Atoms Alien to Our Solar System Detected
Early this year, NASA’s Interstellar Boundary Explorer, the centerpiece of a $169 million mission mapping the frontier of the sun’s influence, detected atoms from interstellar space streaming by Earth that are different from the chemical make-up of the solar system.
“Our solar system is different than the space right outside it, suggesting two possibilities,” said David McComas, IBEX principal investigator, at the Southwest Research Institute in San Antonio. “Either the solar system evolved in a separate, more oxygen-rich part of the galaxy than where we currently reside, or a great deal of critical, life-giving oxygen lies trapped in interstellar dust grains or ices, unable to move freely throughout space.”
The IBEX satellite observed hydrogen, oxygen, neon and helium atoms that originated in interstellar space, the vacuous medium between stars in the Milky Way galaxy and found 74 oxygen atoms for every 20 neon atoms in the interstellar material, compared with 111 oxygen atoms for every 20 neon atoms inside the solar system. Most of the interstellar medium is made up of hydrogen and helium. Heavier elements, such as oxygen and neon, are spread by exploding supernovae at the end of a star’s life cycle, according to NASA.