Archive for the ‘Jupiter’ Category


Observing report: All-nighter on Mount Baldy

July 15, 2012

Whew! Last night rocked. Terry Nakazono was out from LA, and we had been planning for about two weeks to spend the night observing up on Mount Baldy. We had made a shorter, half-night run up the mountain back in June, Terry to chase faint galaxies with his SkyScanner and me to log a few Herschel 400 objects with the XT10. Last night was basically the same plan, but on steroids–the moon was rising later, and neither of us had anywhere to be today. My wife and son were both out of town, she on work and he on a sleepover, so I was released on my own recognizance.

We got up there about 8:45 and met fellow PVAA member Craig Matthews setting up his 8″ Dob. Former PVAA president Ron Hoekwater joined us a little later on.

Terry was rolling with his SkyScanner again, and aiming for galaxies in Ursa Major and Bootes. I decided to leave the XT10 at home and take the Apex 127 Mak instead. I’ve had that scope for about a year, but before last night I had not really tried it out under dark skies. It did go to the Salton Sea in February, but we were mostly clouded out that night. Five inches is a lot of aperture under dark skies, and I was anxious to see what the Mak could do. Mount Baldy is not stupid-dark like Afton Canyon or western Arizona, but it’s not bad at all. The Milky Way was prominent and showed a fair amount of detail, especially after midnight when a strong marine layer at lower altitudes effectively halved the light pollution to the south (Inland Empire) and southwest (Los Angeles). On light pollution maps Baldy shows as being in the Orange zone, Bortle Class 5, but between the altitude and the marine layer it is sometimes effectively Green (Bortle 4). Last night was such a night.

I also took along the Celestron Travel Scope 70, which I had otherwise only used for quick peeks from my driveway. I’ve been meaning to blog about that scope. Right now you can get the scope, finder, two eyepieces, a tripod, and a backpack carrying case from Amazon for about $70 shipped. The finder is a travesty–an all-plastic “5×20” unit that is in fact stopped down to 10mm right behind the objective. I stripped the so-called optics out of mine and use it as a naked-eye sight tube, in which role it performs admirably, and a heck of a lot better than it ever did as a magnifying finder. The tripod is a joke, the sort of thing that gives other flimsy tripods a bad name. It struggles to hold a point-and-shoot digital camera steady, let alone a telescope, so I donated it to a museum. But the eyepieces are serviceable, the carry bag is fine, and the telescope itself is okay–more on this in the next post–so for $70 it is a screaming deal. As with the Apex 127, I was anxious to see what it could do under dark skies.

It was not yet fully dark when we arrived so I spent some time jawing with Craig. It was cloudless and clear where we were, but we could tell it was raining in the Mojave Desert, because the northeastern sky flickered with distant lightning. And we knew it was far off because we never heard even a hint of thunder. The lightning was not reflecting off clouds but off of the sky itself. It was as if the sky was on the fritz, like a bad florescent bulb. It was a profoundly weird and unearthly effect.

I started my observing run by putting the Apex 127 on Saturn. In addition to observing with “new” scopes, I was also rolling with genuinely new eyepieces. Explore Scientific has been having a CUH-RAY-ZEE sale on their well-reviewed 68, 82, and 100-degree eyepieces, so I sold some unused gear and bought a few: the 24mm ES68, which delivers the widest possible true field in a 1.25″ eyepiece, and the 14mm and 8.8mm ES82s. The Apex 127 is my longest focal length scope at 1540mm, so those eyepieces yielded 64x (24mm), 110x (14mm), and 175x (8.8mm). I also have a 6mm Orion Expanse that gives 257x–that is my default high-mag eyepiece in any scope. The ES eyepieces had just arrived in the mail last week so last night was my first time to try  them out.

Anyway, the seeing was limiting, with the view shaky at 175x and downright ugly at 257x, but Saturn was crisp and jewel-like at 110x and I could see four moons even at 64x. I haven’t checked the charts to see for sure which ones they were, but Titan certainly, and Dione, Rhea, and Tethys probably. I have seen up to five moons of Saturn at once before, but that requires steadier skies than we had last night.

After Saturn I hit a few favorite Messiers, including the globs M13, M5, and M4, all of which were impressively resolved for a 5″ scope. My favorite view of the evening through the Apex 127 was of the galaxies M81/M82 in the same field at 64x, with tantalizing hints of detail visible in both.

Then I got to work, finding and logging Herschel 400 objects. I was chasing mostly open clusters in Cygnus and Cassiopeia. I logged NGCs 6866, 7062, 7086, 7128, 7008 (a planetary nebula) and 7790. I also tried for open clusters NGC 7044 in Cygnus and 136 in Cassiopeia, but could not locate anything I felt comfortable calling a definitive open cluster at the charted locations amid the rich Milky Way starfields. This was also an issue with several of the Cygnus clusters I did log—at high magnification they tended to disappear into the surrounding star chains and asterisms.

Getting skunked is no fun, and by that time I’d been working on H400s for about two hours. For a change of pace, I switched over to the Travel Scope 70 and started plinking at Messiers. With a 32mm Plossl eyepiece I got 12.5x magnification and a stunning 4-degree true field–more like a finder on steroids than a telescope. I started with the Double Cluster as soon as I saw it was over the horizon, then hit M31, but didn’t immediately see its satellite galaxies. Then it was on to the “steam” rising from the teapot of Sagittarius: M8, M20, M22, M24, M25, M23, M18, M17, M16—these last three all nicely framed in the same field—M26, and M11 up in Scutum. Then back to the “bottom” of Scorpio and Sagittarius to catch M6 (M7 had already set behind a hill to the south—bummer), M69, M70, and M54, then all across the sky for M51, M101, M102, M13, M92, M15, back to Andromeda for a nice view of M31, M32, and M110 all prominent in the same field, M52, M103, M33, M76, and M34. I’d seen all these things before, but for most of them this was the lowest magnification I had seen them at, given that my binocular observations of them had mostly been with 15x70s. One of my favorite views of the night was M103 in Cassiopeia with NGCs 654, 663, and 659 in an arc below in the same field.

A little after 3:00 AM it was time for another goal: tracking down the outer giants. I had looked up the finder charts for Uranus and Neptune on Sky & Telescope’s website and logged their positions in my atlas. I found Neptune first, in Aquarius, using the Apex 127. Neptune was a very blue spark, and required 257x to appear non-stellar. Uranus, farther east in Pisces, was obviously non-stellar even at 64x. I also ran up to 257x on it, but the most pleasing view was at 175x. I had seen both planets before, but never as well, nor spent as much time on them as I did last night. Very strange to see giant Neptune as a tiny point of light in the mind-boggling darkness and immensity of space.

After observing planets I went back to the TS70 to continue the Messier survey. Logged M57, M56, M27, M45—absolutely stunning in the center of the field at low power—M72, M73, M2, M30, M75, M71—and old adversary from my early days with the XT6, but dead easy at low mag under dark skies—and M77. I tried for the faint face-on spiral galaxy M74 and suspected something there but couldn’t be sure. For a few these objects, including M72 and M77, I had to go up in magnification to pull them out of the skyglow or make sure they were not stars, using the 25mm (16x) and 17mm (23.5x) Plossls. I tried the 24mm ES68 but it was too heavy for the long cantilever from the mid-tube dovetail to the extended focuser tube of the TS70.

The last big show of the night was an upside-down kite shape rising in the east, with Jupiter at the top, Venus at the bottom, the thin crescent moon on the left, and Aldebaran on the right. I looked at the planets with the Apex 127 at 64x—the near-horizon seeing was bad but Venus’s crescent shape was well-defined, and Jupiter showed a couple of cloud bands and of course the four Galilean moons. Update: Pictures of this conjunction are posted here.

And that was it. The sky was rapidly getting brighter in the east, so we didn’t need artificial light to pack up. We pulled out at 5:25, went to Norm’s diner for breakfast, and I dropped Terry off at his hotel and went home for some badly-needed rack.

My final tally for the night was 8 new H400s, including NGCs 654 and 659; 44 Messiers, 42 of which I saw in the TS70; and 5 planets, including all four gas giants and Venus. Favorite observations were the flashing sky from over-the-horizon lightning, M81 and M82 in the same field in the Apex 127, M31 and both satellite galaxies in TS70, my best-yet views of Neptune and Uranus, and the dawn conjunction of planets, moon, and stars. Between dusk and dawn I observed five of the seven planets visible in a 5-inch scope, missing only Mars and Mercury (both were achievable, it turns out, I just didn’t try for them). It was a heck of a good night.

How did all the equipment perform? Stay tuned for the next post!


The King of Planets courts the Goddess of Love

March 13, 2012

For the next few nights, Jupiter and Venus are going to be as close together in the sky as they’ll get this year. I took this picture this evening from my driveway with my old Nikon Coolpix 45oo, about a 1 second exposure. Jupiter is on the left.

If you have optics, even small ones, you should be able to see the moons of Jupiter and see that Venus is a half-lit D-shape instead of a round ball of light.

I was out for a bit this afternoon and again this evening with the 90mm Sky Watcher Mak. I am learning to live with the finder, and the scope itself continues to impress. This is one of the sharpest bird photos I have ever taken:

The seeing was better tonight than it has been in a long time. I put the little scope on Jupiter and dropped in a 6mm eyepiece for 208x. Jupiter was razor-sharp and zebra-striped with cloud bands. In the steadiest moments, the South Equatorial Belt showed a ragged edge, and a small white storm notched its southern border. It was one of the most mesmerizing things I have ever seen with a small telescope.

As always, I am amazed that a little hunk of metal and glass the size of a 2-liter bottle can do so much. I have really missed having a little Mak around, and I don’t intend to be without one again.


SkyWatcher Mak 90–more pictures, and using the mount in manual mode

March 4, 2012

More pictures of the SkyWatcher 90mm Backpacker Mak-Cass. Yesterday I took the multi-mount off its tabletop base and put it on my Manfrotto tripod for some digiscoping. I was using it without the power on, as a manually-aimed alt-az mount.

Another of those down-the-tube shots showing the optics. The point of this photo is different, though. Check out the knurled knob on the left that tightens the dovetail. Usually these just have a fat set-screw that goes straight onto the scope’s dovetail bar, and tightening that screw puts a tiny dent or ‘bite’ into the dovetail bar. On this mount, though, the set-screw bypasses the scope’s dovetail bar, and turning the hand knob tightens a broad metal clamp (the silver bit just underneath the hand knob in the above photo) that grips the dovetail bar along its entire length. So the scope is held more securely, and there’s no bite mark on the dovetail bar. Very nifty–I wish more mounts had this.

The big news about using the mount manually is simply that it can be used that way. You don’t want to manually aim the scope once the power is on, or you risk damaging the gears inside the mount, but as long as the power is off you can just grab the tube and point.

A close-up of the back end showing, from left to right, the Astro-Tech dielectric diagonal and 32mm Plossl I was using for birding, the six-screw  mount for the little 8×20 optical finder, and the dovetail clamp and adjacent latitude/altitude scale on the mount.

Getting lined up on a distant bird using the optical finderscope. Imagine that the mount was sitting on its tabletop base and that you were trying to find something high in the sky–eventually there is just no room to get your head behind the eyepiece of the finder. That’s why I strongly prefer RACI–right angle, correct image–finders, which orient the finder eyepiece in the same direction as the telescope eyepiece, so you can look down and in from above.

Waiting for the fall of night.

My two best shots of Jupiter with the little Mak. I could see about half a dozen distinct cloud bands at the eyepiece, and for once the photos bear that out. As usual, however, I could still see more detail at the eyepiece than the camera captured. The views are not as good as through the Apex 127–compare to the Jupiter photo here–but they’re not that far behind.

The waxing gibbous moon, again with the little Mak. This is probably the sharpest moon photo I’ve ever gotten with a 90mm Mak. This SkyWatcher scope is at least as good, optically, as the Orion Apex 90 I used to have. I don’t know yet if it’s as good as the Celestron C90, which has gotten stupid-good reviews, but I don’t think it will disappoint anyone. Last night the sky was still enough that I could run it up to 200x and the view was still razor-sharp. That’s 57x per inch of aperture, compared to the rough rule of thumb of 50x/inch in a good scope, so this little scope is punching above its weight. I haven’t tried to max out the magnification to see where it breaks down, but I think it will probably be quite a bit higher.

The fact that the meniscus is merely coated instead of multi-coated has not impaired the scope’s performance as far as I can tell. Possibly the few percent difference in light transmission will be noticeable when one can switch back and forth between this scope and one with a multi-coated meniscus; it is certainly not noticeable when using the scope on its own.

I still haven’t had time to try out the tracking function on the mount, but this afternoon I did put batteries in and slewed it around and didn’t have any problems. I’ll report back when I’ve had it out tracking under the stars.


The moon, Venus, and Jupiter, as promised

February 26, 2012

A followup from a recent post. Here’s how the celestial trio looked from my driveway last night. Venus is lowest and Jupiter is highest. No scope for this shot, just my old Nikon Coolpix 4500 on a tripod, about a 1 second exposure. The CCD is a little noisy at that length, especially in low light, so the picture is more pixellated than I’d like, but it’ll do.

Here’s a closeup of Venus and the moon, shot through my SV-50 and a 32mm Plossl (7x), unzoomed.

Tonight the moon is up by Jupiter, and even closer to the King of Planets than it was to Venus last night. I got a quick naked-eye look as we were off to dinner tonight, but by the time we were done eating, the clouds had rolled in, the moon was just a bright fuzzy spot in the sky, and the planets were completely obscured. So it goes.

Next month Venus will be even higher in the sky and Jupiter will be a little lower, so the two will be even closer and prettier when the moon visits them next. Even when the moon is elsewhere, the two planets reward study with the naked eye, binoculars, and telescopes. Mars is up in the east right after sunset, as close to Earth as it will get for the next couple of years, and Saturn is rising around midnight for the night-owls. It’s a good time to observe the planets. Even if all you have time for is a naked-eye peek, you can still appreciate that these moving lights in the sky–“planet” is Greek for “wanderer”–are worlds, that we know something about them, and that someday–maybe–we’ll go out there and explore them ourselves.


Don’t miss the moon and planets at sunset this weekend

February 25, 2012

From bottom to top: the moon, Venus, and Jupiter, on Feb. 24, 2012.

Venus and Jupiter are both high in the evening sky at sunset right now. Just look west right when it gets dark and they’ll be the two brightest stars in the west. Venus is the brighter and lower of the two.

For the next couple of nights they’ll be joined by the waxing crescent moon. Tonight the moon was just below Venus, so the three bodies were stacked up the sky from lowest and brightest to highest and dimmest.

Early next week the moon will pull away from the planets as it continues on its monthly eastward trek around the sky, but Venus and Jupiter will still be there and looking good.

A close-up of the moon at the same time as the photo at top.

Venus is slightly gibbous right now (between 4 and 5 in the diagram below). On March 26 it will achieve its greatest eastern elongation from the sun, 46 degrees, meaning that at sunset it will be halfway between the horizon and the zenith. At that point it will be half-lit as seen from Earth (5). From then on into April and May, Venus will get lower and larger as it goes into its crescent phase (6) and gets ready to pass between the Sun and the Earth. Venus makes that passage all the time as it transitions from being the evening star (east of the sun as seen from Earth = above the western horizon at sunset, 6 in the diagram) to the morning star (west of the sun as seen from Earth = above the eastern horizon at sunrise, 1 in the diagram).

Phases of Venus as seen from Earth

Because the orbits of Earth and Venus are not precisely in the same plane, Venus does not usually pass directly between the sun and the Earth but passes above or below the sun as seen from Earth. This time will be different; as happens only a couple of times per century at most, the orbits are lined up just so and Venus will pass across the face of the sun as seen from Earth. That’s the transit of Venus I’ve been so het up about. Stay tuned for more on that, and keep looking up at sunset for the next few weeks to see Jupiter and Venus continue their tango.


The mountains of the moon, and the moons of Jupiter

February 15, 2012

My latest efforts at white-trash astrophotography (or, if you prefer, afocal projection photography, or digiscoping), wherein I hold my digital camera up to the eyepiece of my telescope and take pictures:

The moon last night, at last quarter. I love this phase because the mountains that form the eastern rim of Mare Imbrium–the immense incomplete circle in the moon’s northern hemisphere–are still catching the light of the setting sun, creating an arc of light in a sea of darkness. Galileo saw the same thing with his 1-inch telescope 403 years ago, and correctly inferred that the lights in the darkness were mountaintops on the moon, catching either the first (when waxing) or last (when waning) rays of the sun, and that therefore the moon was not a perfectly smooth sphere, but a world with similarities to our own.

And, hey, it looks pretty. I like how the arc-of-light-in-darkness motif is repeated by the smaller craters along the terminator to the south of Mare Imbrium.

Jupiter and the Galilean moons, tonight. As with previous efforts (see here and here), this is a composite shot. To get the moons to show up at all, I had to completely overexpose Jupiter,  so this is a combination of two images. The order of the moons from right to left is also, by chance tonight, their order from closest in to farthest out from Jupiter: Io (by itself on the right), Europa, Ganymede, and Callisto. This is only the second time I’ve gotten Jupiter and all four kids in one shot; often one of the little bleepers is off in Jupiter’s shadow.

All photos taken with a Nikon Coolpix 4500 digital camera, Orion Apex 127mm Maksutov-Cassegrain telescope, and Orion Sirius Plossl eyepieces (32 mm for moon, 25 mm for Jupiter and family).


Cosmic triple play: the moon, Jupiter, and Uranus tonight

December 12, 2010

The not-quite first quarter moon will zip past Jupiter and Uranus tonight (that is, Monday night, Dec. 13). Here’s the view in Stellarium at about 6:00 PM, Pacific time, looking high in the south:

The moon and Jupiter are the easiest naked-eye objects in the skies right now. Grab some binoculars–any binoculars–to see moon craters, the moons of Jupiter, and Uranus, which will appear as a bright star just above and left of Jupiter (or north and east, if you prefer). It’s not the only reasonably bright ‘star’ in the field, so here’s a more printer-friendly map to take along:

Note the nearby stars K and 9 Piscium (so named because they are in the constellation Pisces, the fish). They make a visual double but not a gravitational one, which means that they are accidentally aligned as seen from Earth. K is brighter mostly because it is closer, only 162 light years away compared to 9’s 400-plus.

All of those are easy binocular targets. In a small telescope, the view only gets better: hundreds or thousands of craters and other lunar features are visible, as well as cloud belts on Jupiter, and Uranus may show up as a small blue-green disc instead of a mere point if you crank the magnification.

But it will be worth taking a moment to see even if all you observe with are a couple of Mark 1 eyeballs. Go have fun!


Observing report: the backup star party

October 11, 2010

Saturday afternoon London and I drove to the Mojave Desert east of Barstow, California. We caravanned with our friends Jann and Gene, whom Vicki and I have known since before London was born. The San Bernardino Amateur Astronomers, Pomona Valley Amateur Astronomers, and High Desert Astronomical Society were all coming together for a big star party at Afton Canyon. We missed that; the road down into the canyon had a few rocks big enough to potentially eviscerate my Mazda5 and Jann’s and Gene’s Honda Fit, so we camped up on the canyon rim. In the photo above, you can see some white picnic shelters down in the canyon.

As it turned out, we had a fabulous evening even though we missed the official star party. We were just getting set up before dark when a sedan pulled up next to us, which turned out to hold my friend and fellow PVAA member, Gary, and his 13″ Coulter dobsonian. I had my 10″ Orion dob and a 5″ widefield reflector a tripod, and Gene had brought along his Celestron C90, so we had plenty of telescopes. This would prove fortuitous. We had just a few minutes to catch the very young crescent moon before it set, and then ate dinner while we waited for twilight to fade.

Jupiter and the Galilean moons, taken with my XT10 and Nikon Coolpix 4500. Click for the big, unlabeled version.

A group of a dozen or so college students from USC were also camping on the canyon rim, fifty yards or so away from us. As I usually do when either camping or observing, I invited them to come over and stargaze if they were so inclined. Many of them took me up on the offer and from 7:00 until about 11:00 we–that is, Jann, Gene, Gary, and I–entertained a steady stream of guests. I had a low-power eyepiece in the 5″ reflector for widefield views of the Double Cluster, Andromeda Galaxy, Pleiades, and other expansive targets. Gene’s Mak was turning in tack-sharp views of Jupiter and some double stars, and Gary and I were serving up deep-sky objects with the two big dobs, with frequent breaks to watch the dance of Jupiter’s moons. I didn’t keep a list of things we observed, but off the top of my head I recall seeing, in addition to the aforementioned targets:

  • M7 and M6, open clusters between the tail of Scorpio and the teapot of Sagittarius;
  • M8, the Lagoon Nebula, and M20, the Trifid Nebula, in Sagittarius;
  • the M24 star cloud;
  • M11, the Wild Duck Cluster. This was a sure crowd-pleaser.
  • Ditto for M13, the Great Globular Cluster in Hercules;
  • More globs: M22 in Sagittarius and M15 off the nose of Pegasus;
  • Planetary nebulae: the Ring (M57), the Dumbbell (M27), and the Cat’s Eye (NGC 6543);
  • NGC 253, the Silver Coin Galaxy;
  • NGC 457, the ET Cluster, in Cassiopeia;
  • Brocchi’s Coathanger, an asterism near Cygnus;
  • Mizar & Alcor, a multiple star in the handle of the Big Dipper;
  • Epsilon Lyrae, the “Double Double” star, Lyra.

These were just the things we had in regular rotation. I also had my green laser pointer and was using it to point out the constellations and some of the brighter deep-sky objects. M7, M8, M20, the Andromeda Galaxy (M31), the Double Cluster, and Brocchi’s Coathanger were naked eye visible. It was also a cinch to get people on target with binoculars by pointing with the laser and letting them follow the beam. I had along three pairs of binoculars, 7×35, 7×50, and15x70, and they all got used.

We were seeing shooting stars throughout the evening, and I saw two that produced visible flames and left glowing trails across the sky. The sky, by the way, was very dark and very clear, probably the finest sky I’ve had for a big-scope observing session. The Milky Way was amazingly detailed to the naked eye even before the sunset had completely faded.

The group observing wound down sometime around midnight. Our last few targets included nebulae in and around Orion–M42, M43, and the sometimes elusive M78–and the galaxy pair of M81 and M82. By that point I was tired of driving the big scope and also just plain tired, so for my last hour of observing I curled up in a camp chair with the 5″ reflector and just did some casual solo stargazing, with no plan or fixed destination.

My favorite views of the evening were:

Number 3: seeing riffled edges on Jupiter’s cloud belts (the photo above does not do it justice), in the big scopes.

Number 2: seeing the Double Cluster surrounded by an incredibly rich Milky Way starfield, in the 5″ widefield scope. I prefer to observe the Double Cluster with a wide enough field to get some nicely frame the two dense conglomerations of stars and to give some context. Prior to Saturday night, my all-time favorite view had been with 15×70 binoculars from Mount Baldy. The view in the 5″ scope was like binoculars on steroids–a nice wide field, but packed with wall-to-wall stars. I got that sensation, which I crave, of having so many stars in the eyepiece that it was almost exhausting to take it all in.

Number 1: dust lanes in the spiral arms of M31. I first saw these for myself a couple of months ago out at Owl Canyon. Now that I know what to look for–and since I keep going to progressively darker sites!–these get easier and easier to spot. To me, it looks like someone got charcoal on their hands and dragged two fingers across the galaxy. The arms don’t show up as denser concentrations of light, but interruptions in the soft glow of the galaxy; not brighter but darker. I could see these in the 5″ scope, and they were sufficiently clear in the 10″ scope that people with no prior observing experience were seeing them right away. I remember how much of a kick in the brainpan it was when I first saw those spiral arms, and it was awesome to get to share that with others.

In fact, having people to share the views with really made the night. If it had just been Jann and Gene, Gary, and London and me, I’m sure we would have had a nice time. But it was so much nicer to have interested people stopping by to show things to. I’d say that my enjoyment of telescope time scales directly with the number of people I get to observe with. I can have a fine time all by myself, and it only gets better from there.

Stargazing was only half of the fun, though. This morning we had a lazy  breakfast in camp while we waited for the air to warm up a little, and then we went for a hike.

Gene had a GPS unit and the coordinates of a geocache, which gave us a general direction for the hike and an achievable goal. We followed the road down into Afton Canyon, crossed a dry riverbed under a railroad trestle bridge, and explored a very beautiful side canyon.

Eventually our first route led us to a treacherous slope so we found another way back down to the bridge. We found a stand of rushes and a trickle of water, with lots of dragonflies zooming around. Jann had a field guide to dragonflies along, so she and London watched dragonflies while Gene and I pushed on to the cache. Gene’s GPS  was getting satellite bounce that imparted some meandering to our path. At one point we found some old graves made of piles of rock with weathered, sunblasted wooden crosses, like something right out of the Old West. That was downright creepy, even for someone who works with cadavers. Eventually we did find the cache and sign the logbook, and all four of us enjoyed a leisurely stroll back to camp.

I’ve been fortunate to get out to the desert quite a bit this year–to the Salton Sea on several occasions in the spring, to Owl Canyon a couple of times, and to Joshua Tree Lake last weekend. This weekend’s trip was my favorite so far; the entire time I was exultant at being out at such a beautiful place. I’m already looking forward to next time.


Observing Report: Saturday night at Owl Canyon

September 6, 2010

Owl Canyon Campground is a few miles north of Barstow, in the Mojave Desert on BLM land. There are picnic tables, shelters, fire pits, and restrooms but no running water, and if you spend the night you’re supposed to leave your camping fee–all of six bucks–in a metal can on a post near the entrance. It’s almost exactly 90 miles from my house, on the other side of the San Gabriel Mountains. Although the Dark  Sky Finder puts the campground on the border between the green and blue zones, to my light-pollution-conditioned eyes, it is pretty darned dark out there. I was there observing from a little before 9:00 PM Saturday night until about 5:00 AM Sunday morning.

I set up my 10″ scope and took a quick turn around the sky, hitting the best and brightest clusters, nebulae, and galaxies. M51, the Whirlpool Galaxy, showed spiral structure. I saw not one but two dark lanes in M31, the Andromeda Galaxy. M27, the Dumbbell Nebula, looked more like a football wearing a bowtie, so extended was the nebulosity.

I had seen some of these things before, in larger telescopes, but they were all first-time observations for me, using my own telescope. And the night was just beginning.

Taking a break from the telescope, I pulled out my 15×70 binoculars just to see what I could see. And what I could see was incredible. The Milky Way was a wide, detailed arch of pale light stretching across the sky, so rich that I found star clusters and nebulae far faster than I could log or identify or even count them. I saw the North American Nebula, which really does look strikingly like North America, for the first time. Buoyed by that success, I went after the Veil Nebula, a double arc of wispy light expanding out from an ancient supernova. It was there, not bright, but unmistakably present. Later, using the telescope, I saw in the Veil the riffles of detail that I had previously seen only in long-exposure astrophotos.

I didn’t see all this at once, of course. After about 5 minutes of cruising the sky with binoculars, I realized that I was going to need a more extended, more comfortable look. I put a blanket and pillow on an empty picnic table, stretched supine, and spent the next two hours just looking up in wonder, much of the time with my naked eyes alone.

Lying up on the picnic table, my immediate surroundings were out of even my peripheral vision. The dome of the sky came down on all sides to the mountains, bluffs, and buttes that ring the campground on all sides. I was, therefore, alone beneath the cosmos, on a rocky world of my own.

There are about two dozen campsites at Owl Canyon. Saturday night, only three others were occupied, and none of them were close to me. But as usual when observing at a public campground, after setting up I had walked to the two inhabited sites I could conveniently reach (the third was across a minor canyon) and let the people there know that I had set up a telescope and that they were welcome, but certainly not obligated, to drop by for some stargazing. For the first time ever, I got no takers.

To be out there in that fantastic place, seeing such spectacularly evocative and beautiful things, and to have no one with whom to share them, was almost unbearable. I felt embarrassingly wealthy, like someone devouring a feast while his neighbors on either side go hungry.

About midnight I got down off the table, went back to the scope, and started on my planned observing program. Whether this reflects dedication, more focused curiosity, or a species of retreat from the terrible immensity which I had recently been contemplating, even I am not sure. You are welcome to perform the experiment yourself and report back. In fact, I strongly recommend it.

At some point I knocked off to take some photos of Jupiter, which by the early morning hours was almost halfway across the sky and the brightest single source of light I could see. I got some pictures, but the Great Red Spot was not in evidence. Fortunately Jupiter rotates quickly, once every 9 hours, so I had a feeling that I would catch the spot if only I was patient. I went back to the deep sky.

About 4:00 AM I was working the northern sky when I saw a most arresting site: an immense pale dome rising like a puffball mushroom behind a mountain to the east. This was of course the moon, but I had never before watched the waning crescent moon rise, and certainly not from a site as dark as this. The waning crescent moon leads the sun; the illuminated part is of course sun-wards, so the “dark” part is to the west and rises first. And this is what I saw coming up over the mountain: not the thin sliver of the moon illuminated by the sun, but the rest of the disc lit only by Earthshine. By the time I got the scope pointed in the right direction and the camera properly set, the bright “horns” of the sunlit moon were over the horizon, but the summit of the mountain still took a bite out of the disc.

By this point I had been awake for almost 20 hours and observing for more than 7, and I was starting to wind down. But I went back to Jupiter for one last look, and sure enough, the Great Red Spot was there. And above the GRS was a little black BB: the shadow of a moon crossing the face of the King of Planets. The visible moons from left to right in this shot are Europa, Ganymede, and Callisto. Io is invisible in front of Jupiter, at least through my telescope, but it is the one casting the shadow.

After Jupiter I crawled into the car, slept for 3 hours, and then drove into Barstow to the hotel where Vicki  and London were staying. The next night I drove them a couple of miles out of town and showed them the Milky Way. And now… now all I want is for the next few weeks to pass quickly, and for the next dark of the moon to find me once again in the desert, under beautifully dark skies, staring up in wonder.


The unrestrained Jupiter worship has got to stop

September 3, 2010

In a comment on the recent Jupiter impact post, Mike asked,

Uh. If this [i.e., big things slamming into Jupiter] is happening to Jupiter three times in thirteen months, what does that tell us about the odds of it happening to us?

The answer is that Jupiter giveth, and Jupiter taketh away.

In my experience, about 99% of the popular sources out there only mention the second, positive part: Jupiter is the solar system’s vacuum cleaner, hoovering up tons of wayward comets and other “small bodies” (all the way down to mere dinosaur killers) that would otherwise bomb us back into the Paleocene. The spate of recent impacts would tend to confirm that. Three cheers for Jupiter! Our hero! Let’s have a ticker tape parade!


Can we all take the Jupiter worship down a couple thousand percent? Because that ain’t the whole simple story. Jupiter also giveth, and what it giveth, we don’t wanteth.

Ever wonder why there are so many Earth-crossing asteroids?  I mean, the solar system has been here for close to 5 billion years. Shouldn’t the space rocks have hit something or gotten shot out of the system by now? In fact, the vast majority of them have. Earth-crossing asteroids have orbits that are stable on multi-million year timescales… which means that on the multi-billion year timescale of the solar system, they should be history. But they’re not, because new ones keep migrating in from the asteroid belt all the time, to replenish the ones that either get flung elsewhere or (gulp) hit us. And why do new asteroids keep coming in from the belt? Because of orbital resonances with stinkin’ Jupiter. That big bully keeps throwing rocks at us!

Now, it’s true that most near-Earth asteroids are destined to either spiral on it toward the Sun or get flung out of the inner solar system, and that only a very small fraction actually hit the Earth. And it’s also true that Jupiter sucks up a lot of comets and asteroids that might otherwise come in and hit us, and that the occasional impact damage from Earth-crossing asteroids is probably preferable to getting creamed by an unfettered rain of comets barreling in from the outer solar system. So on the balance, we’re better off with Jupiter than without. Jupiter is like that one tough guy among your childhood friends, who would keep other groups of kids from hassling your group, but might punch you really hard in the shoulder once a while, for no apparent reason.

So let’s lay off with the fawning science news coverage and virgin sacrifices. Jupiter is nice to have around, but it is nowhere near 100% cool.


In other news, I took the shot at the top from my driveway the other night, shooting with a Nikon Coolpix 4500 through an Orion XT12i telescope and 13mm Stratus eyepiece. The moons from left to right are Ganymede, Io, and Europa. I could see Callisto off to the right as well, but it was out of this shot.