A cloud of material from elsewhere in the galaxy has slipped inside our solar system's protective bubble, and it is fundamentally different from anything else scientists have ever seen. The "alien matter" was spotted and analyzed by a NASA probe exploring the edge of the solar system, CBS reports. The material, the remnants of exploded stars that drift in clouds through interstellar space, has 74 oxygen atoms per 20 neon atoms, compared to the 111 oxygen atoms per 20 neon atoms found in our solar system.
"These are important elements to know quantitatively because they are the building blocks of stars, planets, people," the lead researcher says. "We discovered this puzzle: Matter outside our solar system doesn't look like material inside our solar system." The low proportion of oxygen suggests that plenty of oxygen atoms could be "locked up" inside galactic material like grains of ice and dust, the researchers say. (Read more solar system stories.)