HackVent 2023 - [HV23.05] Aurora

Difficulty: Easy

Category: Fun

Author: monkey9508

The Northern Lights appeared at exceptionally low latitudes this year due to the high level of solar activity. But from Santa’s grotto at the North Pole, it’s not unusual at all to see them stretching across the sky. Snowball the elf tried to capture a video of the aurora for his Instagram feed, but his phone doesn’t work well in poor light, and the results were rather grainy and disappointing. Is there anything you can do to obtain a clearer image?

We get a video with a lot of noise. We can use imagemagick to combine all frames into a single image, taking the mean value:

$ convert aurora.mp4 -evaluate-sequence mean -alpha off aurora.png

This results in:

The flag is: HV23{M4gn3t0sph3r1c_d1sturb4nc3}