The first formation of each season is often the simplest. A single circle with a ring around it or a circle with a dot at its centre. We call this the hydrogen signature.
Why hydrogen?
Hydrogen is the simplest and most common element in the universe. One proton at the centre, one electron around it. Draw it in its simplest form and you get a circle with a ring.
Scientists who think about contact with other worlds often name hydrogen as the natural place to start. It is the same everywhere. The Pioneer plaque uses the hydrogen atom as its unit of time and length for exactly this reason.
A greeting
If an intelligence wanted to say hello in a way any scientific species would understand, the hydrogen atom is the obvious choice. A formation like this at the start of each season reads as a greeting before the more complex designs that follow.
The signature also appears inside later formations, such as the signal device diagram of 2000 and the two-stage expansion of 2001, which ties those designs back to the same source.
See the signatures
The hydrogen signature page shows the classic form, from East Oakley in Hampshire in 1996. Browse the hydrogen signature theme for every example in the catalogue.
