Heliosphere model. Magnetohydrodynamical (MHD) model showing how the heliosphere of the Sun interacts with the local interstellar medium (ISM). The Sun (and the orbit of the Earth) is located in the tiny blue region in the center. The ISM is moving from left to right. The colours are scaled to represent temperature, with blue around 10,000 Kelvins, and red over 1,000,000 Kelvins (corresponding to the bow shocked region in the plasma). The green region around the Sun varies in radius between 100-200 astronomical units (AUs).