When two stars collide, they send out a jet of particles that seems to move at seven times the speed of light. However, this is just an optical illusion called “superluminal motion.”

Astronomers have found a huge blast of energy coming from space that seems to be going seven times faster than the speed of light, which is impossible.

When two stars collide, they send out a jet of particles that seems to move at seven times the speed of light. However, this is just an optical illusion called “superluminal motion.”

Astronomers have found a huge blast of energy coming from space that seems to be going seven times faster than the speed of light, which is impossible.

This is, of course, an optical illusion. It is called “superluminal motion,” and it happens when particles come very close to moving as fast as light. In this case, scientists saw a jet of energy shooting out of a place where two stars were colliding at an incredible 99.97% of the speed of light, or about 670 million miles per hour (1.07 billion kilometers per hour).

Near-light-speed particles shoot out of a black hole. A similar jet was just found coming from two neutron stars that were colliding, which seems to go against the laws of physics. (Image credit: NASA Goddard)

Gravitational waves can’t be seen with the naked eye, but they can be found with tools like the Large Interferometer Gravitational Wave Observatory in Pasadena (LIGO). So, when LIGO found the first explosion of waves from two stars colliding in 2017, astronomers from all over the world turned their telescopes on the collision to learn as much as they could about it. Soon after, astronomers saw a high-speed jet of particles shoot out of the place where the two objects collided and light up clumps of matter that were being blasted by the stars.

In their new paper, astronomers used the Hubble Space Telescope from NASA, the Gaia space observatory from the European Space Agency, and six other radio telescopes on Earth to study the jet. Using these measurements, the scientists were able to figure out both the real speed of the jet and the speed that seemed to defy physics.

The illusion of going faster than light is caused by the difference in speed between the particles in the jet and the light particles (or photons) they release. Because the particles in the jet move almost as fast as the light they give off, it can look like particles from the beginning of the jet arrive at Earth around the same time as photons from the end of the jet, making it seem like the jet is moving faster than the speed of light.

This illusion has already been seen in a few other space objects, such as a jet shooting out of the Messier 87 galaxy in the Virgo constellation at almost the speed of light. So far, all examples of traveling faster than the speed of light can be described mathematically in a way that doesn’t go against the laws of physics.