Mars is one of the Earth's closest neighbors in the Solar System. Even though it isn't known who discovered it, people have known about its existence since 1610. A professor in South Africa described the celestial body as a previously undiscovered star and ended up being printed in a news service.
It is safe to say that he wasn't the first to discover the Red Planet.
Mars Rediscovered
Peter Dunsby is a cosmology professor at the University of Cape Town. He submitted a discovery to the Astronomer's Telegram. It is a service that features news about the latest in astronomy. Dunsby's report of what he observed in the night sky showed that he had been tracking Mars since he first observed it on March 8.
His report of the discovery of Mars makes no mention that he had found a new planet. Instead, Dunsby records where he had seen Mars at this point. He notes in the Digital Sky Survey plates that there is no celestial body described at this location.
Dunsby describes Mars as the brightest star in its location. He notes that this discovery will require further observations. What further observation discovered was that Dunsby was referring to Mars in his report.
Astronomer's Telegram was forced to write a correction about the subject. It later congratulated Dunsby for his discovery of the planet Mars in a tongue-in-cheek tweet. Dunsby showed that he could take a joke by saying that he learned his lesson, that he will need to check twice next time.
Actual 'Discovery' Of Mars
It is not known when Mars was observed in the sky, but it is known when it was first considered a planet. Nicolaus Copernicus was the first person to suggest that Mars might be a planet just like Earth. Some of the earliest observations of Mars were made by Danish astronomer Tycho Brahe. He was able to calculate the position of the planet in 1576.
The first person to observe Mars through a telescope, although it was a primitive one, was Galileo Galilei in 1609. In 1659, astronomer Christiaan Huygens was able to see Mars by using a more advanced telescope.
Mars was observed as far back as 400 BC by the Babylonians. They knew the planet as Nergal. Ancient Egyptians observed that the stars were in fixed orbit around the Sun. Besides Mars, they also observed the planets Mercury, Venus, Jupiter, and Saturn in the night sky.