Editor's Note: University of Southern California geobiologist Katrina Edwards is taking part in a three-week drilling project at the Atlantic's North Pond—a sediment-filled valley on the ocean floor—designed to locate and study what she calls the “intraterrestrials”: the myriad microbial life-forms living inside Earth's crust. This is her twentieth blog post. To track her research ship's current position, click here. To see all her posts, see "60 Seconds in North Pond."

35,000 FEET ABOVE THE ATLANTIC (March 13, 2009)—I sit here simply blasted tired.

Decorated in bruises from head to toe, stuck with a vaccination for yellow fever in my arm, a few pounds lighter, overwhelmed with the collective experiences of the past month, I wonder how in the world I'm going to get recalibrated to non–sea life again.

But undeniably I'm also very, very happy, and very sad at the same time. I'm elated at the success of the cruise and, most importantly, about the great team we had out there and with whom I'll work with for years to come.

As for the sadness, I think Wolfgang Bach said it best, en route to the airport (for the second time), when he noted that though he was excited about going home, he was mourning that it was "already" over, and that the unique scientific group that had come together was dispersing so soon.

The North Pond journey has begun. Danke for your interest in this research cruise and stay tuned for news about North Pond, a deep, dark place that will set a new standard for research on the intraterrestrial inhabitants of the Earth's crust.