New Horizons: Approach Phase, OpsNav - 25 January 15 to 28 June 15 Options

[peter59]

It's incredible, from Pluto separates us only one astronomical unit !
The last nine years have passed so quickly, to meet with Pluto remained only a little over one hundred days.

[nprev]

Alan just announced on social media that the recent TCM was nominal.

[Habukaz]

Now, if I've understood this blogpost correctly and not made any mistakes, here should be all of the best-of-the-day (and best yet) non-binned NH images taken between 1 Februrary and 12 July with the corresponding estimated sizes of Pluto and Charon in pixels (as viewed with LORRI).

Using 2400 km as diameter for Pluto, 1207 km for Charon and rounding to nearest integer. Green marks the first non-binned imaging session that month.

01.02: 973 km/px - Pluto 2 pixels across, Charon 1 pixel

12.04: 551 km/px - Pluto 4 pixels across, Charon 2 pixels
13.04: 545 km/px - Pluto 4 pixels across, Charon 2 pixels
14.04: 539 km/px - Pluto 4 pixels across, Charon 2 pixels
15.04: 533 km/px - Pluto 5 pixels across, Charon 2 pixels
16.04: 528 km/px - Pluto 5 pixels across, Charon 2 pixels
17.04: 522 km/px - Pluto 5 pixels across, Charon 2 pixels
18.04: 516 km/px - Pluto 5 pixels across, Charon 2 pixels
19.04: 514 km/px - Pluto 5 pixels across, Charon 2 pixels

28.05: 281 km/px - Pluto 9 pixels across, Charon 4 pixels
29.05: 276 km/px - Pluto 9 pixels across, Charon 4 pixels
30.05: 269 km/px - Pluto 9 pixels across, Charon 4 pixels
31.05: 265 km/px - Pluto 9 pixels across, Charon 5 pixels

01.06: 258 km/px - Pluto 9 pixels across, Charon 5 pixels
02.06: 253 km/px - Pluto 9 pixels across, Charon 5 pixels
03.06: 242 km/px - Pluto 10 pixels across, Charon 5 pixels
05.06: 234 km/px - Pluto 10 pixels across, Charon 5 pixels
06.06: 229 km/px - Pluto 10 pixels across, Charon 5 pixels
07.06: 222 km/px - Pluto 11 pixels across, Charon 5 pixels
08.06: 217 km/px - Pluto 11 pixels across, Charon 6 pixels
09.06: 210 km/px - Pluto 11 pixels across, Charon 6 pixels
10.06: 205 km/px - Pluto 12 pixels across, Charon 6 pixels
11.06: 198 km/px - Pluto 12 pixels across, Charon 6 pixels
12.06: 193 km/px - Pluto 12 pixels across, Charon 6 pixels
13.06: 183 km/px - Pluto 13 pixels across, Charon 7 pixels
15.06: 174 km/px - Pluto 14 pixels across, Charon 7 pixels
16.06: 169 km/px - Pluto 14 pixels across, Charon 7 pixels
17.06: 162 km/px - Pluto 15 pixels across, Charon 7 pixels
18.06: 158 km/px - Pluto 15 pixels across, Charon 8 pixels
19.06: 151 km/px - Pluto 16 pixels across, Charon 8 pixels
20.06: 146 km/px - Pluto 16 pixels across, Charon 8 pixels
21.06: 139 km/px - Pluto 17 pixels across, Charon 9 pixels
22.06: 134 km/px - Pluto 18 pixels across, Charon 9 pixels
23.06: 122 km/px - Pluto 20 pixels across, Charon 10 pixels
25.06: 110 km/px - Pluto 22 pixels across, Charon 11 pixels
27.06: 98.4 km/px - Pluto 24 pixels across, Charon 12 pixels
29.06: 86.5 km/px - Pluto 28 pixels across, Charon 14 pixels

01.07: 74.7 km/px - Pluto 32 pixels across, Charon 16 pixels
03.07: 62.6 km/px - Pluto 38 pixels across, Charon 19 pixels
05.07: 50.9 km/px - Pluto 47 pixels across, Charon 24 pixels
07.07: 39.0 km/px - Pluto 62 pixels across, Charon 31 pixels
09.07: 27.1 km/px - Pluto 89 pixels across, Charon 45 pixels
11.07: 15.2 km/px - Pluto 158 pixels across, Charon 79 pixels
12.07: 12.7 km/px - Pluto 189 pixels across, Charon 96 pixels

[mcgyver]

Now, if I've understood this blogpost correctly and not made any mistakes, here should be all of the best-of-the-day (and best yet) non-binned NH images taken between 1 Februrary and 12 July with the corresponding estimated sizes of Pluto and Charon in pixels (as viewed with LORRI).

Using 2400 km as diameter for Pluto, 1207 km for Charon and rounding to nearest integer. Green marks the first non-binned imaging session that month.

12.04: 551 km/px - Pluto 4 pixels across, Charon 2 pixels
[...]
03.06: 242 km/px - Pluto 10 pixels across, Charon 5pixels

It is not very clear to me when the "Hubble limit" will be crossed: according to this blog post, the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to this page, at least 250 km/pixel resolution (pluto ~=10 pixel) can be reached by processing, obtaining these images:

http://www.nasa.gov/mission_pages/hubble/s...o-20100204.html

In first case, we would be currently crossing Hubble limit; in second case, we would be going to cross it in June.

Amazing achievements in both cases!

But we'll have to be patient:

* LORRI's detector is 1024 pixels square. Like many modern space cameras, when the camera reads out its detector, it digitizes each pixel as a 12-bit number. they can be zipped up to about 2.5 Megabits without any loss of detail. It takes 42 minutes to return one LORRI photo to Earth [on January 2015; on July/september, communication will be slower]
http://www.planetary.org/blogs/emily-lakda...to-is-hard.html

*There are few data downlinks near closest approach, so we will not receive many images in real time. But the ones we get will be great.
*The mission has promised to release LORRI images (higher-resolution, black-and-white) in near-real-time, but not MVIC (lower-resolution, color) images.
*Only 1% of the science data from the flyby will be returned to Earth during the period around closest approach, including images that the mission has selected for their high science value as well as high public interest. They will be releasing captioned and processed versions as fast as their small team can manage.
*The rest of the image data will be downlinked beginning in September, about 2 months after encounter. It will take 10 weeks to download the full data set.
[...]
On September 14, New Horizons will begin downlinking a "browse" version of the entire Pluto data set, in which all images will be lossily compressed. It will take about 10 weeks to get that data set to the ground. There will be compression artifacts, but we'll see the entire data set.
Then, around November 16, New Horizons will begin to downlink the entire science data set losslessly compressed. It will take a year to complete that process.

http://www.planetary.org/blogs/emily-lakda...pectations.html

[machi]

Resolution is given by diffraction limit which depends on telescope's main mirror diameter, wavelength of electromagnetic radiation and overall quality of optical system.
For past observations of Pluto by HST's FOC and ACS/HRC cameras resolution was between 610 (FOC in UV) and 1270 kilometers (HRC at 555 microns).

[Habukaz]

The official word is better than Hubble at some point in May.

https://twitter.com/NewHorizons2015/status/...766844947456000

[tedstryk]

It is not very clear to me when the "Hubble limit" will be crossed: according to this blog post, the Hubble limit is around 800 km/pixel and Pluto being 3 pixel large, but according to this page, at least 250 km/pixel resolution (pluto ~=10 pixel) can be reached by processing, obtaining these images:

McGyver, the difference is between super-resolution processing and the actual resolution of the camera. And since the ACS/HRC channel is long-dead, HST is no longer capable of mapping Pluto (other than hemispheric albedo differences).

[jgoldader]

IIRC, the image is actually renders of a mathematical model of the albedo distribution on Pluto's surface that was created to match the HST images, which only had a couple of resolution elements across Pluto, not an image constructed from super resolution.

Similar models were made based on the data from the Pluto-Charon mutual eclipses back in the... 80's and early 90's I believe it was. I worked on a different project with Dave Tholen, who authored the occultation papers with Mark Buie (there was an independent take on the eclipses by Binzel). The idea on those maps was to recreate the light curves of the mutual eclipses that were visible due to fortuitous alignment of the system. Charon, for example, would pass over different areas of Pluto's surface, and the brightness of the system would drop a lot if the area was bright, or only a little if the area was dark. Each eclipse basically gave a "cut" across Pluto's surface, and a lot of numerical modeling resulted in a map of Pluto's surface that would yield the observed light curves.

Really cool and clever stuff.

[Explorer1]

A pair of briefings coming up next week:

http://www.nasa.gov/press/2015/april/nasa-...ssion-to-pluto/

[Explorer1]

Presser on now: color images released!

http://www.nasa.gov/multimedia/nasatv/index.html

[alk3997]

First color New Horizon's image of Pluto/Charon:



http://pluto.jhuapl.edu/News-Center/News-A...p?page=20150414

First glance it looks like the lower part of the Pluto image is less red than the upper part. Perhaps that is just an artifact of the image processing or the solar angle?


Andy

[Explorer1]

I would be loath to make any interpretations; this still isn't BTH (Better Than Hubble), for now.

[Habukaz]

With MVIC, Pluto is currently...what, 1-2 pixels across?

[elakdawalla]

MVIC resolution in that image is 2274 km, just a bit under 1 Pluto diameter.

[Marvin]

Slightly larger version of the color image, found on Twitter:



Hubble did an amazing job resolving the color and brightness variations of the surface.

In a way, I feel sad. Before Pluto was mysterious, now it has a face. But I'm looking forward to the data to come.