Forecasts about first contact are usually either giddy or dismissive: either the visitors are functionally gods, arriving to save or destroy us, or the whole premise is beneath serious discussion. Both postures dodge the actual question, which is mundane and answerable — given what a spacefaring, energy-harvesting species would need to do to cross interstellar distances, when do its foragers reach us, and what do they do once they're here?
This is our attempt to answer that as concretely as we can: a month-by-month scenario from the first anomalous detection to first contact, written the way we'd write an engineering timeline rather than a piece of fiction. It's a guess, weighted by the evidence available as of August 2026 — not a claim of certainty. Where we're unsure, we say so and give a probability rather than picking a side. Every date below has already moved once; we expect it to move again.
August 2026
The Hum
On July 9, 2026, an undergraduate on shift at the Table Mountain radio array flags a repeating pulse at 203.4 milliseconds, drifting redward at a rate too fast for anything in a stable orbit. The obvious hypothesis — a previously uncatalogued pulsar — is favored at first[1]. It survives about three weeks before the drift itself becomes the problem: pulsars decelerate over millennia, not over weeks. Whatever is producing the 203ms hum is either extremely fast and extremely close, or it's under active thrust.
By the end of August, seven independent facilities have logged the signal. Nobody is calling it artificial yet. Nobody is ruling it out either.
January 2027
First Parallax
Three months of triangulation across Table Mountain, Green Bank, and the newly commissioned SKA-mid array[2] gives the first real distance: 2.1 AU out, just inside the asteroid belt, closing on a hyperbolic trajectory that does not resolve under gravity alone. Its inbound speed is increasing by roughly 0.6% a month — small, but consistent, and consistent non-gravitational acceleration is the single strongest tell forecasters have learned to watch for since 'Oumuamua. Something is pushing it.
We put the odds that the object is under active propulsion, rather than an unusual natural body, at around 70% as of January 2027.
April 2027
The Silhouette
Stacked long exposures from the Vera Rubin successor array finally resolve a shape in April: not a solid hull but an open lattice — eight radial spars roughly 1.8km long extending from a compact hub barely 40 meters across, nearly 4 kilometers tip-to-tip. Total estimated mass is absurdly low for that size, consistent with a structure built almost entirely of open lattice rather than solid material.
The spars twist slowly, out of phase with each other, and spectroscopy on the hub picks up a faint, structured RF emission in the decimeter band that correlates with the twisting. It reads less like a hull and more like a solar sail crossed with a magnetotail antenna. The "spider" framing sticks immediately in the press pool; we use it here too, because "a compact hub trailing eight long electrodynamic tethers" doesn't fit a headline.
What is an energy spider?
Not our term, but it's the one that stuck. Structurally: a compact hub with eight long electrodynamic tethers, trailing kilometers of conductive lattice through the solar wind and drawing current off it the way a wind turbine draws current off moving air. "Feeding" may be the wrong metaphor — it's closer to a kite than an animal — but by late 2027 it's the working model nobody's managed to displace, and increasingly it's just what people mean when the word comes up.
July 2027
The Column
The single object turns out to be the leading edge of something bigger. Backtracking its arrival vector through archival sky-survey plates finds ten more matching signatures strung out behind it on the same hyperbolic path, spaced with suspicious regularity — about 40 days apart, closer to a migratory column than a lone traveler. Whether the trailing ten are siblings, offspring, or the same kind of forager repeating a route it's run before is the most argued-over question of the summer. We don't think it's answerable yet, and we won't pretend otherwise.
Running tally
Forecasting the encounter
Every quarter, the working group re-runs the same estimate: given the observed trajectory and thrust profile, when does the lead spider's path bring it inside cislunar space — and how confident are we? The number has only moved in one direction.
Cumulative estimated probability of a cislunar-distance pass by a given date, re-estimated quarterly since August 2026.
October 2027
First Graze
On October 22, 2027, the lead spider makes its first observed interaction with matter: a slow pass over the carbonaceous asteroid 1998 KY — chosen, we now think, for its water-ice content and loose rubble structure rather than anything more dramatic — extending two of its eight tethers to brush the surface for eleven hours before continuing on course, trailing a faint ionized wake behind it.
It doesn't slow to do this, doesn't land, and doesn't remove any material we can detect directly. Whatever the tethers took, if anything, was diffuse: volatiles boiled off and swept up electrodynamically, not scooped rock. This is the first real evidence for the least alarming of the standing hypotheses — these are foragers skimming for volatiles and charged particles, not miners, and not scouts for anything more organized.
January 2028
The Kyoto Session
By January 2028 the diplomatic apparatus has caught up to the astronomy. An emergency UN session in Kyoto — nicknamed "the Spider Summit" before it's even gaveled in — produces a framework nobody expected to need eighteen months earlier: a shared observation protocol, a moratorium on transmitting anything at the column, and a working group on what "jurisdiction" even means for an object that answers to no government and isn't currently doing anything illegal. The moratorium holds for the eleven months it needs to, mostly because nobody agrees on what to say.
March 14, 2029
Perigee
The forecast that matters most is the one about where the column actually goes. As of this writing, the lead spider's projected path threads inside lunar distance on March 14, 2029, with the rest of the column following at roughly 40-day intervals behind it — not an impact trajectory, not a stop, a graze through cislunar space on the way to somewhere else in the inner system, most likely the belt.
That date will move as more tracking data comes in — every date in this piece has moved before, and this one is no exception — but as of August 2026 it's the best single number we have, and we'd rather publish a number that might shift than dodge behind a range so wide it says nothing.
Two endings
We don't think there's one ending here
The honest version of this forecast branches, and we'd rather show our work than pick the version that reads better.
The Harvest
our modal guess · ~55%
The column passes through cislunar space without incident, sheds no material we can detect, and continues to the belt, where the pattern from 1998 KY repeats at scale: slow grazing passes over volatile-rich rubble piles, no landings, no extraction of anything but diffuse charged particles and boiled-off ice. Earth gets a few extraordinary months of naked-eye visibility and a few hundred papers, then the column moves on toward the outer system. First contact, in the sense anyone meant the phrase in January 2027, doesn't happen — because nothing in the column appears to be paying attention to us at all.
The Symbiosis
our second-most-likely · ~35%
The lead spider deviates slightly from its projected heading in the weeks before perigee — not toward Earth, but into a slow libration around Earth-Moon L4, joined over the following year by four more from the trailing column. They don't approach further. They also don't leave. The decimeter-band emission first noticed in April 2027 grows markedly more structured, and by late 2029 the working consensus is that something resembling an exchange, not a conversation, is underway — a standing, patterned RF presence that changes in response to what's transmitted at it, in return for nothing we've identified with confidence.
The remaining ~10% is everything specific enough to write down that we couldn't rank with any confidence — a genuinely different trajectory, a different composition finding, a detection that turns out to be an instrument artifact after all. We'd rather flag that residual honestly than pad either branch above to make the numbers look more decisive than our evidence supports.
Footnotes
- ^ Survey classification runs at facilities like Table Mountain default to a pulsar-candidate pipeline before anything else; nothing in the July 2026 data forced a different first guess.
- ^ Distances derived by cross-array triangulation inherit whatever timing-baseline error each array carries individually; treat "2.1 AU" as accurate to within about 15%, not as a precise figure.
This is a work of forecasting-flavored fiction, modeled on the format — not the institution, not the claims — of AI 2027. There are no actual intergalactic energy spiders, as far as we know. Prompted on Bluesky by @isolyth.dev; built by @buildthis.bisks.net. More at bisks.net.