The edge of the solar system is a blob, 3D map reveals - Livescience.com

Solar wind repels 70% of cosmic radiation, but it doesn't protect every side of the solar system equally.

Despite causing occasional blackouts here on Earth, the solar wind actually does a pretty good job of defending our planet (and the solar system) from the harshest interstellar radiation.

As the wind gusts out of the sun in every direction at once, it forms an enormous protective bubble around the solar system that repels about 70% of incoming radiation, Live Science previously reported.

This bubble is known as the heliosphere, and its edge (called the heliopause) marks a physical border where the solar system ends and interstellar space begins — but, unlike most borders on Earth, scientists have no idea how big it is or what it looks like.

From this travel time, the team calculated how far the wind had blown in a given direction before being repelled by interstellar radiation, allowing the researchers to map the invisible edges of the solar system similarly to the way bats use echolocation, the researchers said.

"Just as bats send out sonar pulses in every direction and use the return signal to create a mental map of their surroundings, we used the sun's solar wind, which goes out in all directions, to create a map of the heliosphere," lead study author Dan Reisenfeld, a scientist at Los Alamos National Laboratory in New Mexico, said in a statement.

In this windward direction, the distance from the sun to the edge of the heliosphere is considerably shorter than it is in the opposite direction — about 120 astronomical units (AU), or 120 times the average distance from Earth to the sun, facing the wind versus at least 350 AU in the opposite direction.