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& j" D m8 n/ G" eA sky-watcher gazes at Mercury (lower left) and Venus in the evening sky over Germany in October 2009.; t+ C5 ^8 Z1 L, B
7 T* a; M8 A3 V) aAndrew Fazekas
5 v$ o/ ]/ l6 G( }. Gfor National Geographic News: \5 M4 g) u2 ^& O; p) e
Published April 1, 2010
2 e; E) I- g+ ^0 j p4 y7 i, [Normally elusive, Mercury will be a "star" for most of April, shining brightly near Venus above the evening skyline.
+ T6 S" B" N4 D' B w: q# q. dBoth 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.
/ }3 B9 W" r! P$ V"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.
' L. d$ Y# q' k' R9 b- F; kAs the cosmic duo climb higher, the'll reach conjunction—their closest approach to each other—on Saturday and Sunday.0 \: U* S, I! Q1 F7 o# E
Those nights the two planets will seem to be separated by only three degrees, or the equivalent of six full-moon disks.; M1 y+ C. T6 Q- z1 l& z
Venus Guides Eyes to Mercury6 ]% s/ T5 j* l
Of the five planets visible to the naked eye, Mercury is usually the most challenging to see, because it never wanders far from the sun., m% N- V2 F {6 r8 n
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.)
7 ^1 x* a9 ^! Q" m' x1 b0 @: K' iAs seen from Earth, Mercury tightly hugs the horizon, and it appears faint because it's swathed in the sun's glare.
' W) u1 D; E3 ~. \3 y2 u) U"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.
& s% O9 ?3 Z4 E# ABrilliant Venus will serve as a guidepost for sky-watchers to easily find tiny Mercury. (Related: "Neptune Easier to Spot Now, Thanks to Jupiter.")
! @8 l8 _8 ~3 u4 B4 ?"Weather permitting," Gyuk said, "I'm certainly going to be out with my kids looking for Mercury!"; d7 d3 _! q2 ~$ J
Full Planetary Collection8 S i( K* c" G# F$ k
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.: D" @7 y+ P2 L4 T5 M1 Z4 {
As 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.& @8 v8 U3 Y& U9 D! g' z) Z& T
(Related: "Sky-watcher Beware: Mars Email a 'Spectacular' Hoax.") z; f) r2 P4 T( j4 Q# i( F' p
Finally, the gas-giant planet Jupiter will rise in the east just before sunrise |