ScienceOnline is an interactive resource for students and teachers of science.
The site provides access to a range of activities related to the New Zealand science curriculum for Years 9-11. Both Astronomy and Earth Science have been included as well as the core science areas of Physics, Chemistry and Biology. There are interactive notes and diagrams, self-marking tests, and useful links to other science websites. The site is completely up to date with NCEA requirements at Year 11 with details of achievement standards linked to topics in each of the five subject areas.
ScienceOnline has been developed by Peter Biggs, former science teacher and author of the Blue Science Book, and Sandy McGivern, science teacher, who manages the site.
The Moon orbits the Earth which, in turn, orbits the Sun. These movements produce a number of effects as seen from the Earth such as the phases of the Moon, the tides of the sea and lunar and solar eclipses.
Sunlight falling on the Moon's surface is reflected onto the Earth. As the Moon revolves around the Earth we see different areas of the illuminated Moon which we call the phases of the Moon. Note that the Sun always shines on half the Moon - it's just that we cannot always see the illuminated side and the part we can see gives us the phases of the Moon. These are shown below.
ScienceOnline ::: The phases of the Moon
The First and Last Quarter
The phases First Quarter and Last Quarter are called this because they are 1/4 and 3/4 of the way through the lunar monthly cycle.
The waxing and waning of the Moon
The Moon is called waxing when it grows from a New Moon (dark) to the Full Moon (fully lit). The reverse is called waning when the Moon appears to fade from a Full Moon through to a New Moon.
The month and week
The Moon takes 29.53 days (29 days 12hr 43 min) to orbit the Earth. This period is a Moon cycle which we now call a month. Each quarter of the cycle takes about 7 days which we now call a week.
The Moon has a diameter of 3476 km compared to 12756 km for Earth. Its gravitational pull at the surface is 1/6th of the Earth. It orbits in an almost circular orbit of 384,000 km from the Earth. At this distance it took the Apollo spacecraft 3 days to reach the Moon.
The face of the Moon is cratered from meteorite bombardments and darkened by vast basalt-like lava flows. These make up the face of the 'Man in the Moon'.
The Moon spins on its axis as it revolves around the Earth so that it keeps the same side facing the Earth as it orbits. It was not until 1959 that photos were taken of the reverse side of the Moon by the Russian spacecraft Lunik III. The first Moon landing was in July 1969 when the US Apollo craft put the Eagle moon lander on the surface and Neil Armstrong stepped out. Moon rocks returned to earth for study.