Scientists reconstruct the Pioneer spacecraft anomaly  At the
American Physical Society meeting: What is putting a drag on the
twin Pioneer spacecraft? Is it uneven heating? Or does gravity
deviate from what is expected?   Editor's Note: JR Minkel is in
St. Louis this week for the annual "April meeting" of the
American Physical Society. See his other blog posts on dark
matter, the Higgs boson and the timeline for the Large Hadron
Collider, and check back for frequent updates.  ST. LOUIS—Ten
years ago, NASA researchers discovered that the Pioneer 10 and
11 spacecraft had fallen slightly behind course during their
35-year journeys to the outer reaches of the solar system. In
what has become known as the Pioneer anomaly, which was the
subject of one of the talks this weekend at the American
Physical Society here in St. Louis, nobody knows for sure why it
happened. It probably stemmed from leaking gas or heat.  But
there's also the possibility, however remote, that gravity
doesn't behave the way we expect. Until