First the moon will look orange – then it will turn red.
No, the moon is not running election ads. But on Sunday night, observers across Canada will have a chance to witness what promises to be one of the most colourful and photographed celestial events of the year: a rare total eclipse of a fall harvest "supermoon."
The harvest moon is the traditional name for the full moon that falls closest to the autumnal equinox. For observers in Eastern Canada, it will rise at sunset on Sept. 27, looking big and pumpkin-coloured, as it usually does at this time of year.
But starting at 8:11 p.m. Eastern Time, the moon will begin to darken as its eastern limb dips into Earth's shadow, marking the beginning of the lunar eclipse. The change – too subtle to notice at first – will be obvious once the edge of the moon reaches the umbra, the dark, central part of the shadow, about one hour later.
The eclipse becomes total at 10:11 Eastern or 7:11 Pacific, around the same time it rises for observers on the West Coast.
At that point, the moon should turn a deep copper colour, illuminated only by red-tinged sunlight that has been refracted through Earth's atmosphere. The amount of dust in the atmosphere will determine how dark the moon gets during the peak of the eclipse. For those watching far from city lights, the stars will become more visible as the moon dims.
The total eclipse will last 72 minutes, after which the moon will start to re-emerge from shadow, eventually returning to its normal look a couple of hours later.
The event has been dubbed a "supermoon" eclipse because the moon will also be near the point in its orbit that is closest to Earth. At such times, the full moon looks about 7 per cent larger than average.
Unlike eclipses of the sun, lunar eclipses can be observed and photographed safely without the need for protective filters. A pair of binoculars can improve the view and the result should be well worth watching, astronomers say. Canada won't see another total eclipse of the moon until January, 2018, and the world will have to wait until 2033 before the next supermoon eclipse.
Public viewings of the event are planned at a number of locations across Canada, including the Rio Tinto Alcan Planetarium in Montreal, the Ontario Science Centre in Toronto, the Telus World of Science in Edmonton and the HR Macmillan Space Centre in Vancouver. The eclipse will also be streamed live online by NASA TV.