Press Release

Solve the Mystery — The Pioneer Anomaly

By SpaceRef Editor
May 12, 2005
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Dear Society Member,

Something strange is happening in the outer reaches of our solar system. The Pioneer 10 and 11 spacecraft are not where they are supposed to be.

These missions, launched in 1972 and 1973, have covered hundreds of millions of miles, heading toward the edge of our solar system. But something is holding them back. Each year, they fall behind in their projected travel by about 8,000 miles.

Scientists are being forced to consider the unthinkable: something may be wrong with our understanding of The Laws of Physics. Jet Propulsion Laboratory scientist Dr. John Anderson and his colleagues have been searching for an explanation since 1980. But as of yet, they have found nothing conclusive.

Right now, the Planetary Society has a once-in-a-lifetime opportunity to help solve this mystery of epic proportions…and maybe even rewrite the world’s science textbooks!

After years of analysis, but without a final conclusion, NASA, astonishingly, gave up trying to solve this “Pioneer Anomaly” and provided no funds to analyze the data. The Pioneer data exists on a few hundred ancient 7- and 9-track magnetic tapes, which can only be read on “antique” outdated computers. The agency is going to scrap, literally demolish, the only computers able to access and process that data in the next few months!

So unless we act now, an extraordinary, once-in-a-lifetime opportunity will be lost.

Help save the “Pioneer Anomaly” data and solve this mystery at:

Let me explain this mystery in more detail. It starts with something that, when first noticed, seemed trivial: two of America’s oldest space probes — the Pioneer probes which studied Jupiter and Saturn — seemed to be not quite where they should have been.

The trajectories of these two spacecraft were deviating from the known laws of motion, the laws given to us by Newton and Einstein, and “losing” about 8,000 miles in a year. And…that figure keeps growing!

That may not sound like much when you are dealing with spacecraft traveling at nearly 30,000 miles per hour relative to the Sun. But it was enough to alert Dr. John Anderson, the Jet Propulsion Laboratory scientist who was charged with monitoring the two spacecraft.

Being a careful and patient space scientist, he refused to jump to conclusions. He expected a simple explanation would surface. Maybe the solar wind was affecting the craft. Maybe heat leakage from the nuclear batteries was the cause. So he spent years quietly searching for an answer. Eventually he found other high-level researchers, including Eunice Lau, Slava G. Turyshev and Michael Nieto, to help seek an explanation.

For the last 10 years, the team has tried to explain the anomaly with conventional physics, but ultimately ruled out every possibility they considered. The most obvious explanation still lies in the spacecraft themselves, but the limited data analyzed does not support any suggested mechanism.

What could possibly be the cause of this anomaly? No one knows yet. But the team who has labored on this has begun to suggest other possibilities — any one of which would be truly astounding if proved true.

Could it be

. . . Dark Matter?

. . . An Acceleration of Time?

. . . A Change in the Laws of Gravity?

So, you can see, this is a mystery of the first order. There appear to be two ways to possibly settle this baffling question once and for all.

–The first option would be to launch a dedicated space probe to investigate, following the Pioneer 10 trajectory, and trying to recreate the anomaly. This particular mission is an intriguing possibility, but it would cost at least $500 million and is not now in the cards.

— The second option is a lot simpler: open up all of the data ever returned by the two Pioneer spacecraft including the 15 years of data from before 1987 — and examine it in excruciating detail. Doing this will provide a more precise picture of what happened to Pioneer 10 over a much longer period of time, possibly giving us the critical answer we need.

The second option is the best course of action. This exciting project will cost about $250,000 to save the data from destruction and do the complex analyses required to seek an answer to this mystery…a small price to pay in order to potentially revise our understanding of gravity! Astonishingly, NASA is not ready to do this.

If we do not act now, all of the crucial, older data could be ignored or lost forever.

To act now go to:

That’s where The Planetary Society — and you as a Member — enter the picture.

You and I — all of us who are Members of the Society — have to start working immediately to see where this knowledge can take us.

Once the data is recovered, we can work with Dr. Anderson and his colleagues to do an exhaustive analysis of this potential goldmine.

But we must have our Members’ support and participation to move forward with any project of this magnitude. Ultimately it is your vision, your enthusiasm, and your generosity that will move this pioneering project ahead. I urge you to let us know your decision as soon as possible — today if you can.

We don’t have a moment to lose. NASA could begin demolishing their old computer equipment in a few short weeks. The data and this one-time opportunity for discovery will be lost forever. The clock is ticking. We’ve got to move quickly!

I hope we can count on you.


Louis D. Friedman Executive Director

P.S. If you haven’t received it already, you will probably be getting a letter about this project in the mail. If you have already sent in your donation we thank you.

For more information on the Pioneer Anomaly go to:

SpaceRef staff editor.