A minor planet has been named after a Bengaluru student. What are the rules behind such nomenclature?
Last week, Sahithi Pingali, an 18-year-old student at a Bengaluru school, received the rare honour of having a minor planet named after her—fewer than 15,000 people on Earth have one named after them. Pingali recently won top awards at the Intel Science and Engineering Fair (ISEF) for devising a way to deal with the froth-forming pollution that afflicts the lakes of the southern city. That is how the Lincoln Laboratory of the Massachusetts Institute of Technology (MIT) identified her to be included in its list of honorees for its Ceres Connection programme that it started in collaboration with the Society for and the Public. The Ceres Connection is an initiative that names minor planets that have been discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) programme after students through the fifth grade to the twelfth and their teachers for excellence in science and technology.
So, how are celestial bodies assigned their names? The ancient Romans have certainly left a cosmological imprint, with most of the names that we recognise today coming from their mythology (the Greeks play the second fiddle). After the formation of the International Astronomical Union (IAU) in 1919, the power to officially approve a name for a celestial body has rested with it—it oversees the christening of asteroids, planets, minor planets, comets, moons and geographical features on planets and moons. The nomenclature protocol starts with a sequence of processes to ensure that a particular celestial body hasn’t been already identified and named. This itself is likely to take months, given the rules specified, for instance, in case of minor planets, require between two to four “oppositions”—two celestial bodies are said to be in opposition when they are diametrically on the opposite sides of a third body (from out vantage point, the third body is the Earth). Upon confirmation of their status as new discoveries, the IAU grants them permanent numerical identities—it is only then that naming begins. While conventionally comets have been named after their first two discoverers’ surnames (sample Shoemaker Levy), the process for naming minor planets is rather elaborate.
The discoverer—in case of multiple claims, the IAU also has guidelines for settling this—has the privilege to then propose a name within ten years of the minor planet receiving the permanent number. The discoverer must submit her proposal along with a short citation on why a particular name is being proposed—the proposal is then examined by the 15-member Committee for Small-Body Nomenclature comprising astronomers with research interests in minor planets. There are rules here, too—the proposed name must be of 16 or fewer characters, preferably one word, non-offensive and not too similar to the name of an existing celestial object. Names of persons or events know primarily for their association with military events or politics are acceptable only after 100 years of their death or occurrence. Names of pets are discourage, and names of purely or principally commercial nature are not allowed. The minor planet’s name only becomes official after it has been published in IAU’s monthly Minor Planet Circulars. In the case of geographical features on planets and satellites?
Well, the IAU follows a system that it has developed over the years—the names are drawn from a wide pool, Greek, Roman and Celtic gods and heroes, abandoned cities (Mercury’s valleys Angkor Vallis, Caral Vallis, Timgad Vallis), etc. Exoplanets—that orbit a start outside our Solar System—discovered first as recently as 1992, till 2015, had named that were derived from the star they orbit. This year, after a 2015 online name-suggesting contest, IAU approved names for 17 exoplanets, including Thunder Bay and Brevardastro.
You may also like to watch this video
The pain point? Stars. Stars remain beyond the scope of IAU nomenclature—as as result, the same yellow dwarf star in the Ursa Major constellation is variously called 47 Ursae Majoris, FK5 1282, GC 15087, Gilese 407, HR 4277 and SAO 43557!