Shape of our solar system more like a deflated croissant than a comet's tail, NASA study shows

Scientists from the National Aeronautics and Space Administration (NASA) have developed a new prediction about the shape of the bubble the surrounds our solar system. The space agency has said all planets of our solar system are encased in a magnetic bubble that is created by the solar wind. For years scientists have tried figuring out the shape of the bubble that travels through space as the Sun orbits the centre of the galaxy. While traditionally scientists thought that the heliosphere as a comet shape with a rounded leading edge and tail, new research has showed that the bubble is actually shaped like a deflated croissant, lacking a long tail. The heliosphere is the solar system’s shield against the rest of the galaxy. [caption id=“attachment_8691751” align=“alignnone” width=“1280”] The shape of the Sun’s bubble of influence, the heliosphere (in yellow), may be shaped like a deflated croissant rather than the long-tailed comet shape it is thought to be. Image credit: Opher et al/Nature Astronomy[/caption] To study the boundary of interstellar space, scientists have been capturing and observing galactic cosmic rays flying towards our planet from different parts of the galaxy along with existing ones. These particles travel out towards the heliosphere and are bounced back by a series of electromagnetic processes. Scientists under NASA’s Interstellar Boundary Explorer (IBEX) used these particles as radar to know our boundary to the interstellar space. Merav Opher, lead author of the new research, stated, “There are two fluids mixed together. You have one component that is very cold and one component that is much hotter, the pick-up ions.” [caption id=“attachment_8691761” align=“alignnone” width=“1280”] Some research suggests that the heliosphere has a long tail, much like a comet, though a new model points to a shape that lacks this long tail. Image: NASA’s Scientific Visualization Studio/Conceptual Imaging Lab[/caption] He went on to add that if one has some cold and hot fluid, and they are put in space, they won’t mix. Instead, Opher said that they would evolve mostly separately. The scientist said what they did was to separate the two components of the solar wind and model the resulting 3D shape of the heliosphere. Opher said that since the pick-up ions dominate the thermodynamics of the universe, objects in the universe are mostly spherical. Since they leave the system extremely quickly beyond the boundary marking the outer limits of the Sun’s influence, called the termination shock, the whole heliosphere deflates. The study was published in Nature Astronomy in March. It subsequently got featured as the cover story in the journal’s July issue.