New Horizons Jupiter Encounter |
New Horizons Jupiter Encounter |
Guest_AlexBlackwell_* |
Jan 10 2007, 09:47 PM
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#1
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Jan 24 2007, 09:30 PM
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#91
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Dublin Correspondent Group: Admin Posts: 1799 Joined: 28-March 05 From: Celbridge, Ireland Member No.: 220 |
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Jan 24 2007, 09:46 PM
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#92
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Member Group: Members Posts: 529 Joined: 19-February 05 Member No.: 173 |
Yes, we'll slow after Jupiter. See the Press Kit on the JHUAPL web site front page for the numbers.
As to V1 and V2 comparisons to NH, you'll have to scare those numbers up for yourself, I think. -Alan |
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Jan 24 2007, 10:35 PM
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#93
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I just asked Mark Showalter at the PDS Rings Node if they were going to incorporate New Horizons into their Jupiter viewer. Turns out they already have a separate New Horizons Jupiter Viewer and Ephemeris Generator, which I hadn't noticed before. The Viewer is very handy to get a prediction of how the planet, satellites, and rings will look to the ORS instruments at different times during the encounter. To get the field of view you want using the viewer:
LORRI's FOV is square at 1044 arcsec The slit of the Alice spectrometer is 14438 arcsec long (it's only 350 arcsec wide) MVIC panoramas are 20626 arcsec wide and whatever number they want long LEISA's FOV is square at 3280 arcsec. ...I think. I calculated these based on the FOV numbers given at http://pluto.jhuapl.edu/spacecraft/instruments.html. Have fun. --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jan 24 2007, 10:43 PM
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#94
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Senior Member Group: Admin Posts: 4763 Joined: 15-March 05 From: Glendale, AZ Member No.: 197 |
If someone would please invent a multicycle engine that can morph from turbofan to ramjet to scramjet to rocket then SSTO (and back) Well I'm real busy with the concrete walk and back patio these days, but I promise I'll have a look as soon as I'm done (probably May if we don't have too much rain this winter) ....unless of course Doug finishes the UMSF shed first, then maybe he'll have time. -------------------- If Occam had heard my theory, things would be very different now.
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Jan 25 2007, 12:19 AM
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#95
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Member Group: Members Posts: 701 Joined: 3-December 04 From: Boulder, Colorado, USA Member No.: 117 |
Here's a simplified and slightly updated version of the Jupiter observation timeline...
jupiter_timeline_static.xls ( 114.5K ) Number of downloads: 855 John. |
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Jan 25 2007, 10:21 AM
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#96
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
And new images added to the SOC gallery up to the 21st.
Doug |
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Jan 25 2007, 04:50 PM
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#97
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Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
Two satellites and two shadows !
First details visible on Ganimedes (or Callisto) -------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
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Jan 25 2007, 05:30 PM
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#98
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Senior Member Group: Moderator Posts: 3233 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Here is a rotation movie for January 21:
http://pirlwww.lpl.arizona.edu/~perry/New_...Jan21_movie.gif The moon that crosses that transits during the first half of the movie (and casts a shadow on Jupiter) is Europa, while Io makes a brief, one frame appearance. -------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Jan 25 2007, 11:41 PM
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#99
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Junior Member Group: Members Posts: 94 Joined: 22-March 06 Member No.: 722 |
Based on the approximate orbital velocity of Pluto at encounter, and the total relative velocity of NH and Pluto at encounter, I (awhile back) derived a velocity of ~12.7 km/s for NH at Pluto. Assuming that's correct, that puts NH well above the velocities of P10 and P11 (at 12.1 and 11.5 km/s, respectively), but far below either of the Voyagers (at 15.6 km/s for V2 and 17.1 km/s for V1).
For those a little more bored than I, one can calculate the "loss distance" of NH from P10 and P11, based on the difference in velocities. Lessee...NH will be moving at about 2.7 AU/yr. once she passes Pluto. That means she'll be gaining 1.2 AU/yr. relative to P11, and 0.6 AU/yr. relative to P10. That isn't as much as it sounds; if my numbers are right, NH won't catch up with P11 until ~2066 (at 138 AU), and not to P10 until ~2151 (at 367 AU). For the record, in 2066, the Voyagers will be at: V2: 250 AU V1: 286 AU In 2151: V2: 531 AU V1: 592 AU Feel free to check my figures, all. -------------------- Mayor: Er, Master Betty, what is the Evil Council's plan?
Master Betty: Nyah. Haha. It is EVIL, it is so EVIL. It is a bad, bad plan, which will hurt many... people... who are good. I think it's great that it's so bad. -Kung Pow: Enter the Fist |
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Jan 26 2007, 09:40 AM
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#100
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
Why do these NH images look somewhat blurrier than Cassini's comparable NAC frames? Does LORRI have a greater PSF? I'm judging by the sharpness of the moons' discs to be clear.
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Jan 26 2007, 10:24 AM
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#101
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
Got some side by side comparisons?
Doug |
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Jan 26 2007, 10:39 AM
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#102
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Senior Member Group: Members Posts: 3648 Joined: 1-October 05 From: Croatia Member No.: 523 |
Not at the moment, I'm at work, but I'll try to dig up some Cassini PDS ones for comparison later. It might be subjective, but I do get the feeling LORRI has a slightly wider PSF.
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Jan 26 2007, 11:02 AM
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#103
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
It may be true of course, and I think LORRI is a narrower FOV than either of the CICLOPS pair - but of course comparing JPGs with PDS IMG's isn't a true comparison.
Hopefully John or Alan will comment. Doug |
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Jan 26 2007, 05:18 PM
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#104
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Member Group: Members Posts: 701 Joined: 3-December 04 From: Boulder, Colorado, USA Member No.: 117 |
It's true, LORRI is a much smaller and simpler camera than the Cassini NAC, and the PSF isn't quite so sharp. The high-frequency information is there, however, and the images can be sharpened nicely (though with increased noise).
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Jan 26 2007, 05:36 PM
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#105
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
I read in "Calibration of the New Horizons Long-Range Reconnaissance Imager" by Morgan et al. that LORRI has "a PSF FWHM of 1.5 pixels with little variation across the FOV..."
PSF = Point Spread Function; FMHM = Full width at half maximum. And from the instrument info on the Cassini PDS disks: "The NAC point spread function (PSF) was designed to be approximately the same physical size as a pixel in the near-IR. The full width at half maximum (FWHM) of the PSFs of the NAC through the clear filters is 1.3 pixels." Why would the FWHM be wider through the clear filters than the IR? To compare the masses, the mass of both Cassini cameras is about 57.83 kg. Anyone have a guess as to what fraction of that the NAC makes up? LORRI is only 5.5 kg! --Emily -------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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