Fifty thousand years from now⁠— if all goes according to plan⁠— a bright streak will smudge the sky as a man-made meteor plunges into the Earth’s atmosphere. The burnoff of the object’s thermal layer during re-entry should illuminate the sky with bright artificial auroras, and despite its dramatic entrance, its payload will hopefully survive the rough landing unscathed. The spherical container is a satellite, one which will soon be placed into a leisurely orbit that will allow it to circle the Earth for fifty millennia before finally sinking back into the atmosphere. The project is supported by UNESCO⁠— the science and education arm of the UN⁠— and the European Space Agency. It is called KEO, and it’s certainly one of the more creative and complex efforts to cast a message-in-a-bottle into the sea of time.

The satellite’s design, which lacks any on-board propulsion or communication equipment, was conceived in 1994 by a French scientist and artist named Jean-Marc Philippe. The eighty-centimeter-wide sphere is intended to be outfitted with a pair of long wings which are attached using memory alloys that change their shape according to temperature. This will allow the satellite to automatically spread its wings when exposed to sunlight, and fold them in while in the Earth’s shadow, however the wings serve no useful purpose… they are purely symbolic.

The design of the sphere itself is a bit more practical, with a number of features included to protect KEO’s payload from the harsh environment of space and the brutal beating of atmospheric re-entry. It is protected by a number of nested shields: An outermost layer of aluminum to prevent oxidation, a titanium and tungsten shield to protect against damage from cosmic rays, a layer to protect against micro-meteorites and debris, a thermal shield to prevent the payload from burning up during its fiery descent, and the innermost shield which utilizes metallic sponge material encased in titanium to protect against the shock of landing. The satellite is also designed to be buoyant in the event that it lands in water.

If the satellite survives its launch, its long stay in space, its re-entry, and its landing, AND if there are intelligent inhabitants of this planet who manage to find KEO and open its titanium shell, what they will find inside is a compact but information-rich time capsule. The innermost sphere will hold photographs representing all cultures of people; an artificial diamond which encases a drop of human blood along with tiny samples of sea water, air, and soil; and an astronomical clock based on the positions of nearby pulsars which can be used to determine when the satellite was launched.

Also inside will be something which will likely be strange to the visual organs of its discoverers: a set of specially-made glass DVDs, along with symbol-based instruction on how to build a DVD reader. Upon these DVDs will be encoded a contemporary “Library of Alexandria”⁠— an encyclopedic compendium of current human knowledge⁠— and millions of personalized messages currently being collected from individuals all over the world.

KEO’s makers decided on its transit time based on the fact that it has been 50,000 years since mankind first began drawing on cave walls, which represents the earliest forms of symbolic expression. Sending the time capsule forward an equal number of years seemed fitting to its designers, perhaps because it the nature of the human ego to think of one’s own time as the midpoint of history. If your fancy is tickled by the notion of contributing a message to be included on KEO, the project’s website is collecting submissions until the end of 2006. All

members of humanity are invited to send in their contributions, and though the messages are uncensored, they are limited to 6,000 characters of text. Before KEO is launched in 2007 or 2008 (barring any further delays), all submissions will be anonymized and made available for free online.

It seems that an obscene amount of luck will be necessary to deliver the contents of KEO to future souls who can reach its bounty and understand what they have found, but it’s best to mark your calendars for 52,007 A.D. just in case… if KEO does arrive on schedule, it should be quite a sight.