200 Km/s

Today, we are able to obtain accuracies in time keeping down to 1 second accuracy in 10s of billions of years but the question is why do we need such precision in relation to interplanetary colonization?

The answer is three dimensional movements through space, calculating transit time and distance and the differing sidereal time as well. To reach your interplanetary goal in a star ship you will need to calculate travel time accounting for not only your speed but the speed and rotation of everything else in the universe.

The sun and the solar system appear to be moving at 200 kilometers per second, or at an average speed of 448,000 mph (720,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way. The speed of each of the planets through our solar system is:

Mercury 47.9 km/s	Venus 35.0 km/s	Earth 29.8 km/s	Mars 24.1 km/s
Jupiter 13.1 km/s	Saturn 9.7 km/s	Uranus 6.8 km/s	Neptune 5.4 km/s
Pluto: 4.74 km/s

For Earth, this works out to about 67 thousand miles per hour while rotating on its axis at approximately 1,000 miles per hour. (460 meters per second at the equator)

A spacecraft leaving the surface of Earth needs to be going about 11 kilometers (7 miles) per second, or over 40,000 kilometers per hour (25,000 miles per hour), to reach escape velocity. Achieving escape velocity is one of the biggest challenges currently facing space travel.

The current human speed record is shared equally by the trio of astronauts who flew Nasa’s Apollo 10 mission. On their way back from a lap around the Moon in 1969, the astronauts’ capsule hit a peak of 24,790mph (39,897km/h) relative to planet Earth.

Generally, a conventional rocket has to be going about 17,000 mph for it to achieve orbit; otherwise known as LEO -- Low Earth Orbit. This is the minimum speed for a space going rocket. The farther from the Earth, the faster it needs to go. We list some other velocities for comparison.

Flight Plan	Speed required
Earth to LEO (low Earth orbit)	17,000 mph
Earth to Earth escape	24,200 mph
Earth to lunar orbit	25,700 mph
Earth to GEO (geosynchronous Earth orbit)	26,400 mph
Earth to solar escape	36,500 mph

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