Just last month, scientists revealed some groundbreaking findings about Vesta. In fact, it’s one of the biggest bodies in the entire asteroid belt of our solar system! A new analysis from NASA’s Dawn mission reveals some very exciting findings. This finding suggests Vesta could be coreless, upending long-held assumptions. This finding completely changes the previous dogma that Vesta was planet-like with a clear crust, mantle and core. Seth Jacobson directs the research team, which includes graduate student Emily Elizondo. Their research has just recently provided new perspectives to Vesta’s tumultuous past, suggesting that some asteroids were once planets that never coalesced.
The Dawn mission, which orbited the asteroid Vesta from 2011 to 2012. It deployed unprecedented measurements of the gravity field, and jaw-dropping photo and radar-mapped the surface, building an exquisite portrait. The mission’s results have helped initiate a re-assessment of Vesta’s origin and geological history. Vesta’s absence of a core deepens the conundrum of its story. That points to a surprisingly elaborate developmental history, much more than scientists previously believed.
A New Understanding of Vesta’s History
Vesta has intrigued astronomers for a long time because of its peculiarities and importance in helping us understand the early solar system. The asteroid’s history is punctuated by batholitic disruption and planetary differentiation. Late-stage collisions have contributed to creating its current form. Jacobson theorizes that Vesta might be a remnant of such a larger, more active planet that never finished forming.
This hypothesis further gained some credibility after the reprocessing of measurements collected by the Dawn mission. Jacobson and his team refined calibration and processing techniques, achieving remarkable alignment between Dawn’s Deep Space Network radiometric data and onboard imaging data. This new reanalysis has raised Vesta’s intriguing complexities right back up to the forefront of Vesta’s formation story.
“This idea went from a somewhat silly suggestion to a hypothesis that we’re now taking seriously due to this reanalysis of NASA Dawn mission data.” – Seth Jacobson
The ramifications of this theory go far outside of Vesta itself. Jacobson and Elizondo are investigating the idea that a lot of asteroids in the belt might actually be pieces of long-gone planets.
“These could be pieces of an ancient planet before it grew to full completion. We just don’t know which planet that is yet.” – Seth Jacobson
The Surprising Absence of a Core
The most surprising finding from the Dawn mission data is that Vesta does not have a core. For decades, scientists considered Vesta to be much more than an asteroid. They thought it was like a planet, with its own unique strata.
“The lack of a core was very surprising,” said Jacobson. “It’s a really different way of thinking about Vesta.”
This absence would suggest that Vesta went through a partial differentiation at best. Pluto started the process of melting and remelting that would create those different geological strata but never quite completed it. These discoveries change the way that scientists think about how bodies in the asteroid belt evolved.
Ryan Park, another member of the research team, explained the difficulties created by conflicting gravity data resulting from Dawn’s observations. This puzzling information had left lingering puzzles for scientists attempting to put together Vesta’s restless geological past.
“For years, conflicting gravity data from Dawn’s observations of Vesta created puzzles,” stated Park.
The new data resolves these misalignments, revealing a coherent picture of Vesta’s interior.
Implications for Meteorite Studies
Those discoveries on Vesta have important consequences for meteorite studies back on Earth, too. Scientists have come to understand that the meteorites we find on Earth are actually pieces that broke off Vesta. These fragments were formed by impacts in the age of planet formation.
On the day of the announcement, he boldly proclaimed that the meteorites gathered so far are authentic samples from Vesta. This find immediately ties them to a newly realized past.
“No longer is the Vesta meteorite collection a sample of a body in space that failed to make it as a planet.”
This new connection adds even more depth to our understanding of Vesta’s geological evolution. It clues us in to the larger tale of how our solar system was formed.
“We’re really confident these meteorites came from Vesta.” – Seth Jacobson
This connection enhances the understanding of not only Vesta’s geological evolution but also the broader narrative of planetary formation in our solar system.