u don't open it .it opens by itself
at the playground on big Nate island
its where the girls were "yakking"
you click it and drag it out
Its in the middle of the playhouse area
You have to beat Big Nate on the ski boats and get the map that is under the rocks. :)
At the end of Big Nate Island, when the Time Capsule is discovered, it seems to not want to come out of the ground. In fact, it never comes completely out of the hole. When you see the shiny "gold" or "brass" button, press it to open the Capsule.
There isn't any time capsule in super power island, only in Big nate island
Ring the school bell.
You just have to click on the yellow thing on the box and it will open
In Nate Island, the girls have moved from their spot so you can dig and find the time capsule.
Artur is in the secret room behind the file cabinet. (He was hunting for the Time Capsule.)
click th gold part in the middle