The Hunter's moon rises nearly or completely full over three successive nights at nearly the same time each night. On Eastern Daylight Time this year, the nights of the 27th, 28th, and 29th, at 5:21, 5:57, and 6:35, respectively. Full moon is today at 3:50 p.m. EDT, but this shot was taken last night right around 10 p.m. my awesome new moon globe, it's hard to make out Clavius way down there on the bottom.) I'll have to try again tonight, perhaps with higher magnification. Here's the full moon gallery to date; I've only missed a couple since December 2009!
Last Tuesday the second planet from the sun passed in front of the sun's disk for the second and last time this young century. Back in 2004, I saw the first event briefly while parked outside a gas station trying to get out from under the clouds that had blocked us at our chosen observing site in Florida. This time, I was pretty sure I could do a better job: a planned trip to relatively cloudless California coincided nicely with the timing of the event, and I had even planned enough time to land, enjoy the customary In-N-Out lunch at the airport, then make the long drive up to our home base (the in-law's home in Atascadero) with an hour or so to spare before the event began. Of course, things did not work out as planned. Although I was able to find the binocular filters I'd made years ago out of surplus Baader film, my full-aperture white-light filter made at the same time went missing before the trip. So I needed a last-minute replacement for that. Here are the binocular filters; although they were made for different binoculars, the loving attention to detail and high-cost materials (cardboard tubes ain't cheap!) meant I had to recycle them:
NASA's next Mars mission is set for takeoff. The Mars Science Laboratory (nicknamed, for some insane reason, "Curiosity," as in what killed the cat) has a launch window that opens tomorrow, November 25, and closes a few weeks from now, on December 18. This rover is quite a bit bigger than the last set of rovers, Spirit and Opportunity, with a correspondingly more ambitious science mission. But what's really interesting is the planned landing method: according to the mission website,
The spacecraft will descend on a parachute and then, during the final seconds prior to landing, lower the upright rover on a tether to the surface, much like a sky crane.That doesn't sound risky, does it? It's also powered by the radioactive decay of plutonium instead of solar panels, so while the power source is more reliable (no dust storms or weather conditions should interfere), it's also relatively time-definite. Once the plutonium runs out, the mission ends. The science team is coy about the lifespan, calling it only "a full martian year (687 Earth days) or more." Assuming the rover survives the "sky hook" landing, though, the plutonium-powered mission should be pretty robust, with
significantly greater mobility and operational flexibility, enhanced science payload capability, and exploration of a much larger range of latitudes and altitudes than was possible on previous missions to Mars.Here is an artist's conception of the robot: With a planned arrival on the red planet in August 2012, we won't have long to wait before we find out whether curiosity will be satisfied, or, well... you know the saying about what happened to the cat!
October's full moon this year, the Hunter's moon, occurred at 10:06 p.m. EDT, about 9 hours before it reached apogee (Oct 12 7:44 a.m. EDT, distance 406 434 km). Local conditions here in south Florida were a bit of a challenge; I had to set up under clouds and hope for a break in the clouds near the time of full moon, which is when I wanted to take the picture. After all, it isn't often that the moon is exactly full at a convenient time for picture-taking. Some things fell in my favor: I had completed my field battery over the weekend, so my scope had its larger, more stable and, most importantly, tracking, mount from which to operate. Here's a picture of the battery setup: Harvest Moon last month, the time of the Hunter's Moon rise over the three nights around full is closer together than at other times of the year: 6:01, 6:33, and 7:08 for my location in Boca Raton; compare that to the situation for March's full moon, which rose successively at 5:37, 6:44, and 7:52, more than an hour later each night.
The full moon for August 2011 (Sturgeon Moon, Dog Days' Moon, etc.) occurred during the afternoon hours of August 13 (2:57 p.m. to be precise) for East Coast observers, so I did my usual day-before-just-in-case-the-day-after-doesn't-work photo, and I'm glad I did. The "night" of the full moon, the 13th, was much stormier and less conducive to photos than the night of the 12th, despite the very brief window I had on Friday (only about 5 minutes in the clear). Here, then, is a snapshot in haste of August 2011's 18-hours-before-full moon:
A rare celestial event occurred early this morning, so I thought I'd try my hand at capturing some images. I spent about an hour making sure my telescope mount was as close to polar aligned as I could make it. I balanced the heavy scope on the tube and aligned the spotting scope, the one through which I would be taking the images, with the main scope, so the computerized alignment would proceed smoothly. I took a few practice shots of the full moon about 5 hours before the event would occur: full moon during the September equinox earlier this year, so I've had some good luck already with shooting the moon while it's been in sync with the seasons. Still and all, a lunar eclipse is a pretty exciting event to witness, so it would be nice to have a personal record of it... Imagine my pleased surprise, then, when my eyes popped open at 3 a.m., and I was able to get dressed and get outside in time to see the first lunar eclipse on the solstice in 456 years. Without all the prep work, there would have been no chance to capture any images at all. As it is, I got two barely usable shots:
The December solstice, shortest day of the year is tomorrow, December 21. At approximately 7:38 p.m. EST (2338 UTC), the Sun's apparent motion in the sky will come to a standstill (Latin, solstitium).* That's because it has finished its southward migration for the year, and from here until June old Sol will travel north. And as it does so, days in the northern hemisphere will get longer. The image below, from an excellent NASA website, shows the paths of the sun on the longest and shortest days of the year: a total lunar eclipse. The moon is scheduled to be entirely within the earth's shadow (see image below) between 2:41 and 3:53 a.m. EST: a full 72 minutes of muted glory! During totality, the southern half of the moon will be much darker than the northern half, as Fred Espenak explains:However, the solstice is an event that, while observable on relatively long time scales, is not so interesting to the observer at any given moment. But early tomorrow morning there will be a much more immediately observable event:
From the eclipse diagrams shown earlier, it is clear that the southern (bottom) edge of the Moon will dip much deeper into the Earth's shadow than will the northern (top) edge. Since Earth's umbral shadow is darker in the center than at the edge, the Moon's appearance will likely change dramatically with time as the total phase progresses. A large variation in shadow brightness can be expected and observers are encouraged to estimate the Danjon value at different times during totality (Danjon Brightness Scale). Note that it may also be necessary to assign different Danjon values to different portions of the Moon at different times. This could be an excellent opportunity for budding astronomers and students to test their observing skills. Try recording your estimates of the Moon's brightness every ten minutes during totality using the Danjon Scale. Compare your results with your companions and classmates and discover how the Moon's appearance changes during the total eclipse. The brightness of the totally eclipsed Moon is very sensitive to the presence of volcanic dust in Earth's atmosphere. As part of a continuing research project, Dr. Richard Keen has been using reports of lunar eclipse brightnesses to calculate a history of optical thicknesses of volcanic dust layers (see: What Will 2004's Lunar Eclipses Look Like?). If you'd like to help Dr. Keen by making eclipse observations, you can contact him at Richard.Keen@colorado.edu.Now, as you probably know, lunar eclipses only occur during a full moon. So at midtotality, 3:13 a.m., the last full moon of the year will occur, only 16 hours or so before the official moment of the solstice. When will there be another lunar eclipse during the December solstice? I have no idea. But to show you how rare even the possibility of such an event is, the next full moon scheduled within 24 hours of the December solstice will take place in 2094. (The last one occurred in 1991.) I read somewhere online that there were only 7 full moons on the December solstice between 1900 and 1999, but I haven't fact-checked that claim. And I should, because that actually seems like a pretty strong correlation, when you consider that there "should" be only 1 full moon on the solstice every 29.5 years, given that the moon takes 29.5 days to go from full to full. Either the claim is wrong, or my understanding of math is wrong, or both are wrong. [UPDATE: For an AMAZING pictorial explanation of the event, check out today's Astronomy Picture of the Day from NASA. The text there answers my speculation above: 456 years since the last solstice eclipse, but no idea when the next will be.]
Here is a snapshot of the Hunter's Moon, taken on a breezy night on an old/new tripod. I'm not sure why focus was so hard to achieve; in the camera everything looked fine. I'm thinking there's some unidentified shake in the tripod or head. Will have to troubleshoot. Anyhoo, here 'tis:
Well, tonight I'm definitely dragging out the big telescope. Jupiter, which I only chanced upon the other day while shooting the moon, is only about 2 degrees from Uranus! I overlooked it, as had dozens of observers prior to Herschel's discovery of the planet in the 17th century. But now that I'm alerted to its close proximity to its more prominent celestial "neighbor," I'll try to take a look tonight. Hope you enjoy your evening! Don't expect pictures, although I'll certainly try; I had enough trouble getting Uranus to come out right... [UPDATE: As I suspected, Uranus was an underwhelming target, both telescopically and photographically. It was hard even to be sure I was looking at a planet instead of a star, except I could discern, with ever so much concentration, effort, and good will, a glimmer of a disc. And, to be sure, it wasn't twinkling at all, although the seeing was a bit muddy. Granted, knowing that I was looking at a giant ball of gas halfway across the solar system still made it fun to contemplate, but it wasn't a spectacle for the eyes; just the brain. I did manage to get a poor image of Jupiter with a moon (I'm fairly sure it was Io) in shadow transit. At the eyepiece, it was so much more crisp and beautiful than in the snapshot. Near the end of the session you could see the moon emerging on the limb, and it was just astonishing. Of course it doesn't show up at all in the photograph, but at least you can see the shadow itself:
Two images of last night's full moon appear below. One was taken a few minutes before the equinox; the other was taken a few seconds after it. Can you tell which is which? (Hint: the moment at which the equinox occurs has no bearing on the appearance of the moon.)