Asteroid Vesta is currently the second largest asteroid in the solar system, having been studied in-depth by NASA’s Dawn spacecraft between July 2011 and September 2012. But a recent study published in Nature Astronomy sheds new light on this intriguing world’s formation and evolution, which could challenge how planetary bodies in the early solar system grew from primordial dust and gas billions of years ago.
Previous data obtained from the Dawn spacecraft was used to analyze Vesta’s rotational characteristics, which inferred its interior composition as being partially differentiated. This means that it has some layering like the Earth and other planetary bodies, but not enough layering to call itself a planet, so astronomers spent years referring to Vesta as a protoplanet.
For this recent study, astronomers have re-evaluated this data to gain greater understanding of Vesta’s interior with the goal of ascertaining how it formed and evolved over time. In the end, the researchers found that Vesta exhibited uniform layering, as opposed to possessing different layers, meaning Vesta isn’t a protoplanet, but not an asteroid, either. The team proposes two hypotheses for Vesta’s unique interior characteristics: Its interior began the process of becoming layered but was halted early on, or Vesta is a large chuck of a previous planet that was broken off from a large impact long ago.
"For years, conflicting gravity data from Dawn’s observations of Vesta created puzzles,” said Dr. Ryan Park, who is a senior research scientist at NASA JPL and lead author of the study. “After nearly a decade of refining our calibration and processing techniques, we achieved remarkable alignment between Dawn’s Deep Space Network radiometric data and onboard imaging data. We were thrilled to confirm the data’s strength in revealing Vesta’s deep interior. Our findings show Vesta’s history is far more complex than previously believed, shaped by unique processes like interrupted planetary differentiation and late-stage collisions.”
Going forward, the researchers aspire to improve upon these models with the goal of better understanding the formation and evolution of planetary bodies throughout the solar system, including using more Dawn data as was demonstrated in this study.
What new discoveries about asteroid Vesta will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Astronomy, EurekAlert!
Featured Image Credit: NASA / JPL / MPS / DLR / IDA / Björn Jónsson
