Pluto Probe Snaps Jupiter Pictures

sighted writes "The New Horizons probe, on its way to Pluto and beyond, is now speeding toward Jupiter. Today the team released some of the early data and pictures, which are the first close-range shots of the giant planet since the robotic Cassini spacecraft passed that way in 2001."

Re:How long does this take?

[rumith]

10 hours from Pluto in average. 45 minutes from Jupiter in average. Don't know whether they'll in their aphelion or perihelion now, so can't say more precisely.

Re:How long does this take?

[Bucko]

The New Horizons Site [jhuapl.edu] keeps track of the spacecraft position and distance. According to the last mission update, the light travel time is now over 1h 30m.

Re:Communication a problem

[AndyST]

> it takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009 Voyager I has a speed of about 17 km/s. At that speed it takes 114440 years to fly the 4,4ly to Alpha Centauri.

well this is where they are

[rucs_hack]

their exact position today can be found in the JPL Horizons database
http://ssd.jpl.nasa.gov/horizons.cgi [nasa.gov]

so using Sol as Origin [0,0,0], with distance in km and km/s velocity measures:
XYZ position and velocity in Km and Km/sec
V prefix = velocity,

Jupiter
A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-3.523007925524937E+08 Y =-7.203651223053448E+08 Z = 1.087397270750013E+07
  VX= 1.158611696091788E+01 VY=-5.127849980674650E+00 VZ=-2.378734986696975E-01

Earth
  A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-7.005151113800500E+07 Y = 1.294518808525130E+08 Z =-1.647040773451328E+03
  VX=-2.669513206382950E+01 VY=-1.429493892074527E+01 VZ=-5.052885705412180E-04

And the Horizons probe itself is here:
A.D. 2007-Jan-19 00:00:00.0000 (CT)
  X =-3.141011231236297E+08 Y =-6.673772181265557E+08 Z = 9.200702373118341E+06
  VX= 1.154291925552546E-01 VY=-1.978644188955009E+01 VZ= 1.493924692614632E-01

However it's too early to work out the times taken for signals to travel based on these positions. I need more coffee.

Misinformative

[Cheesey]

As I understand it, the speed of light applies not only to physical objects, but also information itself. No-one knows any way to move information faster than light. If you've found a way, that's truly revolutionary, but in the meantime your post sounds a bit like a "free energy" claim. Can you back it up with some citations?

Re:Communication a problem

[Ihlosi]

4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009.

Whoa, I didn't know that these things made 0.1c ...

Wait ... they don't. I think you meant "in later 12009".

+2 Interesting!? Mod Parent Down

[physicsnick]

it takes 8 minutes to send a signal as far as mars and 4 years to send one to Alpha Centuri, which Voyager 1 is predicted to reach in later 2009.

Voyager 1 will take on the order of several hundred thousand years to reach Alpha Centauri.

The traditional explanation for this is that the graviton can only travel at the speed of light and as such will take 10 minutes to travel from one particle to the other, so far so good.

The 'traditional' explanation? Gravitons are hypothetical at best, and currently mathematically useless. Quantized force mediators do not need to "intercept" a moving particle at a distance; they are virtual, and there are infinitely many of them in all directions.

By changing the mass of the ball (simple enough to do with a powerful laser)

This is all nonsense. Even if this were true, your probe is also receiving gravitons from every other atom in the universe. The effect of varying a "ball of mass" would not even be measurable. Just because a sizable block of text with "sciency words" is posted doesn't mean it's meaningful, and certainly doesn't deserve mod points. Please mod parent down, and please read things before giving points!

Re:All these planets are yours

[zwarte piet]

That only applies after 2010.

Re:How long does this take?

[Tom Womack]

http://pluto.jhuapl.edu/science/data_collection.ht ml [jhuapl.edu] says that the transmission is at 38kbit/second from Jupiter, and will be at around 450bit/second from Pluto.

Cassini runs at 82kbit/second from Saturn, but it's a probe with a larger power budget.

The imager takes one-megapixel, 16bpp images, and compresses them to 100kbyte files for initial transmission, saving the originals in a few gigabytes of onboard flash; it can be instructed to send back uncompressed images if there's something interesting visible.

So an image takes about 20 seconds to transmit, plus about six minutes if you want the uncompressed version; and it takes 45 minutes to get to Earth from Jupiter. From Pluto, the images will take half an hour for the preview and twelve hours for the uncompressed image.

Re:well this is where they are

[KiloByte]

Pythagoras' theorem says the distance in R3 (ie, euclidean space) is sqrt((x1-x2)^2+(y1-y2)^2+(z1-z2)^2).
That is, the distance between Earth and Jupiter right now is: 8.95528824E8 km.

Dividing that by c gives 2987 seconds. So, right now the half-ping is 50 minutes.

By similar calculation, you can get that EarthNew Horizons is 2779.975 s =~ 46 minutes.

Re:Communication a problem

[physicsnick]

If I recall my particle physics correctly, the way ATLAS at the LHC will be detecting gravitons is via their leptopic decay products, and regard that as the optimal way.

You're thinking of the Higgs boson. We are nowhere near approaching the level of technology required to detect gravitons, and the mathematics they give rise to doesn't even work. The only real reason we have to believe they exist is because the other forces also have quantized mediators.

Re:How long does this take?

[duh P3rf3ss3r]

According to the last mission update, the light travel time is now over 1h 30m.

I have no idea where you got that. From the page you sent us to, the distance to the spacecraft is currently 5.57AU. Dividing that by c gives 2779.46 s or 46.32 minutes. Perhaps it's written somewhere on that site that the round trip light time is just over an hour nd a half. But that's not at all the same thing.

Re:well this is where they are

[FallOfDay]

The rough & ready, easy-on-the-eye (!), pictorial version is as follows:
http://pluto.jhuapl.edu/mission/whereis_nh.php [jhuapl.edu]

Re:well this is where they are

[AvyTech]

I just got grrly wood. Yay for me.

Re:Communication a problem

[Teancum]

I think he has mistaken the idea that Voyager will leave the solar system in 2009, as defined by the region of space where the solar wind is overcome with other stellar matter from the rest of the Milky Way, and presumably in the region of space roughly where the Oort Cloud is likly to be located at. At that point you could presumably suggest that it is in interstellar space and the gravitational influence of the Sun is insignificant compared to other objects in the rest of the Galaxy.

While that is in reality a major accomplishment in terms of having a human artifact leave the solar system, it is a far cry from being able to reach another star system, especially Alpha Centauri. Especially as Alpha Centauri is hardly in the plane of the ecliptic (where most of the planets are located at), requiring some very precise trajectory calculations that would have made the visit to the outer planets by Voyager too difficult to perform.

The primary mission of Voyager was to visit the gas giants of the Solar System, and it did that spectacularly. Anything else it has done or is doing now is incidental extra science, as we are now getting scientific measurements of the environment that is very far from the Earth.

Re:+2 Interesting!? Mod Parent Down

[Cyberax]

It has been measured, see http://www.arxiv.org/abs/gr-qc/0501001 [arxiv.org] . The result of this measurement - speed of gravity is between 0.8c and 1.2c, which is consistent with gravity propagating at 1c.