Big rock
Question: Why does our Moon not have a name? Can we call it Eeyore?
Answer: Moons around other planets in our Solar System are named by the
International Astronomical Union. A working group on planetary nomenclature
decides on the names, which the IAU鈥檚 General Assembly must verify. The next
time this body meets will be in Sydney in 2003.
Themes have been established for naming celestial bodies and features on
them. For example, new moons of Uranus are named after characters in
Shakespeare鈥檚 plays, notably The Tempest. Caliban and Sycorax are among
the latest characters honoured. Craters on the asteroid Eros are given suitably
erotic names, such as Lolita. But there have been no plans to rename our moon,
the Moon.
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A different IAU body would be responsible for naming the planets that have
been discovered orbiting stars outside our Solar System.
Jay Pasachoff
Astronomy Department
Williams College
Massachusetts
Answer: Some years ago, a couple of Australian schoolgirls wrote to New
杏吧原创 (Letters, 9 February 1991) saying that they had discovered that
the Moon did not have a name and they had decided to name it 鈥淒ijon鈥� after
themselves. It seems that they were unsuccessful, and I can only assume that
they had limited their search to the scientific literature.
Of course the Moon has always had a name. It is just that no one uses it any
more except poets. The ancient Greeks and Romans named every heavenly body they
could see, and the planets of the Solar System were named after their gods and
goddesses which, of course, has given us Jupiter, Saturn, Mars, Venus, etc. The
Sun was called Apollo by the Greeks and Phoebus by the Romans, and the Moon was
known as Artemis to the Greeks and Diana or Luna to the Romans.
Lesley de Bruijn
Harare, Zimbabwe
Answer: The Earth鈥檚 Moon does have a name, Luna, which is the name the Romans
gave to their goddess of the Moon. From this we get the adjective 鈥渓unar鈥�, which
refers to properties of our Moon, as opposed to any other planet鈥檚 moon.
Because Luna is the only Moon which is visible with the naked eye, it can
also be referred to as 鈥渢he Moon鈥�, since it is clear which one is being talked
about. Our Sun is called Sol (again taken from the Romans), hence the adjective
鈥渟olar鈥�. If you refer to 鈥渢he Sun鈥�, most people will know which one you
mean.
Joel Smith
Pateley Bridge, North Yorkshire
Christmas cracker 2
Question: During Christmas tea, an argument began. How are the tiny edible
silver balls that are used to decorate cakes made and what produces the shiny,
silver colour? Some of us thought the coating was aluminium, but wouldn鈥檛 that
be a health hazard?
Answer: All sugar sweets of this type are made in the same way. Seed sugar
crystals are rolled in a sugar mixture inside a large rotating drum for several
days or weeks, depending on how thick the layer needs to be. This process
deposits a thin, uniform layer around the seed crystal which gradually builds
up, much like a pearl, to produce a solid spherical sugar core. The silver is
added to the mixture and coats the ball. As you correctly guessed, the coating
is aluminium.
Consumption of metal has been a delicacy in India for many years; a thin
layer of gold leaf is laid on top of several traditional puddings.
As for the dangers of consuming aluminium, there is no proven risk in eating
the small quantities you find in cake decorations.
Sam Ellenby
London
Answer: The balls found on decorated cakes are indeed coated with aluminium
(which has the European additive number E173) to make them silver in eating
colour, and glazing agent E903 (carnauba wax) is used to make them shiny. E174
(silver) can be used instead of aluminium.
Jackie Mather-Shone
Tyne and Wear
Answer: Perhaps more spectacular is the little-used practice of using E175 to
gild roast chicken. E175 is, of course, gold.
Simon Scarle
Brighton, East Sussex
This week鈥檚 question
Thin ice: I discovered ice helicites 鈥済rowing鈥� out of rocks
near Frome in Somerset. The temperature had hovered around freezing for several
days and the Sun had been unable to melt the ice formations because they were in
a steep, shaded valley. They were growing from the ground and rocks around an
old iron works. How did they form and why are they curled into different shapes?
Some were as thin as human hair and around 3 centimetres long.
Chris Martin
Bristol