Wednesday's sunrise will be a markedly
different one than usual, for as the golden disc rises about the horizon, it
will be scarred by a small black dot floating across its surface.
This is the planet Venus, which will stand out
in silhouette against the sun - taking a quick bow in the limelight. The next
time it takes to the stage, 105 years will have sailed by, meaning most people
alive today will not be around to see the encore performance in
2117.
The entire transit, lasting 6 hours and 40
minutes, will be visible almost worldwide - but if you are in the UK and don't
want to miss it, it will be an early rise
at 5.55am.
Beginning on Tuesday at 11.04pm BST, skywatchers
in the United States, Canada, Mexico, Central America, and the northern part of
South America will see the beginning of the show before the sun
sets.
Assuming the Great British Summer decides to
give us a clear morning, you will be able to view the transit from home - but
make sure you do it safely, with this advice from NASA:
Inexpensive eclipse shades have special safety
filters that appear similar to sunglasses, but these filters permits safe
viewing. However, with less than 48 hours to go, these may be tough to track
down in time.
If you have binoculars or telescopes, special
solar filters are available. However, never ever use a telescope without a
filter or look directly at the sun - or you will irreparably damage your
eyesight. And NASA warns not to buy solar filters that attach to the eye-piece,
as these are not always safe.
But if there is a telescope to hand, find a
screen and project the sun onto it. This will provide a magnified view of the
sun, and the clearest way of seeing the transit yourself - but find a safe
surface to project onto, as this can be a fire risk.
Pinhole projectors have the advantage of being
easy and inexpensive, although their view is unmagnified. For advice on how to
make one, check out the page at Stanford.
More advice is available at NASA's Transit
page.
[Via dailymail ]
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