Earth's Velocity to Millimeter per Hour

Earth's orbital velocity around the Sun is approximately 29,765 m/s (29.8 km/s), the speed at which our planet travels through space.

v = 2πr/T where r is Earth's orbital radius (~150 million km) and T is one year. Result: ~29.8 km/s.

To km/h: × 3,600. To mph: × 66,600. 29.8 km/s = 107,280 km/h = 66,660 mph.

Interplanetary mission Δv calculations, understanding Earth's motion, and cosmic velocity references.

We're all traveling at ~30 km/s around the Sun right now. In one second, Earth moves 30 km — about 19 miles!

Forgetting about Earth's motion when calculating interplanetary trajectories — it provides free velocity!

~30 km/s around the Sun. We travel 940 million km per year at this speed. Missions to other planets add/subtract from this.

Millimeter per hour measures extremely slow movements in millimeters over an hour. Used for minute geological and material changes.

1 mm/h = 0.001 m/h = 0.0000001 km/h = 0.000000278 m/s.

To m/s: ÷ 3,600,000. To cm/h: ÷ 10. To m/h: ÷ 1,000.

Cave formation rates (stalactite/stalagmite growth), extremely slow material creep, and long-term geological monitoring.

Stalactite growth: 0.1–1 mm/h in active caves. Human hair growth: ~0.015 mm/h. Fingernail growth: ~0.004 mm/h.

Using for anything except the slowest processes. Confusing with mm/min (60× faster).

1,000 mm/h = 1 m/h. Extremely specialized unit. Think geological time scales.