History from the side of those it happened to
On this day — August 17
| Date | Country | Category | Title |
|---|---|---|---|
| 17 August 1877 | United States | Astronomy | Asaph Hall discovers Phobos |
| 17 August 1877 | United States | Astronomy | Mars's second satellite is recorded |
| 17 August 1877 | United States | Astronomy | Phobos is found closer to Mars |
| 17 August 1877 | United States | Astronomy | The Martian system becomes a three-body subject |