PASADENA, CALIFORNIA — The Voyager spacecraft have found that space is more dense outside the Solar System, according to research published in the journal Astrophysical Letters. NASA’s Voyager 2 crossed into interstellar space in November of 2018 after a 41-year voyage. Its twin, Voyager 1, entered interstellar space at a different location in 2012. The authors of the study write that the increase in density detected by the Voyager spacecraft could be due to interstellar magnetic fields becoming stronger as they approach and drape over the heliopause. Alternatively, the material blown by the interstellar wind might slow down and build up as it approaches the heliopause. More data is needed from the two Voyagers to try to untangle this mystery. However, as the authors of the study note, “It is not certain whether the Voyagers will be able to operate far enough to distinguish between these two classes of models.” SOURCES: Astrophysical Letters, Nature Astronomy, NASA, The Atlantic, Space.com https://iopscience.iop.org/article/10... https://www.nature.com/articles/s4155... https://www.nasa.gov/mission_pages/su... https://www.jpl.nasa.gov/news/news.ph... https://www.theatlantic.com/science/a... https://www.theatlantic.com/science/a... https://www.space.com/37775-nasa-voya...