Introduction The asteroids are chunks of rock and metal which circle the Sun. It is estimated that there are hundreds of thousands of asteroids in the Solar System, most of them measuring only a few metres across, and most of them (around 95%) situated between the orbits of Mars and Jupiter, in an area known as the Asteroid Belt.
Astronomers had long been puzzled by the absence of a planet which should, by geometric law, be placed between Mars and Jupiter. In 1801, the Sicilian astronomer Guiseppe Piazzi discovered the first asteroid, Ceres, whose orbit corresponded to that expected from the “missing planet”. Soon after, many more asteroids were discovered through painstaking observation, and as photographic techniques were developed, astronomers pored over thousands of plates to find tiny specks of light moving across the background of stars – the tell-tale path of an asteroid.
Ceres is by far the largest asteroid, measuring around 1,000km across, or approximately the distance between Melbourne and Newcastle. The next largest asteroid, Vesta, is half this size, and only 20 are larger than 250km. Most that have been found are around the size of a house or a car. With asteroids, the rule is quantity rather than size, and Ceres alone accounts for one third of the mass of all known asteroids.
The Asteroid Belt covers a very large space, measuring between 2 and 4 times the distance between the Earth and the Sun, and most of the asteroids are situated tens of millions of kilometres apart, which explains why NASA spacecraft such as Pioneer, Voyager and Cassini experienced very little danger of collision during their trips to the outer planets. But some asteroids inhabit different orbits; a significant number are closer towards the Sun and cross Earth’s orbit, such as the asteroids Icarus and Apollo, while others are much further out beyond the orbit of Pluto, in an area known as the Kuiper Belt.
Through direct observation in various parts of the electromagnetic spectrum, astronomers have learned much about the colour, texture, warmth, physical make-up and spin of the asteroids. A number of spacecraft have visited asteroids and have made many valuable discoveries, and it is conceivable that in the future people might exploit the asteroids for mineral resources, an endeavour which will probably be accompanied by the kinds of conflicts and disputes which constantly seem to vex the human race.
I find asteroids fascinating. They are as much a part of the Solar System as the Sun, the Moon and the planets, and they are many; but for most of us they are largely unseen and unknown. I am not a scientist and The Asteroid Project is not a work of science. It can best be described as a verbal and visual contemplation, and an attempt to share my own sense of wonder upon a different order of reality – the realm of the asteroids.
FIRST FRAGMENT Litany I. Litany
Over the following five pages is a fabulous litany of the asteroids.
It is estimated that there are around 500,000 asteroids in the Solar System; of these, around 20,000 have been discovered and catalogued since Ceres was discovered by Piazzi on January 1st 1801. Due to advances in observational technology, most of the known asteroids have been found over the last 25 years.
I decided to focus my attention on the 2118 asteroids which had been catalogued up to 1979, the osculating orbital elements of which were tabled in Asteroids (edited by T. Gehrels, 1979) and derived from the Tuscon Revised Index of Asteroid Data (TRIAD). I was fascinated by the variety, the sounds and the richness of this list. Behind each asteroid was a human being who had discovered it, spending hours upon hours studying photographic plates and searching for the “blink” which indicates a moving object within a predicted field of space. In this spirit of effort, I decided to type out all 2118 names of the asteroids and present them as an unbroken list of words. No scanning, no photocopying, no pasting from websites: instead, the enjoyable application of time and concentration which, whilst merely an act of copying, was all about the love of text, the beauty of words and imagination. If I were a visual artist I would scatter these names all around an art gallery.
You will notice that some of the asteroids are listed as “Lost”. These sad objects had been discovered and verified by reputable astronomers, but they have never been seen again. Could these be ghost asteroids?
As you progress through the litany, you will see the names slowly change from female mythological characters to male astronomer-discoverers to dry catalogue numbers. I will explore names further in the Third Fragment; for now, it is time to meet a representative sample of the thousands and thousands of ancient asteroids which turn silently around the Sun, unnoticed and unknown by you and I.
There’s no escaping the need for human beings to name the things they find. Everything, it seems, that can be named should be named. So too with the asteroids, and although today it might seem an inward-looking and purely esoteric exercise to catalogue the minor planets, in future years it may well be appreciated as a wholly practical groundworking endeavour. Asteroids may well be unknown and unnoticed by most of us now, but one day, if people decide to start moving out through the Solar System, they will need to know how to avoid the traffic.
Biologists classify insects by species; astronomers classify objects by name. Astronomers acknowledge that each asteroid has its own orbital path, its own inclination, rotational period, colour, texture and shape. When an asteroid has been discovered, it gets a preliminary designation which is made up of the year of discovery followed by two letters, the first indicating the half month of observation (excepting the letters I and Z), and the second being the order of discovery within that half month. When all two-letter combinations have been used, numbers are added. So, for example, asteroid 1929CZ was discovered in the first half of February 1929, and was the 24th object discovered during that half month.
A permanent number is assigned the asteroid if and when it is found again and confirmed by someone else who is using the discoverer’s original measurements. After this, the discoverer may name the asteroid. Asteroids are referred to by both permanent number and name, such as 130 Elektra. At first, the custom was to name the asteroids after feminine mythological and literary characters; hence we have, for example,
This noble and gentlemanly method was quite successful until it became apparent that there were more asteroids than mythological characters. An effort was then made to introduce place names and male names in feminine form; hence we have
Next, the feminine form was gradually dropped and asteroids began to be named after scientists and, quite often, after the very blokes who discovered them:
And now, as bewailed by Gehrels (who, incidentally, had asteroid 1777 named after him in 1960), “the naming of asteroids has become messy because names suggested in the past by discoverers to recognize pets, friends and political heroes have been accepted” (1979, p. 14). And so we have
The list of named asteroids can and should replace baby name books. Imagine a world with people named Adzhimushkaj (1903) or Nocturna (1298) or Tezcatlipoca (1980). But amongst the asteroids you can also find familiar names. I found my maternal grandmother, my mother and both my sisters:
I also found my mother-in-law, my wife and her sister:
And up there amongst the asteroids is a name for many people to claim: 1203 Nanna.
Orbiting the Sun is an enormous resource of character and place names for novels or films. Imagine a story set in southern Arabis, where our main characters Wrubel and Arenda are enjoying lunch at the Giacobini trattoria. Suddenly,
Fanatica burst through the doors wielding a broken coffee cup.
Xosa the waiter was alarmed. He sprinted towards the kitchen. “Nordenmarkia! Aunus!” he yelled, “forget about the Bok salad, I need help!”
Wrubel turned pale. “Fanatica?” he whispered, weakly.
“You unconscionable turd,” growled Fanatica, staring darkly at Wrubel. “I knew I’d find you here. I’ve driven all the way from Delportia and what do I find?” She slowly raised an accusatory finger and pointed at Arenda.
Just then, Aunus raced into the dining room from the kitchen, armed with a cleaver.
And for astronomers with the need to pay homage to their heroes, asteroids can be awarded a special name. Six of my foreign idols in the realms of science and the arts have been honoured in this way:
2669 Shostakovich Dmitri Shostakovich, Russian composer
1906 – 1975
5020 Asimov Isaac Asimov, U.S. science and science fiction writer
1920 – 1992
3834 Zappafrank Frank Zappa, U.S. composer & musician
1940 – 1993
2709 Sagan Carl Sagan, U.S. astronomer and science writer 1934 – 1996
10221 Kubrick Stanley Kubrick, U.S. filmmaker
1928 - 1999
4149 Harrison George Harrison, U.K. composer & musician
1942 - 2001
All these names are far more attractive than the preliminary designations such as 1972RJ258AA and 1976HA53GZ. To give an asteroid a name is to acknowledge its unique physical identity and its existence as a real object which joins the Earth and the planets in orbit around the Sun. For astronomers it is a way of labelling a discovery and satisfying the whim to be a namer of things, just as it is satisfying to name pet fish and leisure boats.
But once they have been named . . . what then?
FOURTH FRAGMENT An Asteroid Belt
FIFTH FRAGMENT Happy Snaps
Now that your interest and appetite has been aroused, you’re probably wondering what some of the asteroids look like. Luckily, spacecraft from NASA and the European Space Agency have flown past a number of asteroids, giving beautiful pictures which excite the imagination. All photos are from NASA.
Ida & Dactyl
Asteroid 243 Ida was photographed by NASA’s Galileo spacecraft in 1993. Astronomers were thrilled to find that Ida has a tiny satellite – named Dactyl – which is the tiny object at right. The photo was taken from a distance of 10,000km. Ida measures 56km long, and they think Dactyl is around 1.5km wide.
At right is asteroid 433 Eros, shadowed strangely due to its irregular shape. In February 2001 the Near Earth Asteroid Rendezvous spacecraft (NEAR) touched down on the surface of Eros, giving astronomers and geologists plenty of work to get on with.
Here are several images of 216 Kleopatra, an asteroid shaped remarkably like a dog’s bone. These are radar and computer generated images from the Arecibo Radio Telescope, taken when Kleopatra was 171 million km away.
Asteroid 2669 Shostakovich lies squarely within the Asteroid Belt between Mars and Jupiter. NASA’s Near Earth Object Program keeps track of most of the known asteroids, and on their website you can enter the name of an asteroid and see its orbit and current whereabouts. On June 6th, Shostakovich was at the opposite side of the Sun in relation to Earth, and was 3.131 Astronomical Units (AU) away – or 470 million kilometres away.
What is Sedna? This planetoid made the news earlier this year. It’s not really an asteroid because it’s too big (estimated to measure 1700km in diameter) and it’s far, far beyond Pluto and the realm of the asteroids, currently being a preposterous 13 billion km away. The Hubble Space Telescope took this image of Sedna, which astronomers think may be part of the Oort Cloud, a ludicrously distant mass of objects which form a spherical envelope around the Solar System. They say the Oort Cloud extends halfway to the nearest star.
Afterthought In popular culture, asteroids and comets have often been depicted as randomly travelling, blindly evil objects which conveniently appear from on high to threaten the human race. There is a theory that an asteroid or comet collided with the Earth a few hundred million years ago and made the dinosaurs extinct. No wonder Hollywood has produced movies such as When Worlds Collide, Deep Impact, Armageddon and Starship Troopers, all which deal with cosmic collisions.
Asteroids and their brethren have been seen as another kind of natural disaster - pitiless and indiscriminate, like earthquakes or floods. The intrigue of asteroids is that they come from without, not within. The difference is: When an asteroid threatens Earth, we’re all stuffed.
Is there any actual risk of a future collision which could wipe us out? Perhaps comets are more risky; their orbits are more erratic than those of asteroids, and as smaller bodies they are more succeptible to gravitational perturbations from the Sun and planets. As far as asteroids are concerned, there are a number which cross Earth’s orbit, but over time there has been a kind of gravitational levelling which means that Earth will most likely avoid being hit. In any case, NASA’s Near Earth Object Program is constantly monitoring the asteroids, and hopefully we’ll be given plenty of warning if an asteroid is coming too close. All those movies will be sure to give us handy hints on how to survive. I particularly like the “space ark” concept behind When Worlds Collide. All we will need is a modern Noah to lead the way.
I prefer a more benign view of asteroids. They’re up there, over our heads in a million pieces, slowly spinning and warming themselves in sunlight. Huge potatoes, cratered stones, slender chunks. Specks of light, stellar in appearance, but moving steadily across the background of night. A rich field of splendid discovery; a taxonomic delight; a paradise for avid namers. Fragmentary leftovers of a constructed Solar System, they are a joyful abundance of stuff, things and palpable places, keeping us company in our tiny corner of the Universe.
These are the asteroids.
Sources & Further Reading
Audouze, Jean & Israel, Guy. (1985). The Cambridge Atlas of Astronomy. Cambridge University Press.
Garlick, Mark A. (2002). The Story of the Solar System. Cambridge University Press.
Gehrels, Tom (ed.) (1979). Asteroids. Tuscon: University of Arizona Press.
Harvard University Minor Planet Listing: http://cfa-www.harvard.edu/iau/lists/MPNames.html NASA Asteroid Webpage: http://nssdc.gsfc.nasa.gov/planetary/planets/asteroidpage.html NASA Jet Propulsion Laboratory Webpage: http://www.jpl.nasa.gov/ NASA Near Earth Object Program Webpage: http://neo.jpl.nasa.gov/ Near Earth Asteroid Rendezvous Mission website: http://near.jhuapl.edu/ Von Braun, Wernher & Ordway, Frederick I. (1979). New Worlds: Discoveries from Our Solar System. New York: Doubleday.
Whittingham, Richard. (1971). Astronomy. Northbrook, Illinois: Hubbard Press.
Here is an excerpt from the TRIAD asteroid listing, showing asteroid number, name and osculating orbital elements. This was my source for the Litany.
Scanned from Gehrels (1979).
Here is the first draft of the poem which appears as the Second Fragment. I wrote this during a few spare minutes I had on teaching rounds at Ringwood North Primary.