The 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.
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined,and slightly less than one one-thousandth the mass of the Sun. Jupiter orbits the Sun at a distance of 5.20 AU (778.5 Gm) with an orbital period of 11.86 years. Jupiter is the third brightest natural object in the Earth's night sky after the Moon and Venus,and it has been observed since prehistoric times. It was named after Jupiter,the chief deity of ancient Roman religion.
A biosignature is any substance –such as an element,isotope,molecule,or phenomenon –that provides scientific evidence of past or present life on a planet. Measurable attributes of life include its complex physical or chemical structures,its use of free energy,and the production of biomass and wastes.
The New Frontiers program is a series of space exploration missions being conducted by NASA with the purpose of furthering the understanding of the Solar System. The program selects medium-class missions which can provide high science returns.
The atmosphere of Mars is the layer of gases surrounding Mars. It is primarily composed of carbon dioxide (95%),molecular nitrogen (2.85%),and argon (2%). It also contains trace levels of water vapor,oxygen,carbon monoxide,hydrogen,and noble gases. The atmosphere of Mars is much thinner than Earth's. The average surface pressure is only about 610 pascals (0.088 psi) which is less than 1% of the Earth's value.
The Lunar and Planetary Laboratory (LPL) is a research center for planetary science located in Tucson,Arizona. It is also a graduate school,constituting the Department of Planetary Sciences at the University of Arizona. LPL is one of the world's largest programs dedicated exclusively to planetary science in a university setting. The Lunar and Planetary Lab collection is held at the University of Arizona Special Collections Library.
The Mars general circulation model (MGCM) is the result of a research project by NASA to understand the nature of the general circulation of the atmosphere of Mars,how that circulation is driven and how it affects the climate of Mars in the long term.
The exploration of Uranus has,to date,been through telescopes and a lone probe by NASA's Voyager 2 spacecraft,which made its closest approach to Uranus on January 24,1986. Voyager 2 discovered 10 moons,studied the planet's cold atmosphere,and examined its ring system,discovering two new rings. It also imaged Uranus' five large moons,revealing that their surfaces are covered with impact craters and canyons.
The study of extraterrestrial atmospheres is an active field of research,both as an aspect of astronomy and to gain insight into Earth's atmosphere. In addition to Earth,many of the other astronomical objects in the Solar System have atmospheres. These include all the gas giants,as well as Mars,Venus and Titan. Several moons and other bodies also have atmospheres,as do comets and the Sun. There is evidence that extrasolar planets can have an atmosphere. Comparisons of these atmospheres to one another and to Earth's atmosphere broaden our basic understanding of atmospheric processes such as the greenhouse effect,aerosol and cloud physics,and atmospheric chemistry and dynamics.
Jonathan I. Lunine is an American planetary scientist and physicist. Lunine teaches at Cornell University,where he is the David C. Duncan Professor in the Physical Sciences and chair of the Department of Astronomy. Having published more than 380 research papers,Lunine is at the forefront of research into planet formation,evolution,and habitability. His work includes analysis of brown dwarfs,gas giants,and planetary satellites. Within the Solar System,bodies with potential organic chemistry and prebiotic conditions,particularly Saturn's moon Titan,have been the focus of Lunine's research.
The atmosphere of Titan is the dense layer of gases surrounding Titan,the largest moon of Saturn. It is the only thick atmosphere of a natural satellite in the Solar System. Titan's lower atmosphere is primarily composed of nitrogen (94.2%),methane (5.65%),and hydrogen (0.099%). There are trace amounts of other hydrocarbons,such as ethane,diacetylene,methylacetylene,acetylene,propane,PAHs and of other gases,such as cyanoacetylene,hydrogen cyanide,carbon dioxide,carbon monoxide,cyanogen,acetonitrile,argon and helium. The isotopic study of nitrogen isotopes ratio also suggests acetonitrile may be present in quantities exceeding hydrogen cyanide and cyanoacetylene. The surface pressure is about 50% higher than on Earth at 1.5 bars which is near the triple point of methane and allows there to be gaseous methane in the atmosphere and liquid methane on the surface. The orange color as seen from space is produced by other more complex chemicals in small quantities,possibly tholins,tar-like organic precipitates.
MAVEN is a NASA spacecraft orbiting Mars to study the loss of that planet's atmospheric gases to space,providing insight into the history of the planet's climate and water. The name is an acronym for "Mars Atmosphere and Volatile Evolution" while the word maven also denotes "a person who has special knowledge or experience;an expert". MAVEN was launched on an Atlas V rocket from Cape Canaveral Air Force Station,Florida,on 18 November 2013 UTC and went into orbit around Mars on 22 September 2014 UTC. The mission is the first by NASA to study the Mars atmosphere. The probe is analyzing the planet's upper atmosphere and ionosphere to examine how and at what rate the solar wind is stripping away volatile compounds.
A planetary surface is where the solid or liquid material of certain types of astronomical objects contacts the atmosphere or outer space. Planetary surfaces are found on solid objects of planetary mass,including terrestrial planets,dwarf planets,natural satellites,planetesimals and many other small Solar System bodies (SSSBs). The study of planetary surfaces is a field of planetary geology known as surface geology,but also a focus on a number of fields including planetary cartography,topography,geomorphology,atmospheric sciences,and astronomy. Land is the term given to non-liquid planetary surfaces. The term landing is used to describe the collision of an object with a planetary surface and is usually at a velocity in which the object can remain intact and remain attached.
DAVINCI is a planned mission for an orbiter and atmospheric probe to the planet Venus. Together with the separate VERITAS mission,which will also study Venus,it was selected by NASA on 2 June 2021 to be part of their Discovery Program. Its acronym is inspired by Leonardo da Vinci in honor of his scientific innovations,aerial sketches and constructions.
Chemical cycling describes systems of repeated circulation of chemicals between other compounds,states and materials,and back to their original state,that occurs in space,and on many objects in space including the Earth. Active chemical cycling is known to occur in stars,many planets and natural satellites.
SPRITE was a proposed Saturn atmospheric probe mission concept of the NASA. SPRITE is a design for an atmospheric entry probe that would travel to Saturn from Earth on its own cruise stage,then enter the atmosphere of Saturn,and descend taking measurements in situ.
Venus In situ Composition Investigations (VICI) is a concept lander mission to Venus in order to answer long-standing questions about its origins and evolution,and provide new insights needed to understand terrestrial planet formation,evolution,and habitability.
OCEANUS is a mission concept conceived in 2016 and presented in 2017 as a potential future contestant as a New Frontiers program mission to the planet Uranus. The concept was developed by the Astronautical engineering students of Purdue University during the 2017 NASA/JPL Planetary Science Summer School. OCEANUS is an orbiter,which would enable a detailed study of the structure of the planet's magnetosphere and interior structure that would not be possible with a flyby mission.
The reported presence of methane in the atmosphere of Mars is of interest to many geologists and astrobiologists,as methane may indicate the presence of microbial life on Mars,or a geochemical process such as volcanism or hydrothermal activity.
