Sitting here on our little blue ball, it’s hard as hell to get even a little understanding on how vast the cosmos actually is. Now, it turns about that our own galaxy is linked to its smaller satellite galaxies by an enormous magnetic field. Excerpt:
For the first time, astronomers have detected a magnetic field associated with the Magellanic Bridge, the filament of gas stretching 75 thousand light-years between the Milky Way Galaxy’s nearest galactic neighbors: the Large and Small Magellanic Clouds (LMC and SMC, respectively). “There were hints that this magnetic field might exist, but no one had observed it until now,” says Jane Kaczmarek, at the University of Sydney, and lead author of the paper describing the finding.
“Not only are entire galaxies magnetic, but the faint delicate threads joining galaxies are magnetic, too,”said Bryan Gaensler, Director of the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, and a co-author on the paper. “Everywhere we look in the sky, we find magnetism.”
“In general, we don’t know how such vast magnetic fields are generated, nor how these large-scale magnetic fields affect galaxy formation and evolution,” says Kaczmarek. “The LMC and SMC are our nearest neighbours, so understanding how they evolve may help us understand how our Milky Way Galaxy will evolve. Understanding the role that magnetic fields play in the evolution of galaxies and their environment is a fundamental question in astronomy that remains to be answered.”
Visible in the southern night sky, the LMC and SMC are dwarf galaxies that orbit our home galaxy and lie at a distance of 160 and 200 thousand light-years from Earth respectively.
Think about those distances. 160 thousand light years is 9.405801e+17 miles – that’s 940,580,100,000,000,000 miles.
That’s a pretty good hike.
Our Milky Way galaxy contains somewhere between 100 and 400 billion stars. Moving out past the Magellanic clouds, we have the Local Group, a group of 54 galaxies with a gravitational center somewhere between our galaxy and the Andromeda galaxy. The galaxies of the Local Group cover about 10 million light years, and are bound together by a webbing of hydrogen and a few single stars.
The Local Group is part of the Virgo Supercluster, a massive structure of 100 groups of galaxies like the Local Group, and spans about 33 megaparsecs – that’s 110 million light years.
The Virgo Supercluster is part of the Laniakea Supercluster, which contains about 300 to 500 clusters the size of the Virgo Supercluster, and spans 160 megaparsecs, or 520 million light years. And the Laniakea Supercluster has as its cosmic neighbors the Shapley Supercluster, Hercules Supercluster, Coma Supercluster and Perseus-Pisces Supercluster.
Problems closer to home occupy most of our waking thoughts and that’s as it should be, but once in a while a little cosmic perspective is in order.