Revisiting Jupiter's Moons at DVinfo.net

Chris Hurd · July 24th, 2006, 11:23 PM

I went back to Jupiter tonight. Not too hard to do as it's still the brightest "star" in the sky for the northern hemisphere and doesn't set until after midnight. This time I used the H1's stock 20x HD lens at maximum focal length, combined with the Canon 1.6x extender in back and a Century Optics 1.6x teleconverter in front.

So the focal length in 35mm terms is: 5.4mm x 20 x 1.6 x 1.6 x 7.2 = 1990.7mm (roughly).

Here are two shots... IMG 5310 was made without using a custom preset, and IMG 5312 was made with a specific custom preset. I've included crops to better show the differences between the two. And another image, so you can tell which moon is which, if you're into that stuff like I am. Be sure to click on 'em to view at their full size.

Both images were taken at f/5.2 at 1/4 sec. with 0db gain.

The preset settings? BGN -9, BRM -9, BGM -9. What a difference it makes!

Chris Hurd · July 24th, 2006, 11:27 PM

P.S. -- charting Jupiter's moons is easy when you have the app:

http://skyandtelescope.com/observing...cle_830_2.asp#

Greg Boston · July 25th, 2006, 01:01 AM

Chris, we've kicked around the idea of getting a good quality telescope to use up at Lake Texoma. There's too much light pollution here. What would be your recommendation?

-gb-

Chris Hurd · July 25th, 2006, 01:40 AM

Oh boy, don't get me started. It's kind of like choosing a guitar. Or a camcorder! Heh. I think the important thing for you is, will you leave it at the lake house or take it with you back and forth. If you're going to haul it around, then I'd suggest a medium-sized Schmidt-Cassegrainian, which is kind of a stubby little thing that's fairly transportable. They're a little more expensive but worth it.

If it's something you can leave in Texoma, then the same money will buy you the 3/4-ton extended-cab pickup of all telescopes, an eight-inch f/6 Newtonian reflector with a good German equatorial mount. Bigger, robust, not as delicate.

For real fun, build your own -- I did, twenty years ago. And it still works!

Here's a good place to start before going shopping: http://www.astronomy.com/asy/default.aspx?c=ss&id=9

Mike Teutsch · July 25th, 2006, 07:36 AM

Chris,

Does this mean you have an XLH1 now? Shots are cool!

Thought you guys would like the following info, which was sent to me by a friend. I keep it handy so as to remind me.

Mars is coming.

The Red Planet is about to be spectacular!

This month and next, Earth is catching up with Mars in an encounter that will culminate in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. Due to the way Jupiter's gravity tugs on Mars and perturbs its orbit, astronomers can only be
certain that Mars has not come this close to Earth in the Last 5,000 years, but it may be as long as 60,000 years before it happens again.

The encounter will culminate on August 27th when Mars comes to within 34,649,589 miles of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification

Mars will look as large as the full moon to the naked eye. Mars will be easy to spot. At the beginning of August it will rise in the east at 10p.m. and reach its azimuth at about 3 a.m.

By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30a.m. That's pretty
convenient to see something that no human being has seen in recorded history. So, mark your calendar at the beginning of August to see Mars grow
progressively brighter and brighter throughout the month. Share this with your children and grandchildren.

NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN

Chris Hurd · July 25th, 2006, 07:42 AM

Quote:

Originally Posted by Mike Teutsch

Mars will look as large as the full moon to the naked eye.

Oh wow, I sure hope not... we're all in serious trouble if it does!

Pete Bauer · July 25th, 2006, 08:48 AM

My mom sent me that exact same text a couple weeks ago, which is actually from the 2003 Mars-Earth close opposition. I assume that either out of innocent mistake, or perhaps to carry a trojan horse, someone has started this old info propagating on the 'net as if it applied to 2006. In point of fact, Mars will be on the opposite side of the sun from earth in Aug/Sep, at about 2.5 AU in August.

EDIT: For those interested, a smart guy at JPL has done this Java applet:
http://mars.jpl.nasa.gov/allabout/ni...marsearthorbit

Chris Hurd · July 25th, 2006, 09:05 AM

I had the good fortune to be in Yosemite National Park on a night on or around the 2003 Mars opposition, and the Mt. Diablo Observatory skywatcher's club had come down from the Bay area in force with a wide variety of scopes which they shared with the public. It was a wonderful sight to see Mars rising in dazzling red brilliance over Half Dome from a front row seat at Glacier Point; I'll never forget that experience. Here are a couple of shots from before sundown...

Mike Teutsch · July 25th, 2006, 09:15 AM

Quote:

Originally Posted by Pete Bauer

My mom sent me that exact same text a couple weeks ago, which is actually from the 2003 Mars-Earth close opposition. I assume that either out of innocent mistake, or perhaps to carry a trojan horse, someone has started this old info propagating on the 'net as if it applied to 2006. In point of fact, Mars will be on the opposite side of the sun from earth in Aug/Sep, at about 2.5 AU in August.

EDIT: For those interested, a smart guy at JPL has done this Java applet:
http://mars.jpl.nasa.gov/allabout/ni...marsearthorbit

Well, now I'm pis*ed! You might remove it so someone doesn't get fooled like I did. I hate it when people do that, I guess they are just trying to cause trouble and get attention for themselves.

Sorry-----Mike

Pete Bauer · July 25th, 2006, 12:49 PM

Unfortunately, that kind of thing is just part of the modern electronic landscape. Even within the military, I've seen where some Exec Officer or First Sergeant (and even once or twice a fairly high office within the Pentagon!) got spoofed by an "urban legend" sort of thing and sent out an unnecessary "APB" to hundreds or thousands of people. Then the emails REALLY start flying when the spoof gets challenged.

Ah well, we shrug our shoulders and carry on!

July 24th, 2006, 11:23 PM	#1
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Revisiting Jupiter's Moons I went back to Jupiter tonight. Not too hard to do as it's still the brightest "star" in the sky for the northern hemisphere and doesn't set until after midnight. This time I used the H1's stock 20x HD lens at maximum focal length, combined with the Canon 1.6x extender in back and a Century Optics 1.6x teleconverter in front. So the focal length in 35mm terms is: 5.4mm x 20 x 1.6 x 1.6 x 7.2 = 1990.7mm (roughly). Here are two shots... IMG 5310 was made without using a custom preset, and IMG 5312 was made with a specific custom preset. I've included crops to better show the differences between the two. And another image, so you can tell which moon is which, if you're into that stuff like I am. Be sure to click on 'em to view at their full size. Both images were taken at f/5.2 at 1/4 sec. with 0db gain. The preset settings? BGN -9, BRM -9, BGM -9. What a difference it makes! Attached Thumbnails __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 24th, 2006, 11:27 PM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	P.S. -- charting Jupiter's moons is easy when you have the app: http://skyandtelescope.com/observing...cle_830_2.asp# __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 25th, 2006, 01:40 AM	#4
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	Oh boy, don't get me started. It's kind of like choosing a guitar. Or a camcorder! Heh. I think the important thing for you is, will you leave it at the lake house or take it with you back and forth. If you're going to haul it around, then I'd suggest a medium-sized Schmidt-Cassegrainian, which is kind of a stubby little thing that's fairly transportable. They're a little more expensive but worth it. If it's something you can leave in Texoma, then the same money will buy you the 3/4-ton extended-cab pickup of all telescopes, an eight-inch f/6 Newtonian reflector with a good German equatorial mount. Bigger, robust, not as delicate. For real fun, build your own -- I did, twenty years ago. And it still works! Here's a good place to start before going shopping: http://www.astronomy.com/asy/default.aspx?c=ss&id=9 __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 25th, 2006, 07:36 AM	#5
Mike Teutsch Inner Circle Join Date: Oct 2004 Location: Port St. Lucie, Florida Posts: 2,614	Mars is coming!!!!!!!!!!!!! Chris, Does this mean you have an XLH1 now? Shots are cool! Thought you guys would like the following info, which was sent to me by a friend. I keep it handy so as to remind me. Mars is coming. The Red Planet is about to be spectacular! This month and next, Earth is catching up with Mars in an encounter that will culminate in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. Due to the way Jupiter's gravity tugs on Mars and perturbs its orbit, astronomers can only be certain that Mars has not come this close to Earth in the Last 5,000 years, but it may be as long as 60,000 years before it happens again. The encounter will culminate on August 27th when Mars comes to within 34,649,589 miles of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification Mars will look as large as the full moon to the naked eye. Mars will be easy to spot. At the beginning of August it will rise in the east at 10p.m. and reach its azimuth at about 3 a.m. By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30a.m. That's pretty convenient to see something that no human being has seen in recorded history. So, mark your calendar at the beginning of August to see Mars grow progressively brighter and brighter throughout the month. Share this with your children and grandchildren. NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN __________________ Chapter one, line one. The BH.

July 25th, 2006, 08:48 AM	#7
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	My mom sent me that exact same text a couple weeks ago, which is actually from the 2003 Mars-Earth close opposition. I assume that either out of innocent mistake, or perhaps to carry a trojan horse, someone has started this old info propagating on the 'net as if it applied to 2006. In point of fact, Mars will be on the opposite side of the sun from earth in Aug/Sep, at about 2.5 AU in August. EDIT: For those interested, a smart guy at JPL has done this Java applet: http://mars.jpl.nasa.gov/allabout/ni...marsearthorbit __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

July 25th, 2006, 01:01 AM	#3
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Chris, we've kicked around the idea of getting a good quality telescope to use up at Lake Texoma. There's too much light pollution here. What would be your recommendation? -gb-

July 25th, 2006, 09:05 AM	#8
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	I had the good fortune to be in Yosemite National Park on a night on or around the 2003 Mars opposition, and the Mt. Diablo Observatory skywatcher's club had come down from the Bay area in force with a wide variety of scopes which they shared with the public. It was a wonderful sight to see Mars rising in dazzling red brilliance over Half Dome from a front row seat at Glacier Point; I'll never forget that experience. Here are a couple of shots from before sundown... Attached Thumbnails __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

July 25th, 2006, 12:49 PM	#10
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	Unfortunately, that kind of thing is just part of the modern electronic landscape. Even within the military, I've seen where some Exec Officer or First Sergeant (and even once or twice a fairly high office within the Pentagon!) got spoofed by an "urban legend" sort of thing and sent out an unnecessary "APB" to hundreds or thousands of people. Then the emails REALLY start flying when the spoof gets challenged. Ah well, we shrug our shoulders and carry on! __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!