( CNN ) -- Nearly two years after it was sent up to the International Space Station , a giant particle physics detector has provided its first results in the search for the mysterious `` dark matter '' believed to be a major component of the universe . The international team running the Alpha Magnetic Spectrometer released its initial findings Wednesday at the European Organization for Nuclear Research , known as CERN , in Switzerland . The scientists are studying flux in cosmic rays , the charged high-energy particles that permeate space , for evidence of the invisible dark matter particles colliding with each other , leading to what is termed `` annihilation . '' A result of this would be a higher presence of the charged particles known as positrons , the antimatter counterpart of electrons . According to a CERN statement , the results announced Wednesday `` are consistent with the positrons originating from the annihilation of dark matter particles in space , but not yet sufficiently conclusive to rule out other explanations . '' How particle smasher and telescopes relate . Over the last few decades , scientists have come to the conclusion that the universe 's composition is only about 5 % atoms -- in other words , the stuff that we see and know around us . That means the rest is stuff we ca n't see . About 71 % is something called `` dark energy , '' and another 24 % is `` dark matter . '' Research is ongoing to figure out precisely what these `` dark '' components are , because they do not interact with ordinary matter and have never been directly detected . The Alpha Magnetic Spectrometer project is being jointly run by scientists from 16 countries , under the leadership of Prof. Samuel Ting of the Massachusetts Institute of Technology . The cosmic ray particle physics detector was carried to the International Space Station on the final flight of the space shuttle Endeavour and installed under NASA direction . Since May 2011 , the detector -- which is mounted outside the space station -- has been sifting through matter , antimatter and other particles as it circles the Earth , with the data sent to hundreds of scientists on the ground for analysis . Their initial conclusions are based on some 25 billion recorded events over the course of 18 months . `` As the most precise measurement of the cosmic ray positron flux to date , these results show clearly the power and capabilities of the AMS detector , '' Ting said , according to the CERN statement . `` Over the coming months , AMS will be able to tell us conclusively whether these positrons are a signal for dark matter , or whether they have some other origin . '' Opinion : How the Higgs can lead us to the dark universe . Physicist Robert Flack , a senior research associate at University College London , told CNN the results from the Alpha Magnetic Spectrometer are significant because they 've `` thrown up a question which may have an answer in dark matter . '' Dark matter remains a mystery because there has been no direct observation of it , he explained . `` We are fairly happy that it exists , we are fairly happy about the kind of shape -- that it envelops galaxies and is much wider than the galaxies themselves , '' he said . `` But what we do n't know yet is what it 's made of -- and that is hampered by the fact that we can not see it and can not detect it , '' he said , because the detectors are made to measure matter as we know it . `` In this case , it will always be an open question until we can pin down what dark matter is made of , '' he said . The scientists involved in the project say the results coming from the spectrometer -- which are much more accurate than in past experiments -- are consistent with a fairly basic dark matter model , Flack said . At the same time , they are right to be hesitant about rushing to make claims that might later prove to be unsubstantiated , he added . The state-of-the art detector , which weighs 8,500 kilograms , is expected to stay in operation through the lifetime of the space station , until 2020 or longer . The results `` could help foster a new understanding of the fields of fundamental physics and astrophysics , '' NASA administrator Charles Bolden said in a statement Wednesday . `` I am confident that this is only the first of many scientific discoveries enabled by the station that will change our understanding of the universe , '' he said . CERN director general Rolf Heuer said the findings so far were `` a great example of the complementarity of experiments on Earth and in space . '' Searches for dark matter are also being carried out at CERN using the Large Hadron Collider , the world 's largest and most powerful particle accelerator , and other laboratories . `` Working in tandem , I think we can be confident of a resolution to the dark matter enigma sometime in the next few years , '' Heuer said . Better 'baby picture ' of the universe emerges . CNN 's Elizabeth Landau contributed to this report .
Scientists have been analyzing data from the Alpha Magnetic Observatory . They are finding evidence of ` ` dark matter '' particles thought to be part of the universe . Alpha Magnetic Spectrometer is mounted outside the International Space Station . It gives the ` ` most precise measurement of the cosmic ray positron flux to date ''