
one more reason the speed is faster is not the ship speed, but the distance is half, or the same as round trip for a one way trip.
Both at near top speed that is.
The one with the less distance would reach less velocity due to inertia.
Edit started 4 hours later:
speed of mars
86,871 kilometers per hour
Mars revolves or orbits around the Sun once every 1.88 Earth years, or once every 686.93 Earth days. Mars travels at an average speed of 53,979 miles per hour or 86,871 kilometers per hour in its orbit around the Sun.
speed of earth
Thus, the surface of the earth at the equator moves at a speed of 460 meters per second–or roughly 1,000 miles per hour. As schoolchildren, we learn that the earth is moving about our sun in a very nearly circular orbit. It covers this route at a speed of nearly 30 kilometers per second, or 67,000 miles per hour.
speed of venus
78,341 miles per hour
Venus revolves or orbits around the Sun once every 0.615 Earth years, or once every 224.7 Earth days. Venus travels at an average speed of 78,341 miles per hour or 126,077 kilometers per hour in its orbit around the Sun.
top speed of fastest voyager
The record for fastest launch velocity belongs to the New Horizons probe, which lifted off in 2006 on a mission to Pluto and the Kuiper Belt. This 1,054-lb. (478 kilograms), piano-size spacecraft sped away from the Earth at a blistering pace of 36,000 mph (almost 58,000 km/h). Jul 6, 2016
fastest craft in space
After a five-year jaunt through space, NASA’s robotic Juno spacecraft arrived at Jupiter on July 4, 2016, and the gas giant’s impressive gravity accelerated the probe to approximately 165,000 mph (265,000 km/h) relative to Earth. This made Juno the fastest-moving human-made object in history. Jul 6, 2016
And though Juno is currently the fastest human-made object, it remains to be seen how long the space probe can hold onto the impressive title. Solar Probe Plus, a NASA mission scheduled to launch in 2018, is designed to fly into the sun’s atmosphere, making it the first probe to do so. Due to the enormity of Earth’s nearest star, the probe is expected to reach orbital velocities as high as 450,000 mph (724,000 km/h). For perspective, at this speed, you could travel from the Earth to the moon in about 30 minutes.
speed of voyager 1
On February 17, 1998, Voyager 1 reached a distance of 69 AU from the Sun and overtook Pioneer 10 as the most distant spacecraft from Earth. Travelling at about 17 kilometers per second (11 mi/s) it has the fastest heliocentric recession speed of any spacecraft.
62,140 km/h
speed of voyager 2
Voyager 2/Max speed
57,890 km/h
End of Edit 5 hours after original, 1 hour after the beginning of Edit.