Reapers are coming after me in a star system. How do I reset the meter?

After scanning a few planets in a star system, the Reaper bar fills up and they start coming after me. When will that bar resets so I can have access to the system again?

You have to do one mission, and all systems get their reaper awareness meter reset.

To make the most out of this you should visit all systems you haven't explored to 100% yet before going onto a mission, that way you get the maximum number of tries overall.

There is also the trusty old save and reload method here, just save before scanning and then scan down everything in one system. Let yourself be eaten by the reapers, reload and only scan exactly where you know the signatures are. That way you often don't alert the reapers at all, or if you do you're already close to the signature and can just pick up whatever there is and quickly get out of the system. While you're in orbit around a planet the star system map is paused, so you can even do that with the reapers on your trail.

To find the signatures that are not on planets without alerting the reapers you can also just fly around in space a bit and wait until you hear the sound effect you get when you fly near a planet. If you get that effect while not near a planet it means that there is a scannable signature nearby. This can reduce the number of scans you need and help you avoid alerting the Reapers.

You just have to do any 1 mission and it resets. But i found that its pretty easy to just clear the galaxies while you are being chased by them