Current Events – Collision of Two Worlds

“For the invisible things of Him from the creation of the world are clearly seen, being understood by the things that are made, even His eternal power and Godhead; so that they are without excuse: Because that, when they knew God, they glorified Him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. Professing themselves to be wise, they became fools, … they did not like to retain God in their knowledge …” Romans 1:20–22, 28. Also, see Genesis 1.

About 4.5 billion years ago, just after the solar system formed, the relatively small planetary body that would become Earth experienced something extreme. A planetary embryo—probably about the size of Mars—called Theia collided with Earth, spinning the moon off into orbit around the nascent planet.

Overall, scientists agree that this moon-forming collision happened, but a current debate raging in planetary science hinges upon just what that collision was like. A new study in the journal Science this week may help solve the mystery of what went down in the early days of the solar system.

Usually, each body in the solar system has different ratios of various elements. According to Edward Young, a co-author of the new study, it’s “almost unheard of” for two bodies to have the same ratio of oxygen isotopes. In fact, these ratios are usually so unique that researchers treat them as “fingerprints” for bodies.

However, a new analysis performed by Young and his team shows that the Earth and moon actually have a very similar—if not identical—ratio of oxygen isotopes.

Young and his team analyzed seven moon rock samples brought back from three Apollo missions to the lunar surface. Earlier analyses had shown that the oxygen isotope ratio is different on the moon compared to the Earth, but this new, detailed study appears to suggest that the ratios are essentially the same.

The new finding could mean that instead of dealing Earth a glancing blow, Theia’s impact packed a bigger punch, forcing the material that composes the two bodies to mix more than previously expected, due to a “high-energy, high-angular-momentum impact,” the study reads.

Young’s work supports computer models of the moon-forming impact that show Theia dealing Earth a devastating blow, effectively causing the two bodies to completely mix their compositions together, creating two cosmic objects with very similar if not the same oxygen isotope ratios.

“Our measurements essentially say that the moon and the Earth are identical within the precision [of the instruments],” Young said.

“Since they’re identical, it says that these newer models that have been coming out in the last couple years say there might be a way to slow the Earth and the moon down after the impact and therefore maybe the impact really was a planet-crushing head on collision.”

“Our work suggests that the people creating those kinds of models are on the right track.”

But it’s not a cut and dry case. The mechanism of that mixing—whether it was a direct impact from Theia or something else entirely—isn’t yet clear.

“I am not sure that Young et al demonstrate a mechanism that leads to thorough mixing, but they certainly document that there is a need for some process to mix all the materials to homogenize oxygen,” Jeff Taylor, a scientist at the Hawaii Institute of Geophysics and Planetology who wasn’t affiliated with the study told Mashable via email.

Scientists will need to tackle the mysteries of the moon’s formation from two different angles.

On the one hand, researchers need to refine comprehensive models that will explain how different forms of impacts could lead to our current moon, while research also needs to proceed to examine the chemistry of the lunar body and compare it to Earth.

By combining those two ways of attacking the issue, Young said, lunar researchers might one day be able to get a comprehensive idea of how Earth’s closest neighbor really formed.

Really? Genesis 1 has a much simpler and believable explanation of how this universe came into being. “In the beginning God created …”