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) H( C$ ~7 ^. ?7 M: G; ]" @: dA sky-watcher gazes at Mercury (lower left) and Venus in the evening sky over Germany in October 2009.
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Andrew Fazekas
/ L0 I! Y2 j) b7 M7 C, D' M, c3 ifor National Geographic News# s/ a- @* D, W$ ], b( @# ?
Published April 1, 2010
! n9 _7 D( v& V; C, PNormally elusive, Mercury will be a "star" for most of April, shining brightly near Venus above the evening skyline.
0 p; E* B# Z, [/ y& z" k: rBoth planets will be visible to the naked eye for the next two weeks as bright, starlike objects that will dominate the low western sky shortly after sunset.$ R# x2 ]# `! ]8 L$ I' ~
"From a place with a low horizon, one should be able to get a nice view of these two planets hanging in the darkening sky like gems," said Geza Gyuk, staff astronomer at the Adler Planetarium in Chicago.
& t* B8 D9 I: u& @& r0 TAs the cosmic duo climb higher, the'll reach conjunction—their closest approach to each other—on Saturday and Sunday.
9 x# x8 n% f- Y6 l# \. @& ^! RThose nights the two planets will seem to be separated by only three degrees, or the equivalent of six full-moon disks.
" D0 f3 I( _) @0 n6 H" m* z6 ~* XVenus Guides Eyes to Mercury
; S+ Y3 B! G O0 cOf the five planets visible to the naked eye, Mercury is usually the most challenging to see, because it never wanders far from the sun.; }9 r- b8 x5 x# u2 h# W# k7 M: z
The innermost planet, Mercury orbits the sun so closely that a year lasts just 88 Earth days. (See pictures of Mercury taken by a passing spacecraft.)
2 j1 y/ u' q: k$ M! z1 \- e) v2 qAs seen from Earth, Mercury tightly hugs the horizon, and it appears faint because it's swathed in the sun's glare.
3 o# E7 X3 Z( g"Most people never get to see Mercury, because it ... isn't very bright. But this conjunction is coming around Mercury's maximum elongation [the planet's farthest angle away from the sun] of 20 degrees on April 8," Gyuk said.
5 a5 c4 e6 ~2 {Brilliant Venus will serve as a guidepost for sky-watchers to easily find tiny Mercury. (Related: "Neptune Easier to Spot Now, Thanks to Jupiter.")) {% Q+ u- x" f+ r
"Weather permitting," Gyuk said, "I'm certainly going to be out with my kids looking for Mercury!". m" g6 M, o# ^; L8 ?6 H' i7 z
Full Planetary Collection5 a; [ n w8 o, W1 A8 {6 T' c( @
As an added bonus, planet-hunters already out to spy Venus and Mercury will be able to see all five naked-eye planets in a single night.
1 A! R5 w9 x: t" o# N8 j1 sAs darkness sets in, Mars will become visible directly overhead, appearing as a red-tinged, starlike object. A little later, Saturn will appear slightly above the eastern horizon and will rise higher during the night., E: t& q0 U4 O5 y& h
(Related: "Sky-watcher Beware: Mars Email a 'Spectacular' Hoax.")8 ^0 m6 v) m/ s" W! E& Z
Finally, the gas-giant planet Jupiter will rise in the east just before sunrise |