Home / Science / America's 250th Time Capsule Sealed
America's 250th Time Capsule Sealed
2 Jul
Summary
- A 900-pound time capsule sealed with a bell jar was buried.
- Objects from all 50 states and six territories are inside.
- Engineers created a controlled environment to preserve items for 250 years.
As America approaches its 250th anniversary, a significant time capsule was interred at Independence National Historical Park in Philadelphia. This endeavor, overseen by the National Institute of Standards and Technology, involved meticulous engineering to ensure the capsule's contents survive for a quarter of a millennium.
The capsule itself is a 900-pound stainless steel cylinder, eight feet underground, protected by an 1,100-pound bell jar. It houses over 200 items representing all 50 states and six territories. These diverse submissions include a message etched on whalebone from Maine, copper from Arizona, and fabric from the Wright brothers' original flight from Ohio.
To preserve these varied artifacts, engineers created a unique internal environment within the capsule. Items were stored in a humidity cabinet at 35 percent humidity and 23 degrees Celsius before sealing. This controlled atmosphere, maintained by a three-quarter inch thick stainless steel wall and an indium wire seal, is designed to prevent degradation until its scheduled opening in 2276.
