Bennu asteroid samples get close-up look at Brown for clues into life’s origin

Analyzing Bennu

As part of their work with the samples, Milliken's team is using reflectance spectroscopy, a technique that analyzes the light reflected at visible wavelengths of light, as well as near- and mid-infrared wavelengths that are longer than what the human eye can see. The key objectives are to better understand what appear to be two distinct types of rock on Bennu and to better grasp the material's complex chemical history.

Researchers at Brown from the lab of Yongsong Huang, a professor of Earth, environmental and planetary sciences, will also be analyzing samples from Bennu when an upcoming shipment of fragments arrives from NASA. Huang's team of organic geochemists plans to shine a spotlight on the organic chemicals present in Bennu samples using a series of newly developed methods. They plan to analyze a slew of volatile or highly volatile organic compounds such as methane, ammonia, formic acid, acetic acid, and small aldehydes and ketones.

"These compounds are the fundamental ingredients for synthesizing more sophisticated biomolecules such as amino acids and nuclear bases, which are also present in Bennu," Huang said. "The analyses can provide key information for cosmic organic synthesis and fill in some of the missing puzzle pieces on how organic life may have started on Earth."

So far, the first published studies of Bennu samples that Brown researchers were involved with, show that the asteroid contains water-bearing minerals, carbon, nitrogen, phosphorous and organic compounds. Now, researchers want to pinpoint and break down that data more thoroughly, quantifying the diversity of its composition.

The Bennu samples RELAB is analyzing look like ground pieces of charcoal to the naked eye and are kept in a specialized sample preparation box under nitrogen so that they will not be altered by oxidation, water vapor or contaminated by dust.

"Our clean room is designed in a specific way," said Takahiro Hiroi, a senior research scientist at RELAB. "The pristine samples must be kept dry enough to prevent water absorption but should not be too dry to cause static electricity. The temperature is just right for us to be comfortable enough but stable for the samples."