Meteorites and golf balls
2018-08-30
It turns out that golf balls might just be key to understanding the solar system.
Planetary scientists at NASA’s Johnson Space Center found evidence that Earth and other terrestrial planets may have formed from clusters of space dust the size of golf balls.
Justin Simon, a scientist in the Astromaterials Research and Exploration Science (ARES) Division at Johnson, made the discovery while co-leading a study of two ancient meteorites, Allende and NWA 5717. The meteorites were found in fragments across Mexico and North Africa and are believed to have formed well before the terrestrial planets we see today.
Over the course of six years, Simon and his research team examined thousands of particles within electron microscope images of the meteorites to learn more about their structure and composition. The team had to review and detail each scan individually to ensure total accuracy. To accomplish this monumental task, Simon partnered with the Lunar and Planetary Institute to bring summer interns to Johnson to assist with the analysis.
“This work wouldn’t have been possible without the help of all those enthusiastic students,” Simon said. “This groundbreaking research really highlights the value of a NASA internship.”
Simon and his co-investigator, Jeffrey Cuzzi from NASA’s Ames Research Center, found the meteorites were much more complex than previously thought. The biggest revelation was the discovery of three- to four-centimeter clusters of particles within their structure and its implications for how objects could have grown larger in the early solar system.
“This is the first evidence that planets formed by pieces of dust sticking together to form larger objects,” Simon said. “There have been a lot of theories about planetary formation, but many have been stymied by a factor called the ‘bouncing barrier, which stalls growth.’”
The bouncing barrier theory states that planets cannot directly form through the accumulation of small dust particles colliding in space because the impact would knock off previously attached aggregates. Astrophysicists had hypothesized that if the clumps colliding were larger — the size of a small ball — they could exert enough gravity to hold themselves together in clusters to form larger bodies.
It looks like Simon just might have proved this.
“Our discovery shows the theory may actually work and be real,” Simon said. “It’s big a step forward scientifically.”
Planetary scientists at NASA’s Johnson Space Center found evidence that Earth and other terrestrial planets may have formed from clusters of space dust the size of golf balls.
Justin Simon, a scientist in the Astromaterials Research and Exploration Science (ARES) Division at Johnson, made the discovery while co-leading a study of two ancient meteorites, Allende and NWA 5717. The meteorites were found in fragments across Mexico and North Africa and are believed to have formed well before the terrestrial planets we see today.
Over the course of six years, Simon and his research team examined thousands of particles within electron microscope images of the meteorites to learn more about their structure and composition. The team had to review and detail each scan individually to ensure total accuracy. To accomplish this monumental task, Simon partnered with the Lunar and Planetary Institute to bring summer interns to Johnson to assist with the analysis.
“This work wouldn’t have been possible without the help of all those enthusiastic students,” Simon said. “This groundbreaking research really highlights the value of a NASA internship.”
Simon and his co-investigator, Jeffrey Cuzzi from NASA’s Ames Research Center, found the meteorites were much more complex than previously thought. The biggest revelation was the discovery of three- to four-centimeter clusters of particles within their structure and its implications for how objects could have grown larger in the early solar system.
“This is the first evidence that planets formed by pieces of dust sticking together to form larger objects,” Simon said. “There have been a lot of theories about planetary formation, but many have been stymied by a factor called the ‘bouncing barrier, which stalls growth.’”
The bouncing barrier theory states that planets cannot directly form through the accumulation of small dust particles colliding in space because the impact would knock off previously attached aggregates. Astrophysicists had hypothesized that if the clumps colliding were larger — the size of a small ball — they could exert enough gravity to hold themselves together in clusters to form larger bodies.
It looks like Simon just might have proved this.
“Our discovery shows the theory may actually work and be real,” Simon said. “It’s big a step forward scientifically.”
False-color image of NWA 5717 meteorite showing the apparent golf ball size clumps.
Credit: Justin Simon
Mosaic photograph of the ancient Northwest Africa 5717 ordinary chondrite with clusters of particles.
Credit: Justin Simon