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A trio of researchers from the CSIC Universitat de València and Universitat de Barcelona have used data from the Antarctica IceCube detector to measure the mass of the earth. In his paper published in the journal Nature Physics Andrea Donini, Sergio Palomares-Ruiz and Jordi Salvado describe using data describing neutrins passing through the earth to learn more about the interior of the planet. Véronique Van Elewyck with Paris Diderot University has written a News and Views piece about the work done by the team in the same journal edition.
Currently, scientists use calculations based on gravity pressures and readings from seismic detectors to measure the earth’s mass and its density. In this new effort, the researchers have taken a different approach, looking at the number of neutrins that penetrate the planet.
The IceCube Neutrino Observatory was founded in 2005. It consists of thousands of sensors underneath the ice to detect neutrins that have crossed the ground. Neutrins are weakly interacting particles. Those passing through the earth are known as atmospheric neutrins, as they stem from collisions between cosmic rays and the earth’s atmosphere. In this new effort, researchers used data from IceCube from 201
1 to 2012. It was not published publicly until 2016. IceCube detects low energy neutrinoins and high energy neutrines can not make it all the way through the planet.
To calculate the mass of the earth, scientists were measured how much of the neutrino current produced by atmospheric collisions made it through the planet. To calculate the density of the Earth’s layers, they calculated how many neutrinoes could come through the planet at different angles to IceCube.
The researchers report that their findings are consistent with measurements of the planet taken with traditional methods. But they also note that when the years go by and IceCube collects more data, measurements of the planet using neutrinos will be more accurate. Van Elewyck suggests that when other neutrino sensing stations are established elsewhere, it should be possible to conduct a full three-dimensional analysis of the planet that offers information that is not available otherwise.
Possible explanation for the excess of electronutrins detected by the IceCube Neutrino Observatory
Andrea Donini et al. Neutrino Tomography of Earth, Nature Physics (2018). DOI: 10,1038 / s41567-018-0319-1