Enjoying Jupiter through new eyes

After a couple of weeks of wild weather, including snow, ice storms, high wind, and heavy rain, the greater Seattle area is enjoying something most unusual: a clear, calm winter night.

Jupiter doesn't look quite like this through my backyard telescope,
but a Tele Vue Radian eyepiece is giving better views than
I've ever had before. Cassini snapped this one on its way to
Saturn in 2000. Photo: NASA.

The timing is both right on and a bit off for astronomy buffs in the area. At nightfall the Moon was pleasantly centered between Venus and Jupiter, making for a picture postcard view. However several area astronomy clubs have their monthly public star parties scheduled for Saturday evening, and the forecast is for the clouds to move back in after our brief respite from precipitation.

I took advantage of the clear night to haul my telescope out of the basement and take a look. I had a peek at the gibbous Venus, and looked at the crescent Moon for a bit. But I have been watching Jupiter for most of the evening. I find the clockwork of old Jove’s moons endlessly fascinating. Io was in transit across the giant planet’s disk between about 7 p.m. and 9:15. Io’s shadow is following about an hour and 15 minutes behind, and will complete its transit of Jupiter at around 10:30.

I’ve got to throw in a plug for a relatively new eyepiece in my case. Last year right after Christmas I used some gift cash (thanks, Mom!) to buy a 10mm Tele Vue Radian. Using it to look at Jupiter this evening made me feel as though the scales had fallen from my eyes and I was seeing the planet for the first time!

I have an 8-inch “Intelliscope” from Orion, and it’s pretty much as it came out of the box (though my aching neck convinced me to replace the straight-through finderscope with a right-angle model, and I added a Telrad finder, which is pretty useless from my West Seattle backyard observing location, given the few bright objects that can be seen through the thing.) My high-power eyepiece had always been the 10mm Sirius Plossl that came with the scope. It’s OK, but has minimal eye relief. I typically found that I got much better views from a 17mm Plossl and a 2x Barlow.

Then I sprung for the Radian. Wow. I got some eye-popping views of Saturn through it earlier this year, but looking at Jupiter with its detailed bands, zones, and clouds, the difference a top-quality eyepiece can make is readily apparent. Even in transit, Io was easy to spot. The Red Spot stood out clearly, and though seeing has not been all that transparent this evening, in moments of clarity I’ve seen detail on Jupiter tonight that I’ve never seen under the best of conditions before. The Radian set me back about $235.

By the way, Tele Vue has discontinued the 10mm Radian and some are speculating they’ll drop the line entirely in favor of the new Delos line that came out in the middle of last year. They have the same eye relief but a wider field of view. I’m really impressed with the Radian. I have one other Tele Vue eyepiece, a 24mm Panoptic, and it, too, is marvelous, offering tremendous, wide-field views. They’re on the pricey side, but well worth it for the quality views they deliver.

What are your favorite eyepieces?

Alas, as I’m wrapping up this post at about 11 p.m. Friday the clouds have indeed rolled in. I had planned to get back out there. I’m working on the Astronomical League Urban Observing program, and one of the last items I need to spot is NGC 3242—The Ghost of Jupiter. It’s a planetary nebula that’s only visible around here from about now until early spring. We don’t get enough clear nights this, or any, time of year. NGC 3242 transits a little after 2 a.m. Saturday. It looks like it will do so behind the clouds and the quest will have to wait for yet another night.

Let’s hope for some clearing for a peek at the Ghost of Jupiter, and for all of those clubs planning star parties for Saturday evening. Check our calendar for details about one near you.