (Figure 4). Thus Mimas, discovered by
William Herschel in England, was given the category of King Arthur and
Knights of the Round Table, a British legend. Enceladus was also
discovered by Herschel, but its surface is so strange and mysterious
that it was given the Arabian Nights as a name bank, linking a fantasy
landscape with a literary fantasy.

These assignments are suggested and discussed by the Task Groups,
presented to the WGPSN for further discussion and possible revision and
then submitted to the General Assembly of the IAU, which has final
approval authority.

An anecdote from one of our meetings may provide some of the flavor of
this activity. Figure 5 shows a gathering of members and guests of the
WGPSN session that took place in Montreal, Canada at the IAU meeting
there in August, 1979. Starting from the upper left the members present
were *Back Row*: A. Brahic, A. Dollfus, K. Aksnes, T. Owen, D. Morrison
(behind), B. Smith, E. Docheva. *Middle Row:* H. Holt, K. Runcorn, H.
Masursky, D. Campbell, S. Miyamoto, **M. Davies**. *First* *Row:* E.
Whitaker, G. Pettengill, W. Brunk. It is worth noting that the Soviet
delegation was not allowed by their government to attend this particular
meeting, despite considerable work by Peter Millman who had managed to
arrange for their housing and per diem. Shifting political winds and
reaction to current events sometimes thwarted our best efforts to break
through the icy barricades of the cold war.

One of the main topics of this meeting was the establishment of
guidelines for naming features on the surface of Venus. The group was
divided between those led by Brad Smith who wanted **all** the names of
Venus to be feminine, reflecting the fact that this is our only female
planet, and the rest of us, including Mert, who wanted to preserve the
names originally assigned to a few unusually radar-bright features first
discovered by ground-based observers using the powerful radars at
Arecibo and Goldstone. Brad Smith was particularly unwilling to
compromise, and we were stuck. At that point, as in a chapter from
Homer's Odyssey, Aphrodite herself intervened, disguised as an
attractive Canadian reporter who invited Brad for an interview. He left
the room with her and never returned! We decided that was a clear
message from Mt. Olympus, and that is why the map of Venus today
continues to preserve the original names of the brightest features first
distinguished by observers from Earth (Figure 6).

It should be evident from this brief review that the work on
nomenclature has its rewarding moments, despite the tedium of sorting
through all those names. What makes any enterprise like this worthwhile
is the character of the people who do it. Mert Davies was one of the
best. We all loved him and we all miss him. He cannot be replaced.

FIGURE LIST

Figure 1. The lunar Far Side, first photographed by Luna 3 in 1959. The
Sea of Moscow is Feature number 1. A slice of the hemisphere we see from
Earth is visible to the left of the dashed line.

Figure 2. Task Groups of the WGPSN. Chairs as of 1 January 03.

Figure 3. WGPSN Current Membership (1 January 03).

Figure 4. Major Satellites of Saturn: Names and surface nomenclature.

Figure 5. Attendees at the IAU nomenclature meeting in Montreal, Canada,
August 1979.

Figure 6. A map of Venus, based on Pioneer Venus Results.

TCO:dst1/17/03

Figure 1. The lunar Far Side, first photographed by Luna 3 in 1959. The
Sea of Moscow is Feature number 1. A slice of the hemisphere we see from
Earth is visible to the left of the dashed line.

![](media/image1.jpeg){width="5.999305555555556in" height="6.2875in"}

Figure 2. Task Groups of the WGPSN. Chairs as of 1 January 03.

## WGPSN

# **TASK GROUPS**

### Mercury

**M. S. Robinson**

**Venus**

**G. A. Burba**

**Moon**

**V. Shevchenko**

**Mars**

**B. A. Smith**

**Outer Solar System**

**T. C. Owen**

**Small Bodies**

###  B. G. Marsden 

Figure 3. WGPSN Current Membership (1 January 03).

#### **WGPSN**

# **MEMBERSHIP**

**President + Task Group Chairs**

**Comm. 16 Pres.: D. P. Cruikshank**

**Division III Pres.: M. Ya Marov**

**Consultants:**

**L. Gaddis (USGS)**

**P. Masson (European Space Agency)**

**J. Blue (USGS-Main Mover)**

**GAZETTEER**

[**http://planetarynames.wr. usgs.gov/**]()

Figure 4. Major Satellites of Saturn: Names and surface nomenclature.

*Satellites of Saturn*

***[Janus]{.underline}* People from myth of Castor and Pollux (twins)**

***[Epimetheus]{.underline}* People from myth of Castor and Pollux
(twins)**

***[Mimas]{.underline}* People and places from Malory's Le Morte
D'Arthur Legends (Baines translation)**

***[Enceladus]{.underline}* People and places from Burton's Arabian
Nights**

***[Tethys]{.underline}* People and places from Homer's Odyssey**

***[Dione]{.underline}* People and places from Virgil's Aeneid**

***[Rhea]{.underline}* People and places from creation myths**

***[Titan]{.underline}* Enchanted places, worldwide lakes**

***[Hyperion]{.underline}* Sun and Moon deities**

***[Iapetus]{.underline}* People and places from Sayers' translation of
Chanson de Roland**

***[Phoebe]{.underline}* People associated with Phoebe, islands of the
Greek archipelagos.**

Figure 5. Attendees at the IAU nomenclature meeting in Montreal, Canada,
August 1979. \[Some image defects are present from the original scan of
this image.\]

![](media/image2.jpeg){width="5.995833333333334in"
height="4.438194444444444in"}

Figure 6. A map of Venus, based on Pioneer Venus Results.

![](media/image3.jpeg){width="5.999305555555556in"
height="3.4472222222222224in"}