"Space Monday," as astronomers have dubbed it, kicks off in the late afternoon when SpaceX, the private spaceflight company, is planning a rocket launch. The Falcon 9, carrying its Dragon spacecraft to the International Space Station, is set to lift off at 4:58 p.m. EDT from Florida's Cape Canaveral. The event is being webcast live by both NASA and SpaceX and streamed on Space.com.
Lunar
eclipses occur, on average, about twice a year, but are rarely total. There are three types:
● A penumbral eclipse is when the moon passes through the
pale outskirts of Earth's shadow. It's so subtle, sky watchers often don't
notice an eclipse is underway.
● A partial eclipse is more dramatic. The moon dips into the core of Earth's shadow, but not all the way, so only a fraction of the moon is darkened.
● A total eclipse, when the entire moon is shadowed, is best of all. The face of the moon turns sunset red for up to an hour or more as the eclipse slowly unfolds.
● A partial eclipse is more dramatic. The moon dips into the core of Earth's shadow, but not all the way, so only a fraction of the moon is darkened.
● A total eclipse, when the entire moon is shadowed, is best of all. The face of the moon turns sunset red for up to an hour or more as the eclipse slowly unfolds.
According
to astronomer and noted eclipse expert Fred Espenak, the moon "can take on
a dramatically colorful appearance from bright orange to blood red."
Why
blood red?
"Imagine
yourself standing on a dusty lunar plain looking up at the sky," Tony
Phillips explains on NASA's Science News. "Overhead hangs
Earth, nightside down, completely hiding the sun behind it. The eclipse is
underway. You might expect Earth seen in this way to be utterly dark, but it's
not. The rim of the planet is on fire! As you scan your eye around Earth's
circumference, you're seeing every sunrise and every sunset in the world, all
of them, all at once. This incredible light beams into the heart of Earth's
shadow, filling it with a coppery glow and transforming the Moon into a great red
orb."
According to Espenak, tetrads have become more frequent
during the 21st century, the last coming in 2004 and the next slated for
2022-2023. Seven more are expected before 2100. Compare that with the 300-year
period between 1600 to 1900, when there were no tetrads at all.
So how can you see the April 15 total lunar eclipse?
"One of the great things about lunar eclipses is that they are completely safe to view with the naked eye," Espenak writes on his website, Mr Eclipse.com. "No special filters are required to protect your eyes like those used for solar eclipses. You don't even need a telescope to watch the eclipse, although a good pair of binoculars will help."
So how can you see the April 15 total lunar eclipse?
"One of the great things about lunar eclipses is that they are completely safe to view with the naked eye," Espenak writes on his website, Mr Eclipse.com. "No special filters are required to protect your eyes like those used for solar eclipses. You don't even need a telescope to watch the eclipse, although a good pair of binoculars will help."
Source by www.yahoo.com
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