Newsletter 7                           February 1999

The Bunny On The Moon

If you have ever observed the moon through binoculars or a telescope you will appreciate the excitement of actually looking at the surface of another world. Our natural satellite the moon is only 390 000 km away - so even with the naked eye one can easily make out numerous distinct features on its surface. Identifying these features is most enjoyable, and most of them carry exotic and romantic names.

THE "SEAS"
The first thing one notices when looking at the moon with the naked eye are the broad, dark plains known as "seas". These "seas" are actually huge, bone-dry impact craters which were filled with lava sometime during the moon’s ancient past. Four of the most prominent of these "seas" appear to form the shape of a stylized bunny (see diagram). Once you learn to spot the ‘bunny on the moon’, you will find it easier to add to your knowledge of the moon’s features.

MARE TRANQUILLITATIS
If you had to visit the Sea of Tranquillity (our bunny’s head) today, you would see a lonely flag flying on the barren landscape - planted there 30 years ago by the first humans to walk on the moon. Upon stepping out of the Apollo 11 module on 21 July 1969, Edwin Aldrin spontaneously described the scene before him as "Magnificent desolation".

The moon’s surface is rugged, desolate and pitted with craters; there is almost no colour, and certainly there is no life. Nothing moves, nothing breathes, nothing stirs. Unlike our lovely home planet Earth, the moon has been sterile throughout its long history.

SAME OLD FACE
The moon, like most large objects in space, spins slowly on its axis. It takes 27a days to complete one turn - and this is the same time it takes to make a full revolution of the earth. This means that it keeps the same face turned towards us all the time. Therefore, as long as the sun is shining on it, our ‘bunny on the moon’ is always there for us to see.

PHOTOGRAPHING THE MOON
A most enjoyable pursuit is photographing the moon through a telescope and then identifying the craters using a moon atlas. It is really exciting when you begin to match the craters and discover their names. Once you have seen the craters close-up and have come to know their distinct shapes, that region of the moon suddenly becomes a real place, a locality - somewhere you could perhaps visit one day....

Members of the Astronomy Interest Group have found that even with a small telescope, one can take amazingly clear photos of the moon using a digital camera.

Once we acquire a CCD video camera (which we are saving hard to buy), it will be possible to view close-up video footage of the moon as seen through our telescope. An example of what such an image looks like can be seen on the AIG home page at:

Also, on the AIG Web site you will find fun photos of our recent field trip to Bushman’s Nek, all the AIG newsletters to date and a few other astronomy goodies.

 Mario Di Maggio

AIG Event Horizon
All enquiries: Mario Di Maggio
Tel: 3006228 (w) or 082 829 7645
Enquiries about viewing evenings at Marist Brothers:
Raymond Field Tel: 3094126 (w) or 4657188 (h)