Moon And Jupiter Delight Plus How To See A Sick Satellite

A gargoyle carved into shape of an American Indian casts a shadow looking toward the moon late yesterday afternoon from downtown Duluth, Minn. Details: 400mm lens at f/32. Photo: Bob King

You never know where the moon’s going to pop up. Yesterday afternoon it played hide and seek with the buildings downtown as I walked around looking for a suitable place to frame a bit of heaven and earth. Both tonight and tomorrow night the waxing gibbous moon will be near the planet Jupiter high in the southeastern sky. The combination of bright moon and bright planet will definitely catch your eye.

The moon passes just a few degrees from Jupiter tonight and Tuesday night. Created with Stellarium

If you have binoculars, point them at Jupiter and look for three of its moon strung out to the upper left (east) of the planet. Telescope users can watch a pretty shadow transit of Io between 8-10 p.m. CST. Look for an inky black dot along the edge of the planet’s South Equatorial Belt slowly moving from east to west above the planet’s cloud tops. Io itself may also be visible to the west of the shadow if the air is very steady and you’re using at least a 6-inch telescope.

The layout of Jupiter's four brightest moons this evening.

It’s always good to get the ground truth about something we hope to see in the sky. I consider it essential for this blog, since we’re always talking about stuff that’s up there. Case in point is the Russian Phobos-Grunt probe still stranded in orbit. I’ve been waiting for a clear night and a bright pass of the craft for more than a week.

Last night it finally happened. I used the prediction from the Heavens Above website and the satellite was right on time, on track and matched its predicted brightness as it flew over the front yard. What surprised me was how fast the probe moved; it reminded me of a rock flying through the air. The speed was indicative of the P-G’s altitude which varies from 124 to 311 miles. When passing a locale on the lower, closer end of its orbit that thing can move! I also detected a bit of yellow-orange color from the gold foil or mylar insulation that covers the craft.

It was still twilight when Phobos-Grunt passed by last night, so its track (at top) is faint in the bright blue sky during the 30-second time exposure. Photo: Bob King

Phobos-Grunt was faint during first half of its track in the western sky, but as it traveled east and the angle between it and the sun widened, it steadily brightened. Sort of a “full moon” effect as applied to satellites. At best P-G shown brighter than the Big Dipper stars and was very easy to see.

If you haven’t seen it yet, I recommend you give it a try soon before the probe burns up in the atmosphere during re-entry sometime early next year. Although I’m sure the engineers in Russia involved in the probe are pained and embarrassed by P-G’s failure to fire rockets and head for Mars, when it comes to satellites, one’s troubles are in full view by anyone on the planet who cares to look. As it flew by, I was sad at a lost opportunity.

Ralf Vandebergh of the Netherlands used a telescope and tracking mount/software to capture this closeup image of the Russian probe during a pass on November 29. Credit: Ralf Vandebergh

If you’d like to see the probe, log in to Heavens Above, select your city and click on the Phobos-Grunt link. You’ll be shown a table of pass times and other information about direction, altitude and brightness. Remember that the smaller the magnitude number, the brighter the pass. Anything from magnitude 2 and under is easily visible. Click on the time link to go to a very handy map showing the satellite path in the sky, and use that as your reference when you’re outside. You can also use Visual SAT-Flare Tracker 3D or CalSky. All show similiar times and maps.

I’ve listed a few passes below for the Duluth, Minn. region. Bring binoculars if possible. With them, you should easily see P-G’s red hue.

* Tonight beginning at 5:04 p.m. in twilight. This pass is almost identical to the one I saw last night. You’ll start to see it at about 5:06 p.m. when it’s just below the North Star and moving quickly eastward (to the right as you face north). Maximum brightness of magnitude 1.8.
* Tuesday at 4:57 p.m. again in twilight which makes the early portion of the pass difficult to see. It will be brightest at 1st magnitude (!) when it passes through the W of Cassiopeia high in the northeastern sky around 4:59 p.m.

Tomorrow we’ll take a look at this coming Saturday’s total eclipse of the moon visible from much of the U.S., Asia, Australia and Eastern Europe. I’ll have maps and a helpful guide.