Archive · made public 2219-10-05 · 1420.405 MHz
Someone is calling from 11.01 light years away.
On 2219-09-18 every pulsar ledger in the solar system logged the same faint pattern. It comes from Ross 128 b, it was sent on purpose, and it is still arriving.
- Source
- Ross 128 b · M4V
- Distance
- 11.01 ly
- Position
- 11h47m44s +00°48′
- Light left them
- 2209
- Days since
- –
Signal
How it started
The MC ledger keeps its clock by timing pulsars, on every world, all the time. That is why it heard first.
-
A residual nobody expected
The ledger node on the far side of the Moon times twelve pulsars to keep the MC clock. At 03:12 it logged a narrow tone at 1420.405 MHz, the frequency of cold hydrogen, switching on and off. It was filed as local interference.
-
Every other ledger heard it too
Earth, Isidis on Mars and the Ceres node logged the identical pattern, each at a different moment. Ledgers compare notes at light speed, so the comparison alone took most of the day.
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The delays point at one star
The arrival times fit a single wave from one direction outside the solar system: RA 11h 47m 44.4s, Dec +00° 48′ 16″. That is Ross 128, a quiet red dwarf in Virgo, much dimmer than the Sun and about twice as old, 11.01 light years away. In 2017 the Arecibo telescope recorded odd signals from this direction; they turned out to be Earth satellites. This time they are not.
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It is not natural
The pulses are separated by 2, 3, 5, 7, 11 … 47 units: the prime numbers, in order. No pulsar, maser or reflection does that. Then 667 bits follow, and the whole sequence repeats.
-
The transmitter is on the planet
The tone slides up and down by about 260 kHz every 9.87 days, exactly the time Ross 128 b takes to circle its star. The transmitter rides on that planet, and whoever built it did not correct for the Doppler shift. The planet is tidally locked: one side always day, the other always night.
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The 667 bits are a picture
667 is 23 × 29. Folded into rows of 23, the bits make a drawing. Fold it yourself.
-
Made public
Every ledger published its raw recordings on the same day. This page is part of that announcement.
Decode
Fold the beacon
You have the same data the ledgers had. Three steps from noise to a picture.
1 · Count the gaps
The preamble is a row of pulses with prime-numbered gaps. Its only job is to say "this is deliberate".
2 · Read the payload
Then 667 bits, ones and zeros, and nothing to say how they fit together.
3 · Fold it
Lay the bits out in rows. Try different widths; only one makes sense.
Distance
Nobody is coming.
11.01 light years
Not us, and not them. Neither side can build a ship that crosses 11.01 light years, and nothing in the signal suggests they are trying. What crosses is light.
So this is contact by correspondence. A question sent today reaches them on 2230. If they answer at once, the reply lands on 2240. Every exchange takes a generation, and the people who start a conversation may not be the ones who finish it.
- One way
- 11.01 yr
- Round trip
- 22.02 yr
- Distance
- 104.2 trillion km
For now, theirs is the only voice we can hear.
Write back
Write to the star
Your letter travels at light speed, almost 300,000 km every second. Send the link to anyone and they can watch it go.