Artist rendering of the Genesis spacecraft during collection phase of mission.
Credit: NASA/JPL-Caltech
PASADENA: Our Sun and its inner planets may have formed differently than previously thought, according to researchers who have analysed samples from NASA's 2004 Genesis mission.
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 the University of California, Los Angeles (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."
Different compositions
The air on Earth contains three different kinds of oxygen atoms which are differentiated by the number of neutrons they contain. Nearly 100% 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.
Another paper detailed differences between the Sun and planets in the element nitrogen. Like oxygen, nitrogen has one isotope, N-14, that makes up nearly 100% of the atoms in the Solar System, but there is also a tiny amount of N-15.
Researchers studying the same samples saw that when compared to Earth's atmosphere, nitrogen in the Sun and Jupiter has slightly more N-14, but 40% less N-15. Both the Sun and Jupiter appear to have the same nitrogen composition. As is the case for oxygen, Earth and the rest of the inner Solar System are very different in nitrogen.
Generating plenty of questions
"These findings show that all Solar System objects including the terrestrial planets, meteorites and comets are anomalous compared to the initial composition of the nebula from which the Solar System formed," said Bernard Marty, a Genesis co-investigator from Centre de Recherches Pétrographiques et Géochimiques in France and the lead author of the other new Science paper.
"Understanding the cause of such a heterogeneity will impact our view on the formation of the Solar System."
Data were obtained from analysis of samples Genesis collected from the solar wind, or material ejected from the outer portion of the Sun. This material can be thought of as a fossil of our nebula because the preponderance of scientific evidence suggests that the outer layer of our Sun has not changed measurably for billions of years.
Capture Theory confirmed?
Michael Woolfson's Capture Theory explains this - at least it might - with the scenario that the proto-Sun captured material from a lower mass, diffuse proto-star, and then captured material, collapsing as large proto-planets, was braked into orbit around the Sun in a circum-stellar disk. Tidal forces cause the regular Moons to be spun off the gas giants, while Earth and Venus were once much larger and produced a series of large rocky Moons (Mercury, Luna and Mars.) The encounters with the Sun's disk caused the planets to precess and undergo close encounters, one of which was a collision between Earth and Venus. This blew off their outer layers, but left the cores in new orbits, with the rest of the debris becoming the asteroids & comets etc. Proto-Venus was enriched in deuterium - as it still is - and this produced a thermonuclear detonation that created many of the other isotopic anomalies seen in meteorities today.
Capture Theory confirmed ?
Well -
does not the Rings of Saturnus prove how the Planetary system began and
as also the craters of the Moon further developed the Planets build - up ?.
Arne Strand.Sweden.