Life on MarsThe possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no proof of past or present life has been found on Mars. Cumulative evidence suggests that during the ancient Noachian time period, the surface environment of Mars had liquid water and may have been habitable for microorganisms, but habitable conditions do not necessarily indicate life.
OrbitIn celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory.
Planetary habitabilityPlanetary habitability is the measure of a planet's or a natural satellite's potential to develop and maintain environments hospitable to life. Life may be generated directly on a planet or satellite endogenously or be transferred to it from another body, through a hypothetical process known as panspermia. Environments do not need to contain life to be considered habitable nor are accepted habitable zones (HZ) the only areas in which life might arise.
BiosignatureA biosignature (sometimes called chemical fossil or molecular fossil) is any substance – such as an element, isotope, or molecule – or phenomenon that provides scientific evidence of past or present life. Measurable attributes of life include its complex physical or chemical structures and its use of free energy and the production of biomass and wastes. A biosignature can provide evidence for living organisms outside the Earth and can be directly or indirectly detected by searching for their unique byproducts.
Climate of MarsThe climate of Mars has been a topic of scientific curiosity for centuries, in part because it is the only terrestrial planet whose surface can be directly observed in detail from the Earth with help from a telescope. Although Mars is smaller than the Earth, 11% of Earth's mass, and 50% farther from the Sun than the Earth, its climate has important similarities, such as the presence of polar ice caps, seasonal changes and observable weather patterns. It has attracted sustained study from planetologists and climatologists.
Mars Reconnaissance OrbiterThe Mars Reconnaissance Orbiter (MRO) is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on August 12, 2005, at 11:43 UTC and reached Mars on March 10, 2006, at 21:24 UTC. In November 2006, after six months of aerobraking, it entered its final science orbit and began its primary science phase.
Terraforming of MarsThe terraforming of Mars or the terraformation of Mars is a hypothetical procedure that would consist of a planetary engineering project or concurrent projects, with the goal to transform Mars from a planet hostile to terrestrial life to one that can sustainably host humans and other lifeforms free of protection or mediation. The process would involve the modification of the planet's extant climate, atmosphere, and surface through a variety of resource-intensive initiatives, and the installation of a novel ecological system or systems.
NadirThe nadir (ˈneɪdɪər,_-dər, alsoUKˈnædɪər; naðʕīr) is the direction pointing directly below a particular location; that is, it is one of two vertical directions at a specified location, orthogonal to a horizontal flat surface. The direction opposite of the nadir is the zenith. Since the concept of being below is itself somewhat vague, scientists define the nadir in more rigorous terms. Specifically, in astronomy, geophysics and related sciences (e.g.
Mariner programThe Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the inner Solar System - visiting the planets Venus, Mars and Mercury for the first time, and returning to Venus and Mars for additional close observations. The program included a number of interplanetary firsts, including the first planetary flyby, the planetary orbiter, and the first gravity assist maneuver.
Discovery ProgramThe Discovery Program is a series of Solar System exploration missions funded by the U.S. National Aeronautics and Space Administration (NASA) through its Planetary Missions Program Office. The cost of each mission is capped at a lower level than missions from NASA's New Frontiers or Flagship Programs. As a result, Discovery missions tend to be more focused on a specific scientific goal rather than serving a general purpose. The Discovery Program was founded in 1990 to implement the policy of the then-NASA administrator Daniel S.
