JANUARY  2008

JANUARY STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

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Current Moon Phase

Comet 8P/Tuttle will be visible for the next week or so before it eventually disappears in the southwest in late January. Catch it now with binoculars or small telescopes from rural and suburban locales. Tuttle appears as a fuzzy smudge in small binoculars. The comet images on the map are strictly for location purposes and do not represent how the comet will appear to the unaided eye or through binoculars. Map drawn by Gary A. Becker using "The Sky"...

Tuttle in Stereo:   These two photos of Comet 8P/Tuttle will “pop” into a stereo image by crossing your eyes to produce a third image between the left and right pictures. The comet will appear to be three dimensional and lie in front of the stellar background. These two pictures, separated by only seven minutes in time, were taken with a Canon 40D camera on January 2 just after 9 p.m. EST. Photography by Gary A. Becker, Coopersburg, PA…

594a  JANUARY 6, 2008:   Shout-Out for Mercury

There are two good reasons for keeping an eye on Mercury this month. The first will be its visibility throughout much of January in the southwest after sundown. The other is NASA’s MESSENGER probe scheduled to rendezvous with Mercury on Tuesday, January 14. The last space visitor to this moonlike world was Mariner 10 in 1975. I will be discussing the MESSENGER mission in next week’s StarWatch. The Mercury show starts off with an elusive bang this Wednesday when an ultra thin crescent moon hangs just two and a half degrees to the left of Mercury. You’ll need an unobscured southwestern horizon, binoculars, and very clear skies, not the easiest conditions to come by in dreary January. Be at your designated observing location no later than 5:10 p.m., about 20 minutes after sundown. Start scanning the horizon to the left of the sunset glow, and then one binocular field above. Any starlike object encountered will be Mercury. With Mercury centered, the moon will be in your binocular’s field of view at the 10 o’clock position. Mercury continues to gain prominence, giving its best performance between the dates of January 19 and 26 when it should be an easy find under clear skies about 45 minutes after sunset. Another highlight of this Mercury elongation will occur on Tuesday, January 22, when the Messenger god is positioned only 1/4-degree from the planet Neptune. To see Neptune, you’ll need a small telescope or a camera capable of taking an exposure of five to 10 seconds in length. You should have your telescope fully set up and looking for Mercury by 5:50 p.m. or about 45 minutes after sundown. Mercury will about one fist held at arm’s length above a true WSW horizon. The brightest starlike object that appears along with Mercury in the same field of view will be the planet Neptune.

594b  JANUARY 10, 2008:   Shout-Out for Mercury

There are two good reasons for keeping an eye on Mercury this month. The first will be its visibility throughout much of January in the southwest after sundown. The other is NASA’s MESSENGER probe scheduled to rendezvous with Mercury on Tuesday, January 14. The last space visitor to this moonlike world was Mariner 10 in 1974-5. I will be discussing the MESSENGER mission in next week’s StarWatch. The Mercury show started off this week with an elusive bang on Wednesday when an ultra thin crescent moon hung just two and a half degrees to the left of Mercury. After several days of unseasonably warm but mostly cloudy evenings, the skies cleared spectacularly. I found a location with a perfect southwestern horizon and began imaging the moon about 20 minutes after sunset. Mercury became visible five minutes later, and as the sky reddened, settled amongst the skeletal branches of distant trees. Pictures are posted online at the URL below. Simply click on the “this week’s StarWatch” button. Mercury continues to gain prominence, giving its best performance between the dates of January 19 and 26 when it should be an easy find under clear skies about 45 minutes after sunset. Another highlight of this Mercury elongation will occur on Tuesday, January 22, when the Messenger god is positioned only 1/4-degree from the planet Neptune. To see Neptune, you’ll need a small telescope or a camera capable of taking an exposure of five to 10 seconds in length. You should have your telescope fully set up and looking for Mercury by 5:50 p.m. or about 45 minutes after sundown. Mercury will be about one fist held at arm’s length above a true WSW horizon. The brightest starlike object that appears along with Mercury in the same field of view will be the planet Neptune.

The moon and Mercury meet briefly after a beautiful sunset near Coopersburg, PA. Mercury can be found just below tree level, right of center in the picture. A Canon D40 camera was used in conjunction with an equatorial mount and a telephoto lens at an effective focal length of 320mm. The January 9 exposure was two seconds at F/5.6, ASA 1000. Gary A. Becker image...

Earthshine can still be seen on this image of a 35-hour moon as it sets behind skeletal trees west of Coopersburg, PA. A Canon D40 camera was used piggybacked to an equatorial mount. A 640mm lens at F/5.6, ASA 1000 was used to take this 3.4 second image. Photography by Gary A. Becker...

595    JANUARY 13, 2008:   Mercury's New MESSENGER

Mercury, the most elusive planet in our solar system, and last visited in the mid-1970s, has a new messenger which hopefully will begin to answer questions about its surface chemistry, magnetic field, internal structure, and formation in our solar system. Since August 3, 2004, NASA’s MESSENGER space probe, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging satellite has been steering a convoluted path towards the Messenger god, making two passes around Venus and one around the Earth so it could accelerate and achieve the proper orientation for a gravitational capture on March 18, 2011. On Tuesday, MESSENGER will make the first of three flybys of Mercury before its permanent capture. Mercury was last imaged by the Mariner 10 spacecraft in 1974-5. This probe also completed three flybys of Mercury, returning images of 45 percent of the planet’s surface. Mariner 10 showed Mercury to be a cratered world that looked strangely moonlike in its character and history. However, it is known that Mercury’s internal structure is very different from Earth’s moon. It has the largest ratio of core to planet diameter in the solar system, and it possesses a magnetic field. An iron-nickel core for the moon is still being debated; however, if one exists, it most certainly will be small. The moon does not have a magnetic field. With MESSENGER’s high resolution camera, chemical “sniffing” spectrometers, a magnetometer to analyze Mercury’s magnetic field in 3-D, and laser altimeter, to determine accurately the planet’s topography, MESSENGER is posed to go where no spacecraft has gone before. Currently, you can catch the real Mercury in the southwest after sundown. Go online and read last week’s StarWatch at the URL below to learn about the specifics.

This three day old moon was photographed on January 11 and looks surprizingly like Mercury surface. This week Mercury's MESSENGER spacecraft should provide us with the most detailed images yet received. Photography by Gary A. Becker...

Photography by Gary A. Becker...

596    JANUARY 20, 2008:   M-Planets Visible

With the moon full on Tuesday morning, it’s time to focus on the bright evening planets. What is that reddish star above and to the right of the moon tonight? It’s Mars. Mars has been visible in the evening sky for quite a while, and as the Earth has come around to pass the Red planet, Mars has moved backwards or retrograded against the starry backdrop. We see this effect almost everyday when passing slower traveling vehicles moving in our same direction. If you observe the vehicle you’re passing, it will appear to slide backwards with respect to your car’s motion. Mars began retrograding in mid-November as the Earth passed it. On January 31, Mars begins its direct motion towards the east again. By 8:30 p.m., this week, it lies directly above Orion the Hunter in the south and just 2.5 degrees below and to the left of the bright star Elnath, the right or northern horn of Taurus the Bull. If you’re planet hunting during this full moon week, you cannot ignore Mercury which stretches nearly 19 degrees east of the sun on Tuesday and reaches perihelion, its closest position to the sun on Sunday, January 27. Unfortunately, Mercury grows dimmer as its geometry with the Earth and sun causes the Messenger god to change rapidly from a waning gibbous phase (more than half sunlit) to a thick waning crescent (less than half lit) by the week’s end. At month’s end, Mercury is still setting one hour after sundown, but its brightness has decreased to that of the stars in the Big Dipper, making it difficult to find. Using binoculars, look WSW by 5:45 p.m. Your horizon must be as free from obstacles as possible. Any starlike object found where sky and Earth meet will be Mercury. While planning your astronomical calendar, don’t forget the total lunar eclipse on Wednesday, February 20.

The light of a nearly full moon blends with twilight to provide an eerie scene as Mercury sets in the WSW at 6:17 p.m., on January 21. An equatorially driven mount was used with a Canon 40D camera and a lens that produced an effective focal length of 224mm. Two 20 second images were blended with and without the drive engaged to produce a steady sky and landscape. Photography by Gary A. Becker, west of Coopersburg, PA...

The moon's light lit up the landscape on January 20, the coldest evening of this year so far. The temperature was a lucky 13 degrees F. outside. Canon 40D image, 1/320 sec., F/8, ASA 200 by Gary A. Becker, Coopersburg, PA...

597    JANUARY 27, 2008:   Saturn on the Rise

Last week, I spoke about the M-planets, Mars and Mercury. Just one week later, Mercury has faded substantially and is poised to be at inferior conjunction, between the Earth and the sun, on February 6. While ruddy Mars continues to burn brightly in Taurus, there is another planet that will be coming into the limelight during the next several months, Saturn. The ringed world is currently located in Leo the Lion and rises this week about 8 p.m. However, give Saturn an hour or two to gain sufficient altitude so that it can be seen easily in the east. NASA’s Cassini orbiter has been circling Saturn since July of 2004 sending back data on its ring system, atmospheric circulation, magnetic field, and 60 satellites. Updates with copious photos on the Cassini mission can be found at http://saturn.jpl.nasa.gov/home/index.cfm. During the last half-dozen years, observers have been treated to spectacular vistas of Saturn’s rings. The planet has been tilted away from us, favoring views of its southern hemisphere and its wide open ice rings that have been seen from below the ring plane. At times we will be viewing the rings edgewise, and because of their thinness which is less than one mile, they will appear to disappear. At other times the rings will be seen as razor thin lines extending away from the planet. Presently, the rings can be seen in the smallest and least expensive of telescopes. Also set a date to be at the Quakertown Airport, along with your telescope on Wednesday, February 20. The ASD Planetarium’s StarWatch team will be observing the total lunar eclipse which begins at 8:44 p.m. The next several StarWatch articles will detail the eclipse and this event. And while the moon bleeds its reddish light into the night during mid-eclipse, Saturn will only be a scant four degrees away.