The cohesive force of asteroid particles influence microgravity and can be evaluated under several assumptions of particle size and their sensitivity to particle shape. Approximately hundreds of kilograms of material fall on to Earth's atmosphere daily from space, and filter down as tiny grains and fine dust. Many meteorites that reach Earth from space are pieces of asteroids.
Artistic representation of the asteroid-belt between Mars and Jupiter in the solar system. Credit: mopic/shutterstock In a new report now published in Science Advances, Yuuya Nagaashi and a research team in planetology at the Kobe University in Japan, conducted cohesive force measurements of meteorite fragments. The cohesive force of the asteroid particles were orders of magnitude smaller, resulting in the high mobility of asteroid surface particles identified during space exploration. For astrobiologists interested in the earliest history of Earth and the solar system, these particles that have survived almost unaltered offer significant information of the earliest period of the solar system's history. Cohesive force of particles. (A) Measured cohesive force of Allende and Tagish Lake meteorite fragments, prepared by a mortar and pestle or projectile impact, against a smooth glass slide under ambient conditions. The fitted curves were obtained on the basis of Eq. 3 in the article. (B) Measured cohesive force of tens-of-micrometer– and micrometer-sized Allende fragments against a stainless steel slide under ambient conditions. The value of the large fragments is approximately twice greater than that against the glass slide in (A), which might be consistent with the trend that the Hamaker constant of metals is greater than that of silica. (C) Schematic diagram of the contact states of meteorite fragments of different sizes against slides inferred from the cohesive-force measurements. The left fragment represents tens-of-micrometer–sized fragments at 1 gE, the middle fragment represents micrometer-sized fragments at 1 gE, and the right fragment represents micrometer-sized fragments at 8 × 104 gE. (D) Comparison of the measured cohesive force of aggregates tens of micrometers in size consisting of submicrometer-sized silica spheres against a glass slide under ambient conditions and the cohesive force estimated by the relationship obtained for the micrometer-sized…