# One Light Day — Voyager 1 · One Light-Day

> Voyager 1 · One Light-Day (iPhone/iPad app by Jean Marc Moro.)

- Source: https://appshunter.io/ios/app/one-light-day/id6797285165 (this page in markdown: same URL + `.md`)
- Developer: [Jean Marc Moro](https://appshunter.io/developer/1896481117)
- Category: Education, Reference
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 18.0 · 15 MB
- Languages: American English
- Released: 2026-08-20
- Data updated: 2026-08-26
- User reviews in markdown: https://appshunter.io/ios/app/one-light-day/id6797285165/reviews.md

## What is One Light Day?

One Light Day is a free digital monument celebrating Voyager 1, humanity’s farthest spacecraft.
On 18 November 2026, Voyager 1 is expected to reach a remarkable symbolic milestone: a distance from Earth that light takes approximately twenty-four hours to cross.
One Light Day transforms that immense distance into a personal and interactive experience.
DISCOVER THE JOURNEY
Follow Voyager 1 from its 1977 launch, past Jupiter and Saturn, through the heliopause and into interstellar space.
EXPERIENCE THE DISTANCE
See its estimated distance from Earth, one-way light time and the countdown to the one-light-day horizon.
MEET VOYAGER 1
Examine and interact with a detailed 3D model of the spacecraft that has travelled farther than any other human-made object.
EXPLORE THE GOLDEN RECORD
Discover the sounds, images, greetings and scientific symbols selected to represent Earth to the cosmos.
FIND VOYAGER IN THE SKY
Use your iPhone’s location and motion sensors to face the estimated direction of Voyager 1.
SEND A SYMBOLIC LIGHT
Begin with prime numbers, then encode a short human word as flashes of light. After sending it, follow a twenty-four-hour chronograph representing the photon’s journey.
A FREE EXPERIENCE
One Light Day contains no advertising and requires no subscription. Every experience is available to everyone. Optional contributions help maintain the app and its website but never unlock additional functionality.
Voyager 1 will remain humanity’s farthest pioneer, our avant-garde in interstellar space.
One Light Day is an independent educational, cultural and artistic tribute. It is not affiliated with or endorsed by NASA or JPL. Scientific distances, directions and times are estimates and are not real-time telemetry.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Small Signal | $0.99 | one-time |
| Bright Signal | $1.99 | one-time |
| Farther Signal | $2.99 | one-time |
| One Light Day | $4.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-08-20

No release notes.

## More apps by Jean Marc Moro

- [NEXUS Protocol](https://appshunter.io/ios/app/nexus-protocol/id6767498503)
- [Signal Ark: SETI Explorer](https://appshunter.io/ios/app/signal-ark-seti-explorer/id6784939271)
- [Brutal Spanish](https://appshunter.io/ios/app/brutal-spanish/id6790445194)
- [Synapse IQ Forge](https://appshunter.io/ios/app/synapse-iq-forge/id6793995746)
- [Baggage Trace](https://appshunter.io/ios/app/baggage-trace/id6794618965)
- [Vertical DNA](https://appshunter.io/ios/app/vertical-dna/id6796605350)

All apps by Jean Marc Moro: https://appshunter.io/developer/1896481117

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-26.*