Terry Jacobson escorts glacial rebound researchers to Eldred Rock in the late 1990s. Photo courtesy of Terry Jacobson.

There’s an empty slip in the small boat harbor that Terry Jacobson can’t help but feel a little sentimental about. The slip housed his 46-foot power barge “Arcturus” for more than two decades. Last September he sold it.

“Just yesterday I was looking down at that empty slip,” Jacobson said this week.

Named for the brightest star…