Will Pluto see a transit of Earth in about 6 years?

[PlutonianEmpire]

I was reading this:

http://news.yahoo.com/hubble-telesco...zQ5YTc-;_ylv=3

And I remembered from my first year or two using an open source space program several years ago, I was looking at the sun from Pluto, and saw Earth transit the sun at around July, 2018, although I don't know how accurate it might be. (The program I used was Celestia.)

So, will Earth really transit the sun as seen from Pluto in 2018?

[WayneFrancis]

I'm not sure what the point would be. The sun is just bright star at the distance of Pluto. You could hardly even resolve the disk of the sun with the naked eye at that distance.

[John Mendenhall]

I'm not sure what the point would be. The sun is just bright star at the distance of Pluto. You could hardly even resolve the disk of the sun with the naked eye at that distance.

But with a telescope . . .

[PlutonianEmpire]

But with a telescope . . .

That's why I posted.

Sadly, it's far too late now to send one...

I know New Horizons is on the way, but I don't know if it'll be able to see it.

[WayneFrancis]

If you are asking if there is an alignment maybe someone can confirm it or not. It would certainly be a rare event indeed given the orbital mechanics of it all. But beyond the fact that it is rare I believe there would be little point. We could, if we wanted to waste the money, send out a probe to 100 AU and watch Earth transit the sun about once a year...but again I'm not seeing the point.

Will there ever be an alignment? Yes. Will there be one in 6 years? I don't personally know but programs like celestia and other astronomical programs should easily be able to answer that question.

[Romanus]

It's possible; I'd use an online program like JPL's HORIZONS to see exactly when Pluto crosses the ecliptic. Given that transits of Earth from Neptune happen in yearly clusters around ecliptic passage, I'd even say it's likely, with the caveat that Pluto's orbit is much more inclined than Neptune's, and so is probably in the ecliptic plane for less time despite its slower orbit.

Note: Jupiter corrected to Neptune.

[grapes]

Pluto's orbit is highly inclined, and it takes 248 years to go around its orbit--but it is approaching the ecliptic, so six years from now may be right. The sun would be more than a minute across, so it'd be more than a point, but the earth would be a hundred times smaller.

[Barabino]

Pluto's orbit is highly inclined, and it takes 248 years to go around its orbit--but it is approaching the ecliptic, so six years from now may be right. The sun would be more than a minute across, so it'd be more than a point, but the earth would be a hundred times smaller.

[grapes]

It's more than a point in that illustration, right?

I assume that's supposed to be the surface of Pluto, with Charon on the horizon. Charon would be 7 times as wide and high as the moon appears to us. (2 x 603km radius/ 19,500km distance to Pluto center, about 3.5 degrees).

[frankuitaalst]

I was reading this:

http://news.yahoo.com/hubble-telesco...zQ5YTc-;_ylv=3

And I remembered from my first year or two using an open source space program several years ago, I was looking at the sun from Pluto, and saw Earth transit the sun at around July, 2018, although I don't know how accurate it might be. (The program I used was Celestia.)

So, will Earth really transit the sun as seen from Pluto in 2018?

I think Celestia is right . I've run my gravity simulator (using the Pluto-Charon Barycenter ) and found a transit of Earth in July 2018 . The transit takes about 10 hours .
What's more : about 2.5 years later Saturn will also see an Earth transit

[PlutonianEmpire]

I think Celestia is right . I've run my gravity simulator (using the Pluto-Charon Barycenter ) and found a transit of Earth in July 2018 . The transit takes about 10 hours .
What's more : about 2.5 years later Saturn will also see an Earth transit

I should mention that when I observed the transit in Celestia, I was using the default built-in "vsop87" orbit theory for the planets. Those who have the know how and know where to find better orbit data to put into Celestia may be able to make more precise observations.

[frankuitaalst]

I'm not aware of the accurancy Celestia gets , but it may be pretty good . The data Celestia generates even may come from the JPL data . See here :
http://ssd.jpl.nasa.gov/?planet_eph_export.
Here's a screenshot I got with my gravity simulator showing the Earth Moon transit viewed from Pluto .
Does is correspond with what you got with celestia?

[Globe199]

I think Celestia is right . I've run my gravity simulator (using the Pluto-Charon Barycenter ) and found a transit of Earth in July 2018 . The transit takes about 10 hours .
What's more : about 2.5 years later Saturn will also see an Earth transit

How did you do this? I'm really interested in finding transits of all planets from Pluto. There doesn't appear to be a schedule online anywhere.

[frankuitaalst]

Well , I wrote an integrator a while ago solving the N-body problem . The integrator uses an initial set of postions and velocities of all main bodies of the solar system I got from JPL . It's quite fast and accurate as it uses a 21 order interpolation formula known as the Taylor Method for solving differential equations . If you want I can run some other simulations for other planets . This doesn't take much time.

[Globe199]

Wow, interesting. I'd like to see a schedule of past and future transits from Pluto of inferior planets. Any other transits and occultations involving Pluto would be cool too.

[grapes]

A Taylor Method to order 21? That's pretty extreme!

How does it compare to results at smaller orders?

[frankuitaalst]

Well , the good point about the Taylor method is that one get's a taylor series in time with coefficients C0....Cn in position and velocity . Each coefficient tends to be smaller than its predecessor . So we get a converging series .
With order 21 I get an accurancy in position of about 1 meter for an iteration step of about 4 days which corresponds with 1/6 of the orbit ( in case of the moons orbit ) . For the Pluto's orbit this should be about 60 years in one iteration given an accurancy of 1 meter .
As a benefit one obtains the coefficients , so that an intermediate position , velocity, etc. can be easily calculated once the coefficients are stored . I guess JPL also stores the ephimerides in a series ( Chebyshev polynomials ? IARC ) .
The order 21 comes from the fact that empirically I've found that around this order the CPU time is minimized . Higher degrees don't give much additional benefit . Lower orders increase the CPU time to get the job done . Of course this may be dependent upon the compiler .

[frankuitaalst]

How did you do this? I'm really interested in finding transits of all planets from Pluto. There doesn't appear to be a schedule online anywhere.

Ran a short simulation for 500 years from now . For Jupiter up to Neptune there will not be a transit to Pluto . They don't even come close .

[grapes]

Pluto spends so much of its 248 year trip around the Sun high above the ecliptic--the only chance for a transit is around the short times when it is near the ecliptic. A planet like earth which makes a trip around every year has a greater chance of being caught in a transit than say Jupiter, that takes five years.

[Globe199]

Could we calculate how long Pluto spends "within" the ecliptic? That is, for how long is Pluto in a range that would even make transits possible? That could give us some clue as to the possibility of transits.

[frankuitaalst]

Pluto crosses the ecliptic two times every Plutonian year , so there is a chance of a transit about every 124 years .

[djellison]

A planet like earth which makes a trip around every year has a greater chance of being caught in a transit than say Jupiter, that takes five years.

Actually - that may not be true. Earth is small, and fast moving. Jupiter is large and moves slower. It may well be that as a percentage of its year, Jupiter takes longer to cross the surface of the sun as seen from the orbit of Pluto.

Now - that means that transits may be less frequent - but - at any given moment, it might be more likely that a Jupiter transit is occuring.

[Globe199]

Pluto crosses the ecliptic two times every Plutonian year , so there is a chance of a transit about every 124 years .

I'm guessing the chances are a little better than that, because you don't have to be exactly on the ecliptic to see a transit. Besides, no planets are exactly on the ecliptic. Mercury, for example, is inclined by 7°.

[Globe199]

Pluto crosses the ecliptic two times every Plutonian year , so there is a chance of a transit about every 124 years .

Also, Pluto's high orbital eccentricity causes it to be on one side of the ecliptic for a much greater part of its time than the other planets. (Though I'll be damned if I can find the exact figure.)

[Globe199]

My non-math skills lead me to believe that the period of possible transits (i.e., Pluto crossing the ecliptic) would follow this pattern: 94 years, then 154 years, then 94 again, etc. This is based on my non-skills of elliptical geometry

[frankuitaalst]

My non-math skills lead me to believe that the period of possible transits (i.e., Pluto crossing the ecliptic) would follow this pattern: 94 years, then 154 years, then 94 again, etc. This is based on my non-skills of elliptical geometry

I've made a little animation how Pluto sees the inner solar system over a full Plutonian year here :
http://www.orbitsimulator.com/cgi-bi...1339191119/0#0
For the possible Earth transits I see an inter period of 159 years and 89 years .

[Globe199]

I've made a little animation how Pluto sees the inner solar system over a full Plutonian year here :
http://www.orbitsimulator.com/cgi-bi...1339191119/0#0
For the possible Earth transits I see an inter period of 159 years and 89 years .

You may be right on the period. I realized after I typed it that my math was probably way off. But maybe I wasn't that far off

[Globe199]

That's pretty trippy. I'm not totally sure what I'm looking at, but I like it. I have a thread over at physicsforum.com seeking more information on orbital calculations and what not.

[frankuitaalst]

You may be right on the period. I realized after I typed it that my math was probably way off. But maybe I wasn't that far off

Your estimation was quite well . I didn't want to correct you but wanted to generate some background view how transists form .
What you are looking at in the link provided is a simulation how the orbits of the inner planets , including Earth , look like if one woukd stand on Pluto and aim its binoculars to the sun , taking one picture every 12 hours and refresh the image every Earth year . One can see then how the orbits change in perspective during one plutonian year . If the planets crosses the sun in the center we can see a transit .