Mysterious Force Holds Back NASA Probe In Deep Space

The Telegraph (UK) ^ | 2-10-2002 | Robert Matthews

[blam]

Mysterious force holds back Nasa probe in deep space

By Robert Matthews, Science Correspondent
(Filed: 10/02/2002)

A SPACE probe launched 30 years ago has come under the influence of a force that has baffled scientists and could rewrite the laws of physics.

Researchers say Pioneer 10, which took the first close-up pictures of Jupiter before leaving our solar system in 1983, is being pulled back to the sun by an unknown force. The effect shows no sign of getting weaker as the spacecraft travels deeper into space, and scientists are considering the possibility that the probe has revealed a new force of nature.

Dr Philip Laing, a member of the research team tracking the craft, said: "We have examined every mechanism and theory we can think of and so far nothing works.

"If the effect is real, it will have a big impact on cosmology and spacecraft navigation," said Dr Laing, of the Aerospace Corporation of California.

Pioneer 10 was launched by Nasa on March 2 1972, and with Pioneer 11, its twin, revolutionised astronomy with detailed images of Jupiter and Saturn. In June 1983, Pioneer 10 passed Pluto, the most distant planet in our solar system.

Both probes are now travelling at 27,000mph towards stars that they will encounter several million years from now. Scientists are continuing to monitor signals from Pioneer 10, which is more than seven billion miles from Earth.

Research to be published shortly in The Physical Review, a leading physics journal, will show that the speed of the two probes is being changed by about 6 mph per century - a barely-perceptible effect about 10 billion times weaker than gravity.

Scientists initially suspected that gas escaping from tiny rocket motors aboard the probes, or heat leaking from their nuclear power plants might be responsible. Both have now been ruled out. The team says no current theories explain why the force stays constant: all the most plausible forces, from gravity to the effect of solar radiation, decrease rapidly with distance.

The bizarre behaviour has also eliminated the possibility that the two probes are being affected by the gravitational pull of unknown planets beyond the solar system.

Assertions by some scientists that the force is due to a quirk in the Pioneer probes have also been discounted by the discovery that the effect seems to be affecting Galileo and Ulysses, two other space probes still in the solar system. Data from these two probes suggests the force is of the same strength as that found for the Pioneers.

Dr Duncan Steel, a space scientist at Salford University, says even such a weak force could have huge effects on a cosmic scale. "It might alter the number of comets that come towards us over millions of years, which would have consequences for life on Earth. It also raises the question of whether we know enough about the law of gravity."

Until 1988, Pioneer 10 was the most remote object made by man - a distinction now held by Voyager 1. Should Pioneer 10 make contact with alien life, it carries a gold-plated aluminium plaque on which the figures of a man and woman are shown to scale, along with a map showing its origin that Nasa calls "the cosmic equivalent of a message in a bottle".

[going hot]

so the alien intelligence thought that the probe was named "V'ger"

I always wondered how a machine based society/intelligence that lived so far from earth could read enough english and annunciate the letters correctly to come up with "Vger" with the letters painted on the side of the spacecraft. I mean, how did they know that the scribbling was even a language, and not some form of competition stripes??

It was amazing that the visible letters were pronounced correctly in the first place. :-)

[AmerRepb]

Pioneer 10 is moving in the opposite direction to the Sun's motion through the galaxy, the solar apex direction. The motion of the heliospheric boundary through the local interstellar medium may cause a bow wave upstream of the heliopause and a tail downstream. The flow of subatomic particles making up the solar wind is expected to undergo a shock transition from supersonic to subsonic before reaching the heliopause. This shock is called the solar-wind termination shock. Here termination refers to the end of supersonic flow and not the end of the solar wind, which occurs at the heliopause. Prior to Pioneers 10 and 11, the effect of the solar wind was thought to extend to the vicinity of Jupiter or perhaps a bit farther. The Pioneer scientists now predict the distance from the Sun at which the terminal shock may be encountered is from 60 to 100 astronomical units (AU) or more, where an AU is defined as the distance of the Earth from the sun ~ 150 million kilometers (~93,000 million miles). For reference, the distance to the outermost planet is ~ 40 AU's.

My best guess is that the winds have changed from NW and are now Southerly winds at 15 (bunch of zeros) to 20 (many more zeros) mph creating the drag.

[blam]

Very interesting thanks.

[JohnBovenmyer]

Hmmm at 6 mph per century Pioneer should come to a dead stop in about 4500 centuries ( if that figure of 27000 mph is correct) and thus it will never reach another star.

So mankind is being quarantined.

[RadioAstronomer]

This has been discussed for a few years now. See:

http://prola.aps.org/abstract/PRL/v81/i14/p2858_1

http://www.aip.org/enews/physnews/1998/split/pnu391-1.htm

http://www.geocities.com/solarstormmonitor/Pioneer.html

[RadioAstronomer]

Except if you follow my links, you will notice that spacecraft traveling in opposite directions on opposite sides of the solar system are experiencing the same anomaly.

[Timesink]

Until 1988, Pioneer 10 was the most remote object made by man - a distinction now held by Voyager 1.

How did Voyager get farther out? Was it launched at a higher rate of speed, or did Pioneer 10 spend more time orbiting planets, or what?

[jlogajan]

Or perhaps radio waves don't travel at the speed of light forever. Maybe they slow down by 6 mph every 100 years.

That's known as the tired light theory. However, spectral emission and absorption lines from distant stars and nearby starts arrive on the same wavelenghts. If light slowed down with time, the arriving wavelengths would all be longer, and therefore all the spectral lines shifted for the more distant stars. There is no hint of that. Therefore light doesn't get tired or slow down with age.

[Flyer]

We are far from being "done" with physics.

Yep. We don't even know enough to be dangerous yet.

[samtheman]

I have also heard that our little neck of the interstellar woods is remarkable free of such stuff. Gives us great views into space and apparently we can thank two fairly recent and close super nova for the excellant visibility. Shock waves from the explosions apparently blew all the normal interstellar gas and dust out of our neighborhood.

The views might be great but the bad news is that the relative lack of interstellar gas in our region might be a future obstacle to bringing our Ramscoop Technology online.

[samtheman]

Excellent.

[Revelation 911]

Maybe these is something to that giant sucking sound Ross Perot was babbling on about...

Nope - that only lasts 8 years & coincides with the election cycle

[DB]

I like;

Very funny, Scotty. Now beam down my cloths...

[leadpenny]

Any connection between the subject of this thread and the APOD for 10 Feb 02?

[PatrickHenry]

mystery force Space probe bump

Thanks for the ping. I am strangely attracted to this thread.

[Rebelbase]

Sorry, I grew up with phonix.

[Physicist]

Last May on FreeRepublic I put forth this hypothesis about the deceleration of the probes. I threw it around the physics department here, and everyone I talked to thought it was a likely answer. I wanted (and still want!) to write a paper with the full explanation, but first I need to get accurate position data for the probes, which I've so far been unable to obtain.

[Yeti]

Hmm, they didn't mention drag due to interstellar gas, did they? That would seem to be a candidate, would it not?

My thoughts exactly.

Funny that these guys would assume that our understanding of the laws of physics is way off before they consider the possibilty that we may have slightly mismeasured or miscalculated the density of matter in the region. Or the gravitational pull of the solar system en masse as the vehicles become more distant. Or the flux of matter moving into the solar system.

One ten-billionth the force of gravity is more likely rounding error in computations than anything else. Or how about accumulation of mass on the probes due to collisions with microparticles?

[Buffalo Head]

This is the sort of childish input to which I was noting. The chat rooms for such folks must be full so they post their drivel here.

Al Gore invented Pioneer...

Maybe these is something to that giant sucking sound Ross Perot was babbling on about...

"Very funny, Scotty. Now turn the tractor beam OFF."

It's either the 6% tax congress put on them for renouncing their citizenship or Hillary Care's impuded rent tax pulling them towards the National Treasury.

Maybe it's that Brown Dwarf Art Bells been talking about re Hillary.

An a** that massive

This is obviously due to cosmic warming.

I believe this effect can be blamed on Enron!

no, i believe that would have been gary coleman.

JESUS is coming and he aint happy.

Global warming?

Etceteras.

[4CJ]

Could it be that light particles (photons) are hitting the probes and slowing them down?

Well, duh (as the old joke goes), if that's the case - go at night.