Image: Sky map
Starry Night Software
This sky map shows the location of Jupiter and the moon on Jan. 29, 2012 as they will appear together at 9 p.m. to skywatchers in mid-northern latitudes.
updated 1/28/2012 1:40:39 PM ET 2012-01-28T18:40:39

For the second time this month, the moon is going to pay a visit to Jupiter, the largest planet in our solar system.

On Sunday and Monday evenings, a fat, waxing crescent moon will appear to slide past the planet Jupiter. Of course, the moon is much closer to Earth than Jupiter and as such, can change its position against the background stars rather quickly.

In fact, relative to the background stars, the moon will appear to move east at roughly its own apparent width each hour — or about 12 degrees (on average) over a span of 24 hours. The sky map of Jupiter and the moon with this story shows how they will appear together at about 9 p.m. local time to observers in mid-northern latitudes.

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On Sunday evening, look for Jupiter hovering about 7 degrees to the upper left of the moon; on Monday evening, however, you'll note that the moon will be a similar distance from Jupiter, but will have shifted almost directly above it. As a benchmark, 10 degrees could be visualized as roughly the equivalent of your clenched fist held at arm's length. [ Skywatcher Photos: Jupiter & the Moon ]

Without a doubt, Jupiter and Venus are currently the bright evening "stars" in our sky.

Jupiter is perched at Venus' upper left during the early evening hours. The "King of the Planets" shines brightly enough — two-and-a-half times brighter than Sirius, the brightest star (itself located at dusk shining brilliantly low in the southeast sky). 

And yet, Venus is still nearly five times brighter than Jupiter. The two planets will be slowly edging closer together in the coming weeks. They'll appear closest to one another, just 3 degrees apart, March 13.

This week, Jupiter doesn't set until around midnight local time, which means it's still high enough at nightfall for steady images in a telescope; Jupiter is enveloped like Venus in a perpetual cloud cover. Broad cloud bands cross the planet and are visible even in a small telescope, appearing to cross its disk parallel to the planet's equator.

Jupiter's disk is noticeably flattened at its poles because the giant planet is turning so fast on its axis — once around every 9 hours 50 minutes. For comparison, if Earth rotated on its axis as fast as Jupiter, our day would be only 53 minutes long!

A small telescope should also reveal four of Jupiter's moons — the famous "Galilean Satellites" that were discovered by Galileo with his crude telescope in January 1610. 

It's always interesting to watch these four moons through a telescope as they appear to change their positions relative to each other from hour to hour and from night to night.

On Sunday night, for instance, if you train a telescope on Jupiter — or even steadily hold binoculars with at least 7-power magnification — you'll see two moons, Ganymede and Callisto, on one side of Jupiter, while the other two, Io and Europa, will be on the other side. But on Monday evening, three moons will be gathered on one side (Ganymede, Io and Europa) while Callisto sits by itself on the other side of the big planet.

Editor's note: If you snap an amazing photo of Jupiter and the moon, or any other skywatching target, and would like to share it with, contact managing editor Tariq Malik at

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.

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Photos: Month in Space: January 2014

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  1. Southern stargazing

    Stars, galaxies and nebulas dot the skies over the European Southern Observatory's La Silla Paranal Observatory in Chile, in a picture released on Jan. 7. This image also shows three of the four movable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: They reveal details that would otherwise be visible only through a telescope as large as the distance between them. (Y. Beletsky / ESO) Back to slideshow navigation
  2. A balloon's view

    Cameras captured the Grandville High School RoboDawgs' balloon floating through Earth's upper atmosphere during its ascent on Dec. 28, 2013. The Grandville RoboDawgs’ first winter balloon launch reached an estimated altitude of 130,000 feet, or about 25 miles, according to coaches Mike Evele and Doug Hepfer. It skyrocketed past the team’s previous 100,000-feet record set in June. The RoboDawgs started with just one robotics team in 1998, but they've grown to support more than 30 teams at public schools in Grandville, Mich. (Kyle Moroney / AP) Back to slideshow navigation
  3. Spacemen at work

    Russian cosmonauts Oleg Kotov, right, and Sergey Ryazanskiy perform maintenance on the International Space Station on Jan. 27. During the six-hour, eight-minute spacewalk, Kotov and Ryazanskiy completed the installation of a pair of high-fidelity cameras that experienced connectivity issues during a Dec. 27 spacewalk. The cosmonauts also retrieved scientific gear outside the station's Russian segment. (NASA) Back to slideshow navigation
  4. Special delivery

    The International Space Station's Canadian-built robotic arm moves toward Orbital Sciences Corp.'s Cygnus autonomous cargo craft as it approaches the station for a Jan. 12 delivery. The mountains below are the southwestern Alps. (NASA) Back to slideshow navigation
  5. Accidental art

    A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images we're used to seeing from the Hubble Space Telescope. But it's a genuine Hubble frame that was released on Jan. 27. Hubble's team suspects that the telescope's Fine Guidance System locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in a remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288. (NASA / ESA) Back to slideshow navigation
  6. Supersonic test flight

    A camera looking back over Virgin Galactic's SpaceShipTwo's fuselage shows the rocket burn with a Mojave Desert vista in the background during a test flight of the rocket plane on Jan. 10. Cameras were mounted on the exterior of SpaceShipTwo as well as its carrier airplane, WhiteKnightTwo, to monitor the rocket engine's performance. The test was aimed at setting the stage for honest-to-goodness flights into outer space later this year, and eventual commercial space tours.

    More about SpaceShipTwo on PhotoBlog (Virgin Galactic) Back to slideshow navigation
  7. Red lagoon

    The VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile captured this richly detailed new image of the Lagoon Nebula, released on Jan. 22. This giant cloud of gas and dust is creating intensely bright young stars, and is home to young stellar clusters. This image is a tiny part of just one of 11 public surveys of the sky now in progress using ESO telescopes. (ESO/VPHAS team) Back to slideshow navigation
  8. Fire on the mountain

    This image provided by NASA shows a satellite view of smoke from the Colby Fire, taken by the Multi-angle Imaging SpectroRadiometer aboard NASA's Terra spacecraft as it passed over Southern California on Jan. 16. The fire burned more than 1,863 acres and forced the evacuation of 3,700 people. (NASA via AP) Back to slideshow navigation
  9. Where stars are born

    An image captured by NASA's Spitzer Space Telescope shows the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This false-color infrared view, released on Jan. 15, spans about 40 light-years across the region. The brightest portion of the nebula is centered on Orion's young, massive, hot stars, known as the Trapezium Cluster. But Spitzer also can detect stars still in the process of formation, seen here in red hues. (NASA / JPL-Caltech) Back to slideshow navigation
  10. Cygnus takes flight

    Orbital Sciences Corp.'s Antares rocket rises from NASA's Wallops Flight Facility on Wallops Island, Va, on Jan. 9. The rocket sent Orbital's Cygnus cargo capsule on its first official resupply mission to the International Space Station. (Chris Perry / NASA) Back to slideshow navigation
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  12. Frosty halo

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    Slideshow: The Year in Space (Brian Peterson / The Bismarck Tribune via AP) Back to slideshow navigation
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