What is the meaning of Interstellar ?

Here’s an article about deep space, and here’s an article about interstellar space travel.

For NASA, it's official: Voyager 1 has entered interstellar space. But given the many false alarms over the years, what makes scientists so confident now?

This time, researchers have used several clues about plasma changes around Voyager 1 to determine

that it entered interstellar space around Aug. 25, 2012. NASA announced that Voyager 1 has arrived in interstellar space on Thursday (Sept. 12).

We looked for the signs predicted by the models that use the best available data

Unfortunately, the 36-year-old spacecraft's plasma detector broke in 1980.

The team expected to see a shift in the direction of the magnetic field at the boundary between interstellar space and the heliosphere.

They also expected to see a sharp drop in the presence of charged particles from the sun and a rise in cosmic radiation from interstellar space.

April 2013 scientists remembered that Voyager I had experienced bursts of radio waves in 1983 to 1984 and in 1992 to 1993 when interstellar plasma was bombarded with a huge blast of solar material.

They expected to find similar oscillations once Voyager was jolted by interstellar plasma.

On April 9, they noticed those oscillations, which likely occurred a year before due to a solar storm around St. Patrick's Day..

The oscillations got bigger, indicating that Voyager was entering the much denser plasma of interstellar space.

Most of the clues indicated that Voyager 1 was indeed surrounded by interstellar space.

Therefore, interstellar panspermia events are related to the average density of stellar systems containing habitable planets.