This artist's concept shows the surface of a neutron star cracking up under internal stresses, creating a powerful outburst of energy. A neutron star is the crushed core of a once-mighty star, and its surface consists of a thin layer of ultradense iron. A "starquake" on its surface may also be triggered by interactions with a companion object. [Darlene McElroy/LANL]
Earth’s crust sometimes “cracks,” causing earthquakes and other deadly events. Yet these events are puny compared to what happens when the crust of a neutron star cracks. That can release more energy than millions of normal stars.
A neutron star is basically a big atomic nucleus spinning through space. Gravity has squeezed it so tightly that a cupful of its material would weigh billions of tons. It’s topped by a thin crust of iron that’s not quite as dense as the material below it.
A study by David Tsang of Caltech says that if two neutron stars are about to merge - or a neutron star and a black hole - the neutron star’s crust should break up in the final seconds before the merger.
As the two objects spiral together, tides on the neutron star’s surface get stronger, pulling and stretching the crust. The crust cracks, sending seismic waves bouncing through the star. The waves get so intense that they shatter the crust. That energy then feeds into the neutron star’s magnetic field, producing a fireball - moments before the star is destroyed in the collision.
Studying such an event would reveal important details about the crust, and about the transition zone between the crust and the star’s core. Such studies would require a way to measure gravitational waves - something that’s not possible right now. But advances in technology could change that - allowing scientists to probe the nature of some of the most bizarre objects in the universe.
Script by Damond Benningfield, Copyright 2013
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