<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Human-generated antimatter comes from particle accelerators. However, nature also generates antimatter, and uses more than one method to do it. Of course, particle collisions happen in nature as they do in particle accelerators, and those produce antimatter, but some forms of radioactive decay also release antimatter. One particular isotope (I think it is an isotope of aluminum, but I would have to check to be certain) releases a positron. As it happens, this accounts for a considerable amount of antimatter seen near the galactic core. Lots of dust containing this isotope is spread across thousands of light years of space. As it decays, it emits positrons. We can see the annihilation of these positrons, as it emits high energy photons (511 electron-Volts). Earth's magnetosphere, like the magnetosphere of other celestrial objects, collects naturally-produced antimatter. There have been proposals made to harvest this antimatter. <br />Posted by richalex</DIV></p><p>I think it's 511 kilo electron volts. (kev<br /></p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>