Mercury was discovered in 1631 Pierre Gassendi when he first observed Mercury moving across the sun. A few years later another astronomer discovered phases, meaning that the planet orbited the sun. Venus was the second planet discovered because of its brightness and has been referenced in many cultures. The most well known records of Venus come from the Romans, who were responsible for its name and based it off of the goddess of beauty. While there are no records of the first person to observe the planet Galileo Galilei found that the planet did orbit the sun after observing its phases.
Earth: Though we can’t observe the planet we live on unless we’re in a spaceship Copernicus presented a Heliocentric view of our solar system in 1514. In 1543 he published a book on the revolutions that conflicted with the beliefs of other astronomers in the field but brought an equal amount of support for the ideas it proposed.
Mars: Mars is the fourth planet in the solar system and was named after the Roman god of war. Giovanni Schiaparelli viewed the planet through a telescope in 1877 and used the word Canali to describe the planet and what he saw on it. This was misinterpreted as canals, leading to the popular belief that Mars once supported life and was habitable. This idea was furthered by Camille Flammarion who also stated the so called canals were artificial.
Jupiter: Jupiter is the largest planet in the solar system. The planet was named after the king of the Roman
Jupiter: The largest planet in our solar system, Jupiter has long been watched since ancient times. It helped guide the Chinese 12 year cycle, and the planet was named for the king of the Roman gods. It also provided a big target for early astronomers. Galileo was the first to observe Jupiter’s four major moons, now known as the Galilean Moons: Io, Europa, Ganymede and Callisto, named for Zeus’s lovers. Astronomer Robert Hooke first discovered a major storm system on the gas planet, and it was confirmed by Giovanni Cassini in 1665, believed to be the first sightings of Jupiter’s Great Red Spot, which was later formally recorded in 1831.
Saturn: the Romans named the planet for their God of Agriculture. However, it wasn’t until Galileo turned his attention to the planet in 1610 before the planet’s dominant feature was uncovered then. While he studied the planet’s features, he believed he’d uncovered several orbiting moons. However, it wasn’t until 1655, when Christiaan Huygens, with a more powerful telescope, discovered that the feature was actually a ring that encircled the entire planet. Shortly thereafter, he uncovered the Saturn’s first moon, Titan. During his own observations, Giovanni Cassini, in 1671, uncovered four additional moons: Iapetus, Rhea, Tethys and Dione and a gap in the planet’s rings, leading him to believe that the rings were made up of smaller particles.
Uranus: The seventh planet, Uranus, is hard to detect without the aid of a telescope, and thus, the planet doesn’t have the same long history as its other neighbors. Watching the skies in December 1690, astronomer John Flamsteed first noted the planet, but identified it as a star, which he named 34 Tauri. It wasn’t until March 13th, 1781 that Herschel first believed that the star that he was studying was a comet. It wasn’t until he began to study the object’s orbit when he found that it was nearly circular, leading him to believe that it was in fact a planet. Gizmodo.com
Neptune: The last ‘official’ planet in our solar system is Neptune. Orbiting 30 AU from the Sun, it’s the first planet to have been discovered through mathematics, rather than direct observation. Astronomers studying Uranus found that the planet was deviating from their predictions, and attempted to uncover the problem. The planet’s orbit was already known to have been influenced by the other major bodies in the Solar System, but even with the calculations at hand, Uranus was defying expectations. In 1835, Halley’s Comet reached its perihelion slightly later than predicted, leading astronomers to believe that there was an additional body in the system that was influencing Uranus.
Astronomers began to look further out for something that would explain the planet’s movements. Astronomers in both England and France began to crunch the numbers: John Couch Adams and Urbain Le Verrier. Between 1843 and 1845, Adams worked out the calculations, but was rebuffed by the Royal Astronomical Society. Le Verrier found a similar reception, and turned to Johann Gottfried Galle, who, following Le Verrier’s instructions, discovered the new planet exactly where it was predicted to be on September 23rd, 1846. The next month, an English astronomer discovered Neptune’s moon Triton. The solar system instantly doubled in size with the discovery. Gizmodo.com
The sun: The Greek philosopher Anaxagoras first proposed that the Sun was a burning ball of fire, larger than a Greek Island, and not the chariot of a god. And other astronomers were able to calculate the distance to the Sun with surprising accuracy. In the modern scientific era Lord Kelvin proposed that the Sun was ball of hot liquid that was slowly cooling. But it wasn’t until the early 20th century that scientists were finally able to figure out what the source of the Sun’s energy is. universetoday.com
Planets with a moon:
Earth: the moon: Earth’s only natural satellite is simply called ‘the Moon’ because people didn’t know other moons existed until Galileo Galilei discovered four moons orbiting Jupiter in 1610. solarsystem.nasa.gov
Mars: Phobos and Deimos: The two moons of Mars are Phobos and Deimos. They are irregular in shape. Both were discovered by Asaph Hall in August 1877 and are named after the Greek mythological twin characters Phobos (panic/fear) and Deimos (terror/dread) who accompanied their father Ares into battle. wikipedia
Jupiter: the galilean moons: The Galilean moons (or Galilean satellites) are the four largest moons of Jupiter—Io, Europa, Ganymede, and Callisto. They were first seen by Galileo Galilei in December 1609 or January 1610, and recognized by him as satellites of Jupiter in March 1610. wikipedia
Saturn: Mimas: Mimas was discovered on Sept. 17, 1789 by English astronomer William Herschel, using his 40-foot reflector telescope. Ground-based astronomers could only see Mimas as little more than a dot until Voyagers I and II imaged it in 1980. The Cassini spacecraft made several close approaches and provided detailed images of Mimas. solarsystem.nasa.gov
Uranus: Umbriel: Umbriel, along with its fellow moon Ariel, was discovered by English astronomer William Lassell on October 24th, 1851.
Neptune: Triton: Triton is the largest of Neptune’s moons. Discovered in 1846 by British astronomer William Lassell — just weeks after Neptune itself was found — the moon showed some strange characteristics as astronomers learned more about it.
Kuiper Belt: The first of these strange bodies, which astronomers call Kuiper Belt Objects (KBOs), came to light in 1992, discovered by Dave Jewitt and Jane Luu — a pair of scientists who didn’t believe the outer solar system was empty. Beginning in 1987 they had doggedly scanned the heavens in search of dim objects beyond Neptune. It took five years, looking off-and-on through the University of Hawaii’s 2.2 m telescope, but they finally found what they were after: a reddish-colored speck 44 AU from the Sun — even more distant than Pluto! Jewitt (University of Hawaii) and Luu (UC Berkeley) wanted to name their find ‘Smiley,’ but it has since been cataloged as ‘1992 QB1.’ That discovery marked our first glimpse of the long-sought Kuiper Belt, named after Gerard Kuiper who, in 1951, proposed that a belt of icy bodies might lay beyond Neptune.
Pluto: Discovered in 1930, Pluto was long considered our solar system’s ninth planet. But after the discovery of similar intriguing worlds deeper in the distant Kuiper Belt, icy Pluto was reclassified as a dwarf planet. Pluto is orbited by five known moons, the largest of which is Charon. Charon is about half the size of Pluto itself, making it the largest satellite relative to the planet it orbits in our solar system. Pluto and Charon are often referred to as a ‘double planet.’
Ceres: Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter and the only dwarf planet located in the inner solar system. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801. And when Dawn arrived in 2015, Ceres became the first dwarf planet to receive a visit from a spacecraft. Called an asteroid for many years, Ceres is so much bigger and so different from its rocky neighbors that scientists classified it as a dwarf planet in 2006. Even though Ceres comprises 25 percent of the asteroid belt’s total mass, tiny Pluto is still 14 times more massive. Ceres is named for the Roman goddess of corn and harvests. The word cereal comes from the same name.