The way that the Milky Way appears to us is not easy to determine not only because it is not always clear to see all along its length but also because during the course of a night its orientation across the sky changes dramatically. This nocturnal change is actually a diurnal change. We just cannot see the change happening during the daylight hours. This same change happens over the year if viewed at midnight on successive nights.
The way to begin to make sense of the movements is to understand how the Earth is orientated in the Milky Way. See the figures overleaf for full sky views showing the Milky Way as seen from the Southern hemisphere at midnight. In March the Milky Way stretches across our southern horizon; in June it arcs overhead from NE to SW; in late September (and particularly on 10th October) it rings the entire horizon and in late December it arcs from NW to SE.
The Earth in the Galaxy Model makes it possible to understand WHY these changes happen. The Earth is orbiting the Sun and moves from the side of the Sun closest to the center of the galaxy in June to the opposite side of the in December. This means that:-
at midnight on 21 June, viewers on Earth look towards the center of the galaxy.
at midnight on 21 December viewers look away from the galactic center.
The Earth is tilted by 60 degrees from the galactic axis and in a direction about 30 degrees from the tangent to the galactic disk. This orientation can be seen in the model. The result of this orientation is that around 21 June the center of the galaxy appears directly overhead at midnight for viewers at approximately 30 degrees south of the equator for instance in southern Africa.
Rotate the Earth ball so that Africa faces the galactic center and imagine that you are looking up at midnight in June at the Milky Way from your position on the southern African continent. See how the Milky Way arcs from the NE (China) to the SE (Chile). Rotate the Earth ball 180 degrees and see how in December the Milky Way arcs from NW (North America) to SE (southern Australia). Rotate the Earth ball so that Africa is on the upper side of the model and see how the galactic disk crosses over the southern horizon. Rotate the Earth ball so that Africa is on the lower side of the model and see how the galactic disk rings the entire horizon.
The Starwaders Galaxy Model can be purchased for R150.
Send an email to firstname.lastname@example.org with your contact and postal address details. State which models you are buying and the total price.
An EFT transfer can be made into the account details below. Add R30 for post and packaging. For cash deposits add another R15 to the price.
You are welcome to make arrangements to collect the model on a COD basis. Ask for address and directions in your email.