New Horizons In The Asteroid Belt, Summer - Autumn 2006 Options

[Greg Hullender]

Although note that the way the "Where Is New Horizons Now" page is drawn, it looks as though the asteroid belt extends right up to the orbit of Jupiter.

http://pluto.jhuapl.edu/mission/whereis_nh.php

[Toma B]

Although note that the way the "Where Is New Horizons Now" page is drawn, it looks as though the asteroid belt extends right up to the orbit of Jupiter.

Why?
How it should be drawn?
I don't get it...

[ugordan]

I think Greg is mistaking those white pixels as asteroids. These are apparently stars brighter than magnitude 12. They aren't very convincing, though -- no brightness variation, no nothing... What's the FOV of these projections supposed to be, without it the starfield has no meaning?

[Rob Pinnegar]

If those are stars of magnitude 12 or brighter the FOV has to be miniscule -- miniscule enough that the starfield wouldn't have any meaning regardless of whether stars of different magnitude were given different symbols.

There's not much chance that any of the stars depicted there are bright enough to be seen without binoculars or a telescope. Remember that the density of stars goes up exponentially with increasing magnitude; I don't remember the exact relation, but that's the long and short of it. Just from a statistical standpoint it's unlikely anything there is brighter than maybe magnitude 9 or so.

An FOV wide enough to show recognizable constellations would be so jam-packed with dots representing 12th-magnitude stars that you wouldn't be able to see anything else. My guess is that this view is from a few thousand AUs out -- which would minimize perspective effects.

[Greg Hullender]

I think ugordon is right. I just didn't look closely enough -- otherwise I should have complained that there were too many "asteroids" inside the orbit of Earth!

Sorry about that . . .

--Greg

[punkboi]

??

Um... You didn't know those were stars? Just wondering

[Greg Hullender]

??

Um... You didn't know those were stars? Just wondering

Well, I love checking those things for the various probes, so I do know they're stars, but for this one I guess I had "asteroid belt" so firmly in my mind that that's what I saw in there.

As John Kennedy said, "Some people see things that are and say, 'huh?' I see things that aren't there and say 'oh wow!'"

--Greg (Well, almost) :-)

[Guest_AlexBlackwell_*]

Pluto-Bound Camera Sees 'First Light'
New Horizons Payload Fully Operational as Telescopic Imager Glimpses Star Cluster
For Immediate Release
September 1, 2006
http://pluto.jhuapl.edu/news_center/news/090106.html

[RNeuhaus]

This is a very important milestone since it is the first time that all 7 instruments start to operate fully, that is about almost after 8 months of dormant trip. At least all of them are in good conditions.

Rodolfo

[alan]

How dare you bump the New Horizon thread above the Pluto is / is not a planet discussion

[Jeff7]

Well if you'll note, the category is called "Pluto/KBO". It's lumped right in there with the other KBO's anyway, so it seems the decision has inadvertently been made already, eh? mHMMMMM?


Good to know that NH is in good shape. Hopefully it doesn't accumulate too much dust and who-knows-what-else on the lens like Cassini did. It's sure got a long trip ahead of it.

To those who are arguing about Pluto's planetness - hey, it's still got its very own probe headed to it no matter what we call it. That's got to count for something. Planet or not, I'm definitely going to be looking out for the data as it arrives from way the heck out there.
I still just love the look of the probe too - it looks like a huge antenna that just happens to be bringing an instrument pack along for the ride.

[Comga]

If those are stars of magnitude 12 or brighter the FOV has to be miniscule -- miniscule enough that the starfield wouldn't have any meaning regardless of whether stars of different magnitude were given different symbols.

From http://nssdc.gsfc.nasa.gov/database/Master...6-001A&ex=1

The New Horizons Long Range Reconnaissance Imager (LORRI) is a panchromatic narrow angle imager. .... It consists of a 20.8 cm aperture telescope which focuses visible light on a 1024 x 1024 pixel CCD. There are no filters or moving parts. The instrument has a 5.06 x 5.06 milliradian field of view with a resolution of 0.00494 milliradians/pixel.

Also available at http://pluto.jhuapl.edu/spacecraft/instruments.html

and from http://www.boulder.swri.edu/~layoung/proje...nitude%22%20%22

LORRI limiting magnitude requirement, 4x4 binned. mode, 9.9 sec exposure is V = 17.4.

5 mrad is a little under 1/3 of a degree, or 2/3 the diameter of our Moon in the sky. Given that it can make 10 sec exlposures and see stars down to 17th magnitude, there are an enormous range of star clusters it can see.

[Guest_PhilCo126_*]

So we can conclude this topic by stating that the New Horizons flew through the asteroid belt between May and August 2006