Solar System


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*These are satellite photos sourced from NASA's Flickr Commons and are used for educational and informational purposes.


  • The discovery of Mars can be traced back to ancient civilizations. However, the first recorded observations of Mars were made by ancient astronomers. The ancient Egyptians, Greeks, and Chinese all observed the red planet in the night sky.

  • One of the earliest known records of Mars observations dates back to ancient Egypt around 1534 BCE. Egyptian astronomers kept detailed records of the motion of the planets, including Mars.

  • The Greeks also made significant contributions to the understanding of Mars. Around the 4th century BCE, the Greek philosopher Aristotle observed and documented the characteristics and movements of Mars.

The most significant advancements in understanding Mars came with the invention of the telescope. In the 17th century, Italian astronomer Galileo Galilei made telescopic observations of Mars, noting its disc-like appearance and phases similar to those of the Moon. However, his telescope was not powerful enough to provide detailed information about the planet's surface features.

It was not until the late 19th and early 20th centuries that more detailed observations of Mars were made. In 1877 the Italian astronomer Giovanni Schiaparelli made observations of Mars using a powerful telescope and described what he called "canali" (meaning channels or canals). These observations sparked a great deal of controversy and speculation about the possibility of intelligent life on Mars.

The American astronomer Percival Lowell continued the study of Mars.He constructed an observatory in Flagstaff, Arizona, specifically dedicated to observing Mars. Lowell made detailed drawings of the Martian surface, suggesting the existence of a complex network of canals and a dying civilization. However, it was later discovered that Lowell's observations were influenced by visual illusions and not an accurate representation of the Martian surface.


  • The first successful mission to Mars was the Mariner 4 flyby conducted by NASA in 1965. It provided the first close-up images of the planet's surface, revealing a barren and cratered landscape.

  • Several subsequent missions, such as Mariner 9, Viking 1, and Viking 2, were launched in the 1970s and played crucial roles in studying the planet's atmosphere, geology, and weather patterns.

  • One of the most significant advancements in Mars exploration came with the deployment of rovers. The Sojourner rover, part of NASA's Mars Pathfinder mission in 1997, was the first successful Mars rover, providing valuable data about the planet's geology.

  • Later, the Mars Exploration Rover (MER) mission launched two rovers: Spirit and Opportunity (2003). These rovers extensively explored Mars' surface, studying rocks, soil, and the history of water on the planet.

Current Rover Missions
NASA's Mars Science Laboratory mission, launched in 2011, deployed the Curiosity rover, which is still operational. Curiosity is equipped with advanced instruments and has made groundbreaking discoveries, such as evidence of ancient water and organic molecules. Additionally, China's Tianwen-1 mission, launched in 2020, included an orbiter, a lander, and a rover, named Zhurong. The Zhurong rover became China's first successful Mars rover mission, further expanding our knowledge of the planet.

Sample Return Missions
Sample return missions aim to collect Martian rock and soil samples and return them to Earth for detailed analysis. NASA's Mars 2020 mission, which included the Perseverance rover, successfully landed on Mars in February 2021. Perseverance is equipped with advanced instruments, including the Mars Sample Caching System, designed to collect samples for future return to Earth. The mission also deployed the Ingenuity helicopter, which demonstrated powered flight on another planet.

International Collaboration
Mars exploration is not limited to NASA alone. The European Space Agency (ESA) has also been involved in Mars missions, including the Mars Express orbiter (launched in 2003) and the ExoMars mission (launched in 2016). ExoMars consists of an orbiter and a rover (expected to be launched in 2022) and aims to search for signs of past or present life on Mars.

Future Missions
Several upcoming missions are planned for Mars exploration. NASA's Mars Sample Return campaign, in collaboration with ESA, aims to retrieve the samples collected by Perseverance and return them to Earth. Additionally, NASA's Mars Sample Return Lander mission is being developed to deliver a future lander to collect the cached samples.


  • When astronomers and astronauts think about potentially habitable planets, the first one that springs to mind is Mars.

  • Mars is on average much colder (as low as -225 degrees) and has a significantly lower gravity (38%) than Earth, it has a similar tilt and spin, which means it has a similar day and seasons, unlike many of the other planets that inhabit our solar system

It is also the only other planet in our solar system that ever seemed to have the possibility of supporting life of its own. It has two moons, Phobos and Deimos, an atmosphere composed mainly of carbon dioxide, and owes its distinctive red color to the iron oxide, or rust, on its surface. It has both the largest volcano, Olympus Mons, and one of the largest canyons, Valles Marineris, in the solar system!

Last updated February 23, 2023. Content written by Trevor Macduff.