Have you ever wondered how long it might take to travel to Mercury?
At its closest point, Mercury gets to within 77.3 million km away from
the Earth. Let’s see how long it takes for various spacecraft to get to
Mercury.
For starters, let’s look at how long light itself takes to make the
journey. Light takes only 4.3 minutes to travel from the Earth to
Mercury when they’re at their closest point.
The fastest spacecraft ever launched from Earth is NASA’s New
Horizons mission, currently on its way to visit Pluto and the outer
Solar System. New Horizons is traveling at about 80,000 kilometers per
hour. It would take about 40 days to get from the Earth to Mercury when
they’re closest.
Of course, spacecraft don’t travel a straight route between planets,
they follow a path that uses the least amount of energy, and so it takes
them longer… a lot longer. The first spacecraft to actually make the
journey to Mercury was NASA’s Mariner 10, which launched on November 3,
1973. It made its first Mercury flyby on March 29, 1974. Mariner 10 took
147 days to get from Earth to Mercury.
