![]() On September 27, we’re going to have a perigee full moon-the closest full moon of the year.” “When the moon is farthest away it’s known as apogee, and when it’s closest it’s known as perigee. “Because the orbit of the moon is not a perfect circle, the moon is sometimes closer to the Earth than at other times during its orbit,” said Noah Petro, deputy project scientist for the Lunar Reconnaissance Orbiter at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The expected rate is fewer than one “Blood-Harvest-SuperMoon” per century, and in fact the upcoming event is the only one that will occur in the period 2000-2099.But what is this behemoth of the night sky? Not a bird, not a plane, it’s a supermoon! Although this incarnation of the moon comes around only once every year, it’s not as mysterious as you might think. However, the odds of all happening at once are remote. None of them is uncommon: in the 21 st Century there are 86 Total Lunar Eclipses, 89 (full) SuperMoons and 100 Harvest Moons. In each case, the lore surrounding the Blood Moon, the SuperMoon, or the Harvest Moon has a basis in science. The geometry of the Harvest Moon provides many consecutive days of favourable moonlit conditions in the evening hours for farmers harvesting their crops. It so happens that this month’s Full Moon is the “Harvest Moon”, the most famous of the named moons that cycle through the calendar each year.At such times the Moon also appears bigger than usual, and brighter – or would be if it wasn’t eclipsed! Such events happen routinely every 14 lunations (lunar months), and have real effects – for example there will be especially high and low tides at this month’s Full Moon. ![]() The Moon will be near its closest point to the Earth during the eclipse, the so-called “SuperMoon” or as we astronomers call it, the “perigean Full Moon”. ![]() Actual shading varies from one eclipse to the next due to different conditions within Earth’s atmosphere. Thus the fully eclipsed Moon – the so-called “Blood Moon” - generally appears red or ruddy. This is preferentially red light, for the same reasons that our sunrises or sunsets are primarily red. At such times it no longer reflects direct sunlight as Earth is in the way, however, our planet’s atmosphere acts as a lens that refracts sunlight forward. Often just a fraction of the Moon passes through Earth’s umbral shadow, but in a total eclipse the entire Moon is immersed in that primary shadow. If that moon is new, an eclipse of the Sun may occur if its full, it is the Moon itself which is eclipsed. But a couple of times per year our satellite will be passing through the Sun-Earth plane - the aptly-named “ecliptic” - just when it’s aligned with the two. Usually the Moon with its tilted orbit passes well above or below Earth’s shadow. Total eclipses occur less than once per year on average, despite there being a Full Moon every month. This month’s Full Moon is special for a few reasons: Observers specific to Edmonton and the Capital Region will need an unobstructed eastern horizon to see the opening act of the eclipse, but the Moon will continue rising into the southeastern sky throughout the evening hours. The eclipse can be observed from anywhere on the night side of Earth where clear skies prevail. ~22:45 Penumbral shading may be still be perceptible Here’s the full sequence of events as seen from Edmonton:ġ9:16 (7:16 pm) Moon rises due east, already partially eclipsed The Moon will be blocked from view by other campus buildings for the earlier portion of the event. The University of Alberta Observatory (5th Floor, CCIS Building) will also be open from 9:00 – 9:30 pm for students and public to observe the last part of totality. The Public Observatory at TELUS World of Science is open to everyone, free of charge. Weather conditions permitting, the facility will be open for its normal Sunday evening shift from 7-10 pm and through to the end of the partial phases. One place to view this event is at the Public Observatory at TELUS World of Science – Edmonton and the adjoining meadow in Coronation Park where additional private telescopes will be set up by members of Edmonton RASC, which also provides the lion’s share of volunteer interpreters inside the Observatory. In this case the “total” phase of the eclipse will last 72 minutes, from 8:11 to 9:23 pm MDT. A lunar eclipse is one of the most accessible astronomical events, visible to the naked eye, or through the lens of binoculars, telescope, or camera.Įach phase of a lunar eclipse can last an hour or so, since it takes the Moon roughly that long to move its own diameter against the sky totality can last somewhat longer due to the substantial size of Earth’s umbral shadow at the Moon’s distance. A significant astronomical event will take place during the evening hours this Sunday, September 27, when Edmonton skies will be graced by a total eclipse of the Moon.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |