BOSTON — Big news in the search for dark matter may be coming in about two weeks, the leader of a space-based particle physics experiment said today (Feb. 17) here at the annual meeting of the American Association for the Advancement of Science.

That's when the first paper of results from the Alpha Magnetic Spectrometer, a particle collector mounted on the outside of the International Space Station, will be submitted to a scientific journal, said MIT physicist Samuel Ting, AMS principal investigator.

Though Ting was coy about just what, exactly, the experiment has found, he said the results bear on the mystery of dark matter, the invisible stuff thought to outnumber regular matter in the universe by a factor of about six to one.

Monday morning, at the Moriond conference, the most expected talk in the dark matter session contained unfortunately no results. Although the AMS collaboration was supposed to reveal their very first measurements, Bruna Bertucci could only present apologies to an eager audience since the approval process had not been completed in time for the conference,

The AMS or Alpha Magnetic Spectrometer is a particle detector that was installed on the International Space Station in May 2011 and has been collecting data ever since. The scientific community is now eagerly waiting to hear about their results, in the hope of getting some clues as to what makes up 24% of all content of the Universe, namely what are the mysterious particles that form dark matter.

AMS is due to release data that will compare the flux of positrons in outer space with the flux of electrons. Positrons are the antimatter counterpart of electrons. The interest all stems from the fact that a few years ago, the PAMELA collaboration observed a larger positron flux at high energy than expected. It is relatively easy to think of various sources of electrons since we live in a world made of matter. But what could be a source for antimatter? One possible explanation is to suppose that dark matter particles are annihilating into pairs of electrons and positrons, and hence providing a source of positrons.

Another group operating a satellite-born experiment, the FERMI-LAT collaboration partially confirmed that observation but only AMS has all the capabilities to really cross-check the PAMELA results. We will have to be a bit more patient until the AMS collaboration publishes with its first results.