Curiosity (rover) in the context of Mount Sharp

A transit of Mercury across the Sun takes place when the planet Mercury passes directly between the Sun and a superior planet. During a transit, Mercury appears as a tiny black dot moving across the Sun as the planet obscures a small portion of the solar disk. Because of orbital alignments, transits viewed from Earth occur in May or November. The last four such transits occurred on May 7, 2003; November 8, 2006; May 9, 2016; and November 11, 2019. The next will occur on November 13, 2032. A typical transit lasts several hours. Mercury transits are much more frequent than transits of Venus, with about 13 or 14 per century, primarily because Mercury is closer to the Sun and orbits it more rapidly.

On June 3, 2014, the Mars rover Curiosity observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth.

Space exploration is the physical investigation of outer space by uncrewed robotic space probes and through human spaceflight.

While the observation of objects in space, known as astronomy, predates reliable recorded history, it was the development of large and relatively efficient rockets during the mid-twentieth century that allowed physical space exploration to become a reality. Common rationales for exploring space include advancing scientific research, national prestige, uniting different nations, ensuring the future survival of humanity, and developing military and strategic advantages against other countries.

Robotics is the interdisciplinary study and practice of the design, construction, operation, and use of robots.

Within mechanical engineering, robotics is the design and construction of the physical structures of robots, while in computer science, robotics focuses on robotic automation algorithms. Other disciplines contributing to robotics include electrical, control, software, information, electronic, telecommunication, computer, mechatronic, and materials engineering.

Martian regolith or areolith is the fine blanket of unconsolidated, loose, heterogeneous superficial deposits covering the surface of Mars. The term Martian soil typically refers to the finer fraction of regolith. So far, no samples have been returned to Earth, the goal of a Mars sample-return mission, but the soil has been studied remotely with the use of Mars rovers and Mars orbiters. Its properties can differ significantly from those of terrestrial soil, including its toxicity due to the presence of perchlorates.

A Mars rover is a remote-controlled motor vehicle designed to travel on the surface of Mars. Rovers have several advantages over stationary landers: they examine more territory, they can be directed to interesting features, they can place themselves in sunny positions to weather winter months, and they can advance the knowledge of how to perform very remote robotic vehicle control. They serve a different purpose than orbital spacecraft like Mars Reconnaissance Orbiter. A more recent development is the Mars helicopter.

As of May 2021, there have been six successful robotically operated Mars rovers; the first five, managed by the American NASA Jet Propulsion Laboratory, were (by date of Mars landing): Sojourner (1997), Spirit (2004–2010), Opportunity (2004–2018), Curiosity (2012–present), and Perseverance (2021–present). The sixth, managed by the China National Space Administration, is Zhurong (2021–2022).

Mars 2020 is a NASA mission that includes the rover Perseverance, the now-grounded small robotic helicopter Ingenuity, and associated delivery systems, as part of the Mars Exploration Program. Mars 2020 was launched on an Atlas V rocket at 11:50:01 UTC on July 30, 2020, and landed in the Martian crater Jezero on February 18, 2021, with confirmation received at 20:55 UTC. On March 5, 2021, NASA named the landing site Octavia E. Butler Landing. As of 12 December 2025, Perseverance has been on Mars for 1711 sols (1758 total days; 4 years, 297 days). Ingenuity operated on Mars for 1042 sols (1071 total days; 2 years, 341 days) before sustaining serious damage to its rotor blades, possibly all four, causing NASA to retire the craft on January 25, 2024.

Perseverance is investigating an astrobiologically relevant ancient environment on Mars for its surface geological processes and history, and assessing its past habitability, the possibility of past life on Mars, and the potential for preservation of biosignatures within accessible geological materials. It will cache sample containers along its route for retrieval by a potential future Mars sample-return mission. The Mars 2020 mission was announced by NASA in December 2012 at the fall meeting of the American Geophysical Union in San Francisco. Perseverance's design is derived from the rover Curiosity, and it uses many components already fabricated and tested in addition to new scientific instruments and a core drill. The rover also employs nineteen cameras and two microphones, allowing for the audio recording of the Martian environment. On April 30, 2021, Perseverance became the first spacecraft to hear and record another spacecraft, the Ingenuity helicopter, on another planet.

2001 Mars Odyssey is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectrometers and a thermal imager to detect evidence of past or present water and ice, as well as study the planet's geology and radiation environment. The data Odyssey obtains is intended to help answer the question of whether life once existed on Mars and create a risk-assessment of the radiation that future astronauts on Mars might experience. It also acts as a relay for communications between the Curiosity rover, and previously the Mars Exploration Rovers and Phoenix lander, to Earth. The mission was named as a tribute to Arthur C. Clarke, evoking the name of his and Stanley Kubrick's 1968 film 2001: A Space Odyssey.

Odyssey was launched April 7, 2001, on a Delta II rocket from Cape Canaveral Air Force Station, and reached Mars orbit on October 24, 2001, at 02:30 UTC (October 23, 19:30 PDT, 22:30 EDT). As of March 2025, it is still collecting data, and is estimated to have enough propellant to function until the end of 2025. It currently holds the record for the longest-surviving continually active spacecraft in orbit around a planet other than Earth, ahead of the Pioneer Venus Orbiter (served 14 years) and the Mars Express (serving over 20 years), at 24 years, 1 month and 22 days. As of October 2019 it is in a polar orbit around Mars with a semi-major axis of about 3,800 km or 2,400 miles.

PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple–IBM–Motorola alliance, known as AIM. PowerPC, as an evolving instruction set, has been named Power ISA since 2006, while the old name lives on as a trademark for some implementations of Power Architecture–based processors.

Originally intended for personal computers, the architecture is well known for being used by Apple's desktop and laptop lines from 1994 until 2006, and in several videogame consoles including Microsoft's Xbox 360, Sony's PlayStation 3, and Nintendo's GameCube, Wii, and Wii U. PowerPC was also used for the Curiosity and Perseverance rovers on Mars and a variety of satellites. It has since become a niche architecture for personal computers, particularly with AmigaOS 4 implementations, but remains popular for embedded systems.

Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed Curiosity, a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigating Mars's habitability, studying its climate and geology, and collecting data for a human mission to Mars. The rover carries a variety of scientific instruments designed by an international team.