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This article, written by Jimmy Westlake, was also selected by High Country News as well as being featured on the front page of the Steamboat Pilot:

NASA has declared 2011 to be the Year of the Solar System (YSS) because of an unprecedented number of space missions to planets, moons, comets, and asteroids that will either culminate or begin this year.  The coming year is full of cool cosmic events, both natural and NASA-made.  Allow me to condense this long list down into my “Top Ten Cosmic Events for 2011.”   Here they are, in chronological order.

Jan 8-9:  Double Morning Stars – The solar system’s two innermost planets, Mercury and Venus, behave differently than the rest of the planets.  Instead of being free to wander all the way around the sky, they are tethered to the Sun so that they seem to swing out from one side of the Sun to the other and back again.  Consequently, each planet spends a brief time as our “evening star,” followed by a brief engagement as our “morning star.” The best time to catch each planet is when it is near its greatest angular distance from the Sun in our sky, an event called greatest elongation.  Even at greatest elongation, Mercury is never more than 28º and Venus never more than 48º from the Sun.  In early January, both planets will reach their greatest elongations west of the Sun within one day of each other, providing an unusual opportunity to see both Mercury and Venus at their best.  Before dawn on January 8, dazzling Venus will stretch 47º west of the Sun and rise more than three and a half hours before the Sun does.  The very next morning, January 9, Mercury reaches its greatest elongation 23º west of the Sun, rising about one and a half hours before the Sun.  On either morning, if you face the southeast around 6:15 am and have a clear view to the horizon, you can spot both planets glimmering in the multi-colored dawn sky.  Take a few moments to just gaze in wonder at the double morning stars.

Feb 14:  To the Heart of a Comet – This Valentine’s Day, NASA plans on shooting an arrow through the heart of a comet, figuratively speaking.

After successfully returning a sample of Comet Wild 2 to Earth in 2006, the Stardust spacecraft will visit Comet Tempel 1 on Valentine's Day and beam back closeup images of the comet's nucleus. (NASA image)

The target – Comet Tempel 1.  The arrow – the Stardust spacecraft.  If these names sound familiar, they should.  Comet Tempel 1 was already the target of the Deep Impact spacecraft back in 2005, which blasted a hole in the side of the comet with an 800-pound copper bullet and splattered comet dust all over the inner solar system.  The Stardust spacecraft was the first to return a sample of a comet to Earth in 2006 after swooping through the dusty tail of Comet Wild 2.  Now, in an historic example of cosmic recycling, the Stardust spacecraft has been re-targeted for the same Comet Tempel 1 visited by Deep Impact.  The follow-up mission hopes to accomplish several scientific goals, not the least of which is to get a clear view of the crater blasted out by Deep Impact.  Also, using the same spacecraft instrumentation to explore two different comets will tell us a lot about the differences and similarities between comet nuclei.  Watch the news media for amazing close-up images and visit the Stardust Mission home page for more details: http://stardustnext.jpl.nasa.gov/

This March, NASA's MESSENGER spacecraft will become the first ever to orbit the sizzling innnermost planet, Mercury. From orbit, MESSENGER will completely map the surface of Mercury and study the space environment around it. (NASA image)

Mar 18:  A MESSENGER for Mercury – Someone at NASA had to really stretch their imagination to come up with an acronym for their Mercury-bound spacecraft, MESSENGER.  The letters stand for MErcury Surface, Space Environment GEochemistry and Ranging.  Launched from Earth on August 3, 2004, MESSENGER has been swinging around Earth and Venus in an epic game of celestial billiards for the last six years in order to get MESSENGER to its target, the innermost planet, Mercury.  MESSENGER actually has zoomed past Mercury three times in the intervening years since its launch, but during its next pass on March 18, MESSENGER will fire its braking engine and become the first space probe to ever orbit Mercury.  From orbit, MESSENGER will be able to thoroughly map Mercury’s surface, determine the composition of its surface rocks and minerals, and study the nature and source of its magnetic field.  Mercury has been largely unexplored territory for decades, since the only previous spacecraft to zoom past it, Mariner 10, was way back in the mid 1970s.  Stay tuned to the news media as March 18 approaches for spectacular photos and science from our Mercury MESSENGER.  For more information, check out NASA’s MESSENGER Mission home page: http://messenger.jhuapl.edu/.

Apr 3:  The Rings of Spring – Once every 378 days, the Earth gains a lap on the sluggish planet Saturn and passes directly between Saturn and the Sun, placing the two planets as close together as possible.  This alignment of worlds is called opposition.  When Saturn reaches opposition on April 3, it will be 804-million miles from Earth, its closest point for 2011.  Saturn will rise in the eastern sky at sunset and shine in our sky all night long amongst the stars of the constellation of Virgo, not far from the equally bright stars Arcturus and Spica. Any telescope aimed at Saturn will reveal the beautiful system of rings encircling its equator and the largest of its many moons, the giant Titan.  After turning themselves edgewise to Earth in 2009 and briefly disappearing from view, the rings are opening up to us again, in all of their splendor.  So what are you waiting for?  Point that telescope at Saturn this April.  You won’t believe your eyes.

During the first three weeks of May, the planets Venus, Mercury, Mars, and Jupiter will cluster in our predawn sky for some spectacular groupings. Last August, a similar gathering of planets graced our evening sky. Seen in this image are the crescent Moon and the bright planet Venus, with Mars to Venus' upper left and Saturn to her right. Photo by Jimmy Westlake 2010.

Apr 30:  A Parade of Planets – During the last week of April and the first two weeks of May, our predawn sky will be buzzing with activity as the planets Mercury, Venus, Mars, and Jupiter cluster together and glide past each other in apparent near collisions.  Of course, most of the drama is overplayed since these planets are really millions of miles apart and their close proximity in our sky is merely a line-of-sight trick.  Still, to see that many bright planets in such a tight grouping is a remarkable sight and one that you will not soon forget.  The fun begins around 5:00 am on April 30, when the thin crescent Moon and Venus first rise above the eastern horizon.  Mercury follows moments later and the Mars-Jupiter pair appears after that.  The Moon, Venus and Jupiter should be easy to spot, but Mercury and Mars will be a little more challenging in the brightening sky.  Over the next three weeks, watch for Mars to pass only 0.4º from Jupiter on May 1, Mercury to pass 1.5º from Venus on May 7, Jupiter and Venus to pass within 0.5º of each other on May 11, Mercury to pass 2º from Mars on May 21, and Mars to pass only 1º from Venus on May 23.  Saturn is the only naked eye planet not participating in this planet parade.  He has the evening sky all to himself and is still basking in his own spotlight after his April 3 opposition.

When NASA's Dawn spacecraft arrives at the asteroid Vesta next August, our eyes will be opened to this mysterious world for the first time. After orbiting Vesta for a year, Dawn will move on to the dwarf planet Ceres and shed light on the dawn of our solar system. (NASA image)

Aug 14:  Dawn at Vesta – NASA’s Dawn spacecraft has been maneuvering toward the mysterious asteroid Vesta since its launch on September 27, 2007.  Vesta is the second largest of the thousands of asteroids that circle the Sun in the asteroid belt between the orbits of Mars and Jupiter.  Hubble Space Telescope images of this Colorado-sized asteroid reveal tantalizing hints of bright craters and dark lava flows and what appears to be a colossal impact crater at Vesta’s south pole.  The central mountain peak in this gaping 300-mile diameter hole rises 11 miles high, twice the height of Earth’s Mt. Everest!  About 200 space rocks called HED meteorites that have fallen to Earth are thought to be fragments thrown out from this violent impact.  The Dawn spacecraft will arrive at Vesta and settle into orbit around it on August 14.  After scrutinizing Vesta’s surface and environment for eleven months, Dawn will again fire up its ion engine and depart for its second target, the largest of the asteroids and dwarf planet designate, Ceres.  Dawn will arrive at Ceres in February 2015 and will orbit and study this water-rich world for several more months.  By exploring these two enigmatic mini-worlds in the asteroid belt, we hope to learn more about the history of our own world and the dawn of our solar system, hence the spacecraft’s name.  Watch the news media as August 14 approaches and, for more information, visit NASA’s Dawn Mission home page: http://dawn.jpl.nasa.gov.

Last June, the brilliant Evening Star, Venus, slipped past the Beehive star cluster, as seen in this image. A similar spectacle is in store for us on October 1, when the red planet Mars will pass through the swarming stars of the Beehive. Photo by Jimmy Westlake, 2010.

Oct 1:  Mars in the Beehive – The heavenly highway used by the Sun, Moon, and planets as they whirl around the sky passes through the twelve constellations of the zodiac.  Along this path, there are four glittering star clusters through which the planets can occasionally pass:  the Pleiades, the Hyades, M35, and the Beehive.  I am partial to these close encounters between planets and star clusters because the sight of a bright planet surrounded by dozens of twinkly little stars just makes me smile.  So, I am looking forward to the morning of October 1 when the red planet Mars will pass right through the middle of the Beehive star cluster in Cancer the Crab.  Any time between 3:00 am and dawn that morning, you will find Mars and the Beehive high in the eastern sky.  Although Mars is very bright and the Beehive is faintly visible to the unaided eye, binoculars or a small telescope will be required for the best view of this event.  The telescopic view should resemble a bag full of sparkling diamonds with one big, radiant ruby in the mix.  See if the sight of Mars in the Beehive doesn’t make you smile, too.

On October 7-8, the Draconid meteor shower could burst forth with a strong display of several hundred meteors per hour. The last time we enjoyed such a spectacle was in November 2001 when the Leonid meteor shower became a meteor storm of over 1000 meteors per hour. One bright and colorful Leonid meteor was captured in this image as it burned up high in Earth's atmosphere. Photo by Jimmy Westlake, 2001.

Oct 7-8:  Catch a Falling Star – 2011 is a dismal year for meteor watching, as the full or nearly-full moon spoils all of our favorite annual meteor showers – the August Perseids, the November Leonids, and the December Geminids.  The one bright spot for meteor watchers this year comes from what is usually a minor meteor shower called the Draconids.  If forecasters are right, we could be in for a spectacular rain of meteors on the night of October 7-8.  Sometimes, when the Draconids’ parent comet, Giacobini-Zinner, comes close to Earth as it will this year, we get pelted with a swarm of cometary dust particles.  Estimates for this year’s shower predict up to 750 meteors per hour streaking across the sky!  That’s the good news.  The bad news is that the peak is expected to occur over Europe, not North America.  Still, the prospects for seeing dozens to scores of meteors per hour over the USA should be enough to get any meteor enthusiast out of doors and looking up.  The Draconid meteors will seem to rain down from the head of Draco the Dragon, not far from the bright star Vega, high in our northwestern sky after sunset and, yes, the bright nearly-full Moon will interfere somewhat, but just put the Moon to your back and watch the sky anyway.  Get out there the night of October 7-8 and catch a falling star… or two.

Oct 28:  The Halloween King – Venus has the distinction of being the brightest planet visible in earthly skies, but Venus is always seen near the horizon at dusk or dawn, never high overhead in our midnight sky.  Jupiter wears the crown when it comes to ruling the midnight sky, and Jupiter will be at its closest point to Earth, and thus brightest in our sky for 2011, on October 28 when it reaches opposition.  For several weeks around that date, Jupiter will rise in the east as the Sun goes down in the west and gleam brilliantly high in our midnight sky.  On the night of opposition, Jupiter will be a mere stone’s throw from Earth, about 371-million miles.  Steady binoculars or any small telescope will reveal Jupiter’s four traveling companions, discovered by Galileo in 1610.  They are Io, Europa, Ganymede, and Callisto – the four largest of Jupiter’s 63 known moons.  Watch from night to night as the moons constantly shift their positions around Jupiter.  With a medium-sized telescope, you can also see the two main cloud stripes straddling Jupiter’s equator and maybe even the famous Great Red Spot.  This autumn, Jupiter will shine down on us from the constellation of Aries, the Ram.  Look for a distinctive little triangle of bright stars just above Jupiter.  That’s Aries.  When you are out trick-or-treating this Halloween, glance up at that dazzling planet lighting your way after dark.  It’s Jupiter, the king of the Halloween sky.

The total lunar eclipse visible from Colorado on December 10, 2011 will be visible up to, but not including totality, unlike the total eclipse that we all enjoyed this past December 21. In this series of images, the Moon is shown just before, during, and just after totality. Photos by Jimmy Westlake, 2010

Dec 10:  A Brush with Totality – 2011 is a six-eclipse year, with 4 partial solar eclipses and two total lunar eclipses.  North America, though, is on the wrong side of the Earth for all of these eclipses, save one – on the morning of December 10, the western USA will get to see the first half of a total eclipse of the Moon.  Unlike the spectacular total lunar eclipse we just enjoyed this past December 21, the Moon next December 10 will set for Coloradoans just as the total phase of the eclipse begins.  Early risers can watch the eclipse begin in a dark sky at 5:46 am MST, when the top edge of the Moon will begin to darken as it slips into the Earth’s shadow.  Then, as the eclipse progressively gobbles up more and more of the full Moon, the sky will begin to brighten with the morning dawn.  Eventually, the sky will become so bright that the eclipsed moon will likely fade from view as it sinks toward the western horizon.  Totality begins at 7:06 am, the Sun rises at 7:18 am, and the Moon sets at 7:21 am.  Lousy timing for folks living in northwest Colorado, but perfect for folks living in Alaska and Hawaii who will get to see the entire eclipse. This is the closest that we will come to a total lunar eclipse until April 15, 2014, so you’d better enjoy this brush with totality.

Of course, there is always the chance that a bright comet or aurora or supernova will surprise us this year, so keep an eye on the sky.  Be sure to check the NASA websites http://spaceweather.com/ and http://antwrp.gsfc.nasa.gov/apod/astropix.html often for updates and photographs of these and lots of other exciting celestial events.

Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College’s Alpine Campus. He is an avid astronomer whose photographs and articles have been published all around the world. His “Celestial News” column appears weekly in the Steamboat Today newspaper and his “Cosmic Moment” radio spots can be heard on local radio station KFMU. For a full-color wall calendar of celestial events in 2011 featuring some of Jimmy’s best astrophotos, check out his website, www.jwestlake.com.