The event, called GW170817, is a so-called neutron star binary merger. Neutron stars are the collapsed cores of once massive stars and are among the densest objects in the universe. According to NASA, just one teaspoon of such a star would weigh four billion tons on Earth.

The massive gravity associated with this mind-blowing density—enough to cause two of these neutron stars to collide in an explosive collision that hurls gravitational waves and gamma rays into space—makes scientists the first to detect both as the result of a neutron star. merger. vision.

The Hubble Space Telescope watched two neutron stars collapse into a black hole after the explosion. A spinning disk then formed around the black hole, which spewed incredibly fast jets of matter into space. By combining their findings with those of the US National Science Foundation, the scientists were able to reproduce the event with remarkable accuracy, including the speed at which the jets were moving.

faster than light

At first, Hubble’s observations showed that the jets were moving at seven times the speed of light. Of course, this is impossible. Scientists explain this discrepancy with a well-known phenomenon: superluminal movement. Essentially, as the jet approaches our planet at nearly the speed of light, the light it emits at later points travels a shorter distance each time, making it appear to be moving faster than it actually is.

After doing some additional calculations, the scientists determined the true speed: at least 99.97 percent of the speed of light – which is actually very fast.

The scientists hope that their findings, published in the journal Nature, will lead to more precise observations of neutron star mergers in the future, potentially helping to calculate the expansion rate of the universe.