Mercury, Venus, Mars, Jupiter, and Saturn are visible from Earth with the naked eye. These planets have been observed throughout all of human history and have been the source of much fascination, worship and speculation. Except for the name of Earth, which is Germanic and Old English in origin, the planets names are derived from Roman and Greek mythology. Uranus, Neptune and Pluto were given mythological names to match the other planets. After 69 years of technological innovations, humankind has now captured images of all of our planetary neighbors. Here are the first images of the planets in our solar system.
9. Mercury, 1974
NASA launched the Mariner 10 space probe, which collected our first images of both Venus and Mercury, in November of 1973. Our first clear image of Mercury’s cratered moon-like surface was captured in March of 1974. With Mercury being so close to the Sun, thermal blankets and a sunshade needed to be installed on the probe. This mosaic of Mercury is composed from 18 images that were taken during a 13-minute period from a distance of 125,000 miles from the surface. It’s still a remarkable view.
8. Venus, 1974
By 1973, The USSR had already sent 18 probes to our sister planet, but 12 of those missions were failures. The successful missions, including NASA’s Mariner 2 in 1962, revealed that the planet had a surface temperature of approximately 900 degrees Fahrenheit and an atmospheric pressure 90 times greater than Earth’s. On February 5, 1974, NASA’s Mariner 10 mission took pictures of Venus for the first time. The photo made use of an ultraviolet filter and was color enhanced so that its atmosphere would appear as it would to the human eye.
7. Earth, 1946
Humanity got its first glimpse of Earth, as seen from space, shortly after the end of World War II. On October 24, 1946, long before the Sputnik satellite, a group of soldiers and scientists working in New Mexico captured this grainy image of Earth. A 35-millimeter motion picture camera, which took a picture every second and a half, was attached to a V-2 missile. After reaching an altitude of 65 miles, the rocket came racing back towards the Earth at 340 mph. The camera was smashed to bits but the film survived the journey. Apparently the scientists “went nuts” when they first saw the images.
6. Mars, 1965
On July 15, 1965, NASA’s Mariner IV mission captured our first close look at Mars. While the image of the red planet isn’t very well defined it was initially received with tremendous excitement. From a distance of 135 million miles from Earth, this image represented a new record for long-distance communication and paved the way for future missions. This dot-matrix image is composed of 40,000 dots and each dot was digitally captured in 6-bit binary code. It took roughly nine hours for the code to be transmitted back to Earth. This was a remarkable accomplishment five decades ago.
5. Jupiter, 1973
After travelling for more than a year, and navigating through the asteroid belt, on Dec. 4, 1973, NASA’s Pioneer 10 spacecraft sent back its first images of Jupiter. The photo shows Jupiter growing in size as the probe approached the gas giant. This mission paved the way for the more ambition Voyager program. Pioneer 10 sent its last signal back to Earth in 2003 from 7.5 billion miles away. The Pioneer 10 is the first man-made object to achieve escape velocity from our solar.
4. Saturn, 1979
The Pioneer 11 spacecraft launched from Cape Canaveral on April 5, 1973. On September 1, 1979, the Pioneer 11 made its first pass by Saturn. NASA decided to send the Pioneer through Saturn’s outer rings and test the safety of the route. A successful pass through the ring system meant that the Voyager spacecraft’s would be able to use the route the following year. If the Pioneer 11 hadn’t survived the route, the Voyager spacecrafts would have had to keep their distance from Saturn and would not have been able to successfully visit Uranus and Neptune. The Pioneer 11 captured this image from over 1.7 million miles away from Saturn.
3. Uranus, 1986
The Voyager 2 spacecraft was launched on August 20, 1977. It passed by Jupiter in July 1979, Saturn in August 1981 and then reached Uranus in January of 1986. Voyager 2 captured thousands of images of the planet and its moons. It discovered two new rings and ten previously unseen moons. The probe calculated that a day on Uranus is just over 17 hours and that its temperature is the same at the equator as it is at the poles. Voyager 2 remains the only spacecraft to have visited Uranus.
2. Neptune, 1989
After a gravity assist around Uranus, NASA’s Voyager 2 became the first spacecraft to visit Neptune in 1989. The spacecraft took 12 years to reach its final target. This image was taken from roughly 4.5 million miles away and about five days before the Voyager 2 made its closest pass by the planet. It then passed by Neptune’s north pole at a mere 3000-mile distance and then came within 25,000 miles of Neptune’s largest moon, Triton. The Voyager 2 is currently around 10 billion miles away from Earth and travelling through the outermost layer of our solar system known as the Heliosheath. It will eventually join the Voyager 1 in interstellar space.
1. Pluto, 2015
Pluto was still classified as a planet when the New Horizon spacecraft was launched. We’re going give the little a guy a break and include it in this list. On January 19, 2006, New Horizons was launched from Cape Canaveral and set the record for the highest launch speed of a human-made object from Earth. In February of 2007, the probe swung by Jupiter and set its course for Pluto. New Horizons was brought back online on December 6, 2014, after spending most of its journey in hibernation. After travelling more than 3 billion miles, the spacecraft, travelling at 36,000 mph, raced by Pluto from a distance of only 7,800 miles above the surface. Many of us held our breath as we waited for our first detailed glimpse of this lonely dwarf planet. This image was taken 476,000 miles from Pluto.
