Our sun and its inner planets may have formed differently than previously thought.
ScienceDaily (June 24, 2011) — Researchers analyzing samples returned by NASA's 2004 Genesis mission have discovered that our sun and its inner planets may have formed differently than previously thought.
Data revealed differences between the sun and planets in oxygen and nitrogen, which are two of the most abundant elements in our solar system. Although the difference is slight, the implications could help determine how our solar system evolved.
"We found that Earth, the moon, as well as Martian and other meteorites which are samples of asteroids, have a lower concentration of the O-16 than does the sun," said Kevin McKeegan, a Genesis co-investigator from UCLA, and the lead author of one of two Science papers published this week. "The implication is that we did not form out of the same solar nebula materials that created the sun -- just how and why remains to be discovered."
The air on Earth contains three different kinds of oxygen atoms which are differentiated by the number of neutrons they contain. Nearly 100 percent of oxygen atoms in the solar system are composed of O-16, but there are also tiny amounts of more exotic oxygen isotopes called O-17 and O-18. Researchers studying the oxygen of Genesis samples found that the percentage of O-16 in the sun is slightly higher than on Earth or on other terrestrial planets. The other isotopes' percentages were slightly lower.