In December of 1962 Mariner 2 became the first robotic spacecraft to conduct a successful encounter with another planet. It was one of the first attempts by mankind to explore planets in the Solar System, and it started with Venus. Mariner 2 carried two radiometers , a micrometeorite sensor, a solar plasma sensor, a charged particle sensor, and a magnetometer. It was on a mission to make basic measurements Venus’ atmosphere. Mariner 2 did not have a camera on board, so it did not send back any images during its Venus flyby. It was 12 years after the Mariner 2 flyby that Mariner 10 snapped this picture of Venus
Mariner 10 also conducted three flyby missions of Mercury where it took a wealth of images of the Sun’s closest neighbor. But our first glimpse of Mars came from the Mariner 4 in 1964. Mariner 4 was designed to conduct closeup scientific observations of Mars and it was the first spacecraft to return images from deep space.
For the last 50 years we have conducted flybys of every planet in the Solar system and many of their moons. Data has been gathered to confirm or enhance our knowledge of or friends in heliocentric orbits and majestic images of far away worlds have been beamed back. These discoveries and explorations always inspire a sense of awe in us and remind us of how small we are living on the pale blue dot.
Yesterday, July 14 2015, at 11:49 UTC (07:49 EDT), the New Horizons mission from NASA flew 12,600 km (7,800 mi) above the surface of dwarf planet Pluto in the Kuiper belt. Along the way New Horizons took images of Pluto and recorded scientific data regarding Methane. From the images we can see ice mountains towering as high as 11,000 ft (3,500 meters) on the surface of the dwarf planet.
The discoveries made of Mariner 2 included items such as the slow rotation rate for Venus, surface temperatures and pressures, atmosphere, and the lack of a magnetic field. With the advancements made in space instrumentation I am sure the wealth of data gathered by the onboard sensors of New Horizons will lead to magnificent scientific discoveries, and further enhance our understanding of our far away neighbor. Also as important, it will instill our need to push the boundaries of science to continue exploring space for all the majestic things it has to offer.