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

[SFJCody]

Will there be any serendipitous asteroid passes?

[ugordan]

Will there be any serendipitous asteroid passes?

More importantly, will there be any such passes *after* the optical instruments are commissioned, several months after launch?

[john_s]

Will there be any serendipitous asteroid passes?

According to the latest tabulation, the closest approach to a known asteroid will be to the 2 km object 1999 JV26, which we pass on April 19th at a range of 1.3 million km. No asteroids will get bigger than 1.2 LORRI pixels.

[SFJCody]

According to the latest tabulation, the closest approach to a known asteroid will be to the 2 km object 1999 JV26, which we pass on April 19th at a range of 1.3 million km.  No asteroids will get bigger than 1.2 LORRI pixels.

Hmm... right on the inner edge of the belt.

[stevesliva]

I don't suppose NH will pass close enough to the the Lagrange point of Neptune to find any new Trojans?

[JRehling]

I don't suppose NH will pass close enough to the the Lagrange point of Neptune to find any new Trojans?

NH will certainly be well off the orbital plane by the time it has covered so much of the leg between Jupiter and Pluto. Even if the trajectory were perfect in two dimensions, it'll be off in that one.

[YesRushGen]

According to the latest tabulation, the closest approach to a known asteroid will be to the 2 km object 1999 JV26, which we pass on April 19th at a range of 1.3 million km. No asteroids will get bigger than 1.2 LORRI pixels.

Just as an excercise, I wonder what magnitude of deltaVs would be required to (a) place NH on a course for a close flyby of JV26 and (b) restore the Jovian aimpoint after the flyby.

best,

Kelly

[stevesliva]

As for being above the plane, yes, but my mind was basically wandering along the lines of:

If there is a sphere around NH in the outer solar system in which Lorri would substantially exceed the resolution of ground-based telescopes, does this sphere ever include interesting regions of space such as the langrange points of any gas giant...

But no doubt the field of view isn't large enough to really work well in surveying large regions of emptiness.

[punkboi]

According to Alan Stern in an interview on Planetary Radio, New Horizons will have a distant encounter with a Centaur in 2010.

[Guest_AlexBlackwell_*]

According to Alan Stern in an interview on Planetary Radio, New Horizons will have a distant encounter with a Centaur in 2010.

Yes, I have to say that that was a good interview with Alan.

[lyford]

If I heard right, that "encounter" will be at a distance of 2.5 to 2.8 AU... but what's a couple hundred million miles between friends? Still that's a lot closer than we are right now....

[stevesliva]

I don't suppose NH will pass close enough to the the Lagrange point of Neptune to find any new Trojans?

Apparently they *are* hoping for some Neptunian trojans to pop into view in 2014!
http://pluto.jhuapl.edu/overview/piPerspec..._5_1_2006_2.php

[Guest_PhilCo126_*]

Asteroid belt passage ... anyway no problem in the Kirkwood gaps

[Guido]

The Asteroid belt falls roughly between 2.06 and 3.27 AU (see http://en.wikipedia.org/wiki/Asteroid_belt )
As for today New Horizons is 2.24 AU from the sun, so already entered the Asteroid belt some time ago.
Still 1.03 AU to go. Assuming the flight path makes an angle of 45° with the orbits (from New Horizons Current Position http://pluto.jhuapl.edu/mission/whereis_nh.php ) means New Horzions has to travel another 1.46 AU before it leaves the Asteroid belt.
This means, at an average speed of 28.64 km/sec, another 88 days inside the belt. Till august 22nd.

[Guido]

See http://pluto.jhuapl.edu/news_center/news/081706.html

[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