Comet dust has been discovered in Antarctica, marking the first time the elusive material has been found on Earth. The alien material was found preserved in ice and snow.
Comets were formed at the same time as the solar system, and still contain some of the oldest material available anywhere in our local family of planets.
Dust from comets could only be collected using airplanes flying at high altitudes, or by sending spacecraft out to the frozen bodies. Flights lasting hours typically collect just a single particle of the material, making the process slow, arduous, and expensive. Collecting this material from ice and snow in Antarctica offers a new way of gathering samples of comets.
"It's very exciting for those of us who study these kinds of extraterrestrial materials, because it opens up a whole new way to get access to them. They've found a new source for something that's very interesting and very rare," Larry Nittler, from the Department of Terrestrial Magnetism at the Carnegie Institution for Science, said.
Gathering larger quantities of dust will allow researchers to conduct additional experiments not possible with the sample samples sizes available today.
"I think it could precipitate a paradigm shift in the way these kinds of materials are collected," John Bradley from the Hawaii Institute of Geophysics and Planetology of the University of Hawaii, Manoa, stated in a press release.
Cometary dust collected in Antarctica is also cleaner than material gathered by aircraft. That process involves gathering the dust on plates coated with silicon oil, trapping the extraterrestrial material like a fly in a spider's web. This coating, and organic compounds used to clean the plates, can contaminate the samples, interfering with experiments designed to detect organic molecules. Researchers hope to be able to compare analysis of samples from the Antarctic with those gathered in the stratosphere. This study could make it possible to determine which components of samples were formed in space, and which are contaminants.
Researchers collected snow and ice from two locations in Antarctica, over the course of several years, starting in 2000. This material was melted down, and samples of contaminants were examined, yielding over 3,000 micrometeorites. Each of these tiny objects were examined under a stereomicroscope over five years of study. Over 40 of the minuscule meteorites were found to exhibit qualities that marked them as possible remnants of comets.
Some astronomers believe comets may have brought massive quantities of water to the ancient Earth, and possibly the first complex organic compounds which may have sparked life.