Contact Mystery Cache

One of my all time favorite movies is "Contact" with Jodie Foster.

Like in that movie, we have received a message from a far away planet.
That message provides coordinates to a cache where you can log that you have received and understand the message.

The alien planet orbits it's star at about the same distance as Jupiter in our own solar system.  Therefore, it is theorized that these aliens have far better eye sight than we do in low light, but that they only see in black and white.

Decode the message and sign the log so the alians know you hear them.

Cache contains the alien log only, bring your own pen