Radio telescope

The dish, the radio map and the waterfall: how to tune the receiver to signals from the sky.

Stars are joined with lines, seams are traced with the crosshair, vents are heard in rhythm — and radio is tuned. The radio telescope shows no sky: at the top is a radio map, below it the waterfall: frequency left to right, time top to bottom.

Assembly

Radio Receiver sits on a mast of three Lattice Mast, and around the receiver, at its level, a 7 × 7 dish of Dish Panel. The receiver shows missing blocks as ghosts, and the last block placed assembles the dish by itself. The dish looks where it was aimed and keeps tracking that point across the sky.

The radio telescope dish: the beam of a find at dusk

A real sky

The map is the real Galaxy: the disc and the bulge, bright sources at their real coordinates. What never rises over Earth can be seen from the Moon or from your own station. Running machines closer than 24 blocks and thunderstorms cause interference — put the dish away from your base.

Hands-on

Every kind of signal has its own tuning control — the beam panel tells you which one to take, but not the solution.

Spoiler: this reveals part of the walkthrough.

Narrow band — lead the crosshair along a drifting line, and tune out the interference creeping toward it with the second button.
Dedispersion — the wheel shifts the waterfall until the arc of a burst straightens into a line; record it while the burst is visible.
Folding — the wheel changes the trial period: far from the right one there is noise, closer — slanted strokes, exactly right — a pillar.
Template — drag a comb of lines along the spectrum to the faint lines; they show once the dish has gathered enough signal.

Everyone around sees a find: the dish shoots a beam into the sky in the color of the source.

Folding: the period is still off — slanted streaks

Template: the comb of lines on the quasar spectrum

Narrow band: the signal trace on the waterfall

The repeating source

Almost every fast radio burst comes once. One source — in Vulpecula — repeats: once in five days it sends a series of three to six bursts in a night (the hint “when will the signal come” counts down to it). Point the dish at Vulpecula and straighten the arcs with the dispersion wheel.

Spoiler: this describes a place reached late in the game.

A burst from Vulpecula: the wheel straightens the arc into a line

The three-road interferometer

Three radio telescopes on three roads — in the Solar System, in the Interrift and in the Depths — listen as one eye once they are tied together by hydrogen clocks. Build a Hydrogen Maser from the blueprint (Interferometer Blueprint) and set it beside the receiver of an assembled telescope.

Every four days comes the night of Sagittarius (a day and a half long); outside it the maser console says when the next one begins. On the night press the maser and keep the crosshair on the drifting bright center for a minute — on every road it moves in its own way. You get a Night Record.

Spoiler: this lists rewards.

What next

From orbit the whole sky is visible: “Ships and space”.
Radio logs feed research projects: “Station Observatory”.
Where the navigation records lead — “Interstellar space” (behind a spoiler).

AssemblyCopy Anchor Link

A real skyCopy Anchor Link

Hands-onCopy Anchor Link

The repeating sourceCopy Anchor Link

The three-road interferometerCopy Anchor Link