v2 = 44.72 (100 mph = 44.7 m/s) P = 0.5 * ρ * v2 P = 1224 (pressure in Pa = N/m2) Astrophysical examples of ram pressure Galactic ram pressure stripping Within astronomy and astrophysics, James E. Gunn and J. Richard Gott first suggested that galaxies in a galaxy cluster moving through a hot intracluster medium would experience a pressure of where is the ram pressure, the intracluster gas density, and the speed of the galaxy relative to the medium. This pressure can strip gas out of the galaxy where, essentially, the gas is gravitationally bound to the galaxy less strongly than the force from the intracluster medium 'wind' due to the ram pressure. Evidence of this ram pressure stripping can be seen in the image of NGC 4402. These ram pressure stripped galaxies will often have a large trailing tail and because of this they are commonly called "Jellyfish galaxies." Ram pressure stripping is thought to have profound effects on the evolution of galaxies. As galaxies fall toward the center of a cluster, more and more of their gas is stripped out, including the cool, denser gas that is the source of continued star formation. Spiral galaxies that have fallen at least to the core of both the Virgo and Coma clusters have had their gas (neutral hydrogen) depleted in this way and simulations suggest that this process can happen relatively quickly, with 100% depletion occurring in 100 million years to a more gradual few billion years. Recent radio observation of carbon monoxide (CO) emission from three galaxies (NGC 4330, NGC 4402, and NGC 4522) in the Virgo cluster point to the molecular gas not being stripped but instead being compressed by the ram pressure. Increased Hα emission, a sign of star formation, corresponds to the compressed CO region, suggesting that star formation may be accelerated, at least temporarily, while ram pressure stripping of neutral hydrogen is ongoing. More recently, it has been shown that ram pressure can also lead to the removal of gas in isolated dwarf galaxies that plunge through the cosmic web (the so-called cosmic web stripping process). Although the typical overdensity within the cosmic web is significantly lower than that found in the environment of galaxy clusters, the high relative speed between a dwarf and the cosmic web renders ram pressure efficient. This is an attractive mechanism to explain not only the presence of