Matter, dark matter, and dark energy are distributed homogeneously throughout the universe over length scales longer than 300 million light-years (ly) or so. However, over shorter length-scales, matter tends to clump hierarchically; many atoms are condensed into stars, most stars into galaxies, most galaxies into clusters, superclusters and, finally, large-scale galactic filaments. The observable universe contains as many as an estimated 2 trillion galaxies and, overall, as many as an estimated 10 stars – more stars (and earth-like planets) than all the grains of beach sand on planet Earth ; but less than the total number of atoms estimated in the universe as 10 ; and the estimated total number of stars in an inflationary universe (observed and unobserved), as 10. Typical galaxies range from dwarfs with as few as ten million (10) stars up to giants with one trillion (10) stars. Between the larger structures are voids, which are typically 10–150 Mpc (33 million–490 million ly) in diameter. The Milky Way is in the Local Group of galaxies, which in turn is in the Laniakea Supercluster. This supercluster spans over 500 million light-years, while the Local Group spans over 10 million light-years. The universe also has vast regions of relative emptiness; the largest known void measures 1.8 billion ly (550 Mpc) across.