Geography of Mars

Lecture Notes for the Midterm

• History of Mars exploration

  • See Viewgraphs:
    • "Early robotic explorations"
    • "Later robotic explanations"
    • "Mars Exploration Rovers"
    • "European missions"
    • "2008 and later missions"
  • Sources of data on Mars available today
    • NASA Mariner 4 flyby (1965)
    • NASA Mariner 6 flyby (1969)
    • NASA Mariner 7 flyby (1969)
    • USSR Mars 3 orbiter/lander combination (launched May 1971, orbiter achieved orbit in December 1971; operated until August 1972, sending back 60 images (but only a handful have been released).
      • Zulfar phototelevision camera that recorded images on film reels and then scanned and transmitted them. It could scan and transmit at 225 x 220 pixels (thumbnails) and retransmit select ones at 1,880 x 1,760 pixels at 6,144 bits/second (as opposed to your 10 mb home Internet connection!). The Zufar camera had a 350 mm objective lens.
      • Vega phototelevision camera, similar to the Zulfar camera, but with a 52 mm objective.
    • NASA Mariner 9 orbiter (13 November 1971 - 27 October 1972)
    • USSR Mars 4 (launched in July 1973, failure during orbit insertion February 1974, but a few images were returned)
    • USSR Mars 5 orbiter (launched in July 1973, failure during orbit insertion February 1974), but Mars 5 sent back a few images
    • NASA Viking 1 orbiter (1976: Orbiter 1 lasted until 1980;
      • Visual Imaging System (VIS): twin high-resolution, slow-scan television framing cameras, with six bands in the visible light spectrum (including one panchromatic band), yielding an image of ~40 x 44 km, of 7 bits (128 values), and 1056 x 1182 pixels.
      • Infrared Thermal Mapper (IRTM): A multichannel radiometer, with four small telescopes, each having seven IR detectors. Measured temperatures in the atmosphere and areas on the surface. Could read temperature differences within 1° C throughout the range from -130° C to +57° C.
      • Orbiter Radio Science: Two-way S-band and X-band radio links between the earth and the orbiter generated orbiter navigation data, martian gravitational data, interplanetary plasmas, and information on the solar corona through Doppler shifts, time-of-flight measurements, and occulation studies. The UHF bands used for orbiter-lander communication also generated surface and horizon information.
      • Mars Atmospheric Water Detector (MAWD): Infrared grating spectrometer, measuring reflected IR from the surface through the atmosphere. Spectral intervals were those around water-vapor absorption lines at 1.4 microns. Provided data on the amount of water in the line of sight.
    • NASA Viking 1 Lander (landed in western Chryse Planitia, at ~23° N and ~48° W and ~2.69 km elevation and lasted until 1982)
      • Two 360-degree cylindrical scan cameras
      • Sampler arm, with a collector head, temperature sensor, and magnet
      • Meteorology boom, holding temperature, wind direction, and wind velocity
      • Seismometer, magnet and camera test targets, and magnifying mirror
      • Biology experiment package was held in a temperature-controlled compartment on the inside of the lander body
      • Gas chromatograph mass spectrometer
      • X-ray fluorescence spectrometer
      • A pressure sensor was under the lander body
    • NASA Viking 2 orbiter (1976: lasted until 1978)
      • Visual Imaging System (VIS): twin high-resolution, slow-scan television framing cameras, with six bands in the visible light spectrum (including one panchromatic band), yielding an image of ~40 x 44 km, of 7 bits (128 values), and 1056 x 1182 pixels.
      • Infrared Thermal Mapper (IRTM): A multichannel radiometer, with four small telescopes, each having seven IR detectors. Measured temperatures in the atmosphere and areas on the surface. Could read temperature differences within 1° C throughout the range from -130° C to +57° C.
      • Orbiter Radio Science: Two-way S-band and X-band radio links between the earth and the orbiter generated orbiter navigation data, martian gravitational data, interplanetary plasmas, and information on the solar corona through Doppler shifts, time-of-flight measurements, and occulation studies. The UHF bands used for orbiter-lander communication also generated surface and horizon information.
      • Mars Atmospheric Water Detector (MAWD): Infrared grating spectrometer, measuring reflected IR from the surface through the atmosphere. Spectral intervals were those around water-vapor absorption lines at 1.4 microns. Provided data on the amount of water in the line of sight.
    • NASA Viking Lander 2 (landed in Utopia Planitia, ~200 km west of Crater Mie, ~48°N and ~226°W, 4.23 km in elevation and lasted until 1980)
      • Two 360-degree cylindrical scan cameras
      • Sampler arm, with a collector head, temperature sensor, and magnet
      • Meteorology boom, holding temperature, wind direction, and wind velocity
      • Seismometer, magnet and camera test targets, and magnifying mirror
      • Biology experiment package was held in a temperature-controlled compartment on the inside of the lander body
      • Gas chromatograph mass spectrometer
      • X-ray fluorescence spectrometer
      • A pressure sensor was under the lander body
    • USSR Phobos 2 (launched on 12 July 1988, lost on 29 January 1989, but a few images were returned)
    • NASA Mars Pathfinder lander/NASA Sojourner rover (1997)
      • Atmospheric Structure Instrument/Meterology Package (ASI/MET): A set of temperature (one thin wire thermocouple for measuring temperature during descent and three for continuous post-landing measurement at 25, 50, and 100 cm above the surface), pressure (Tavis magnetic reluctance diaphragm sensor), and wind sensors (six hot wire elements around the top of the lander mast and three aluminum cone wind socks)
      • Alpha Proton X-Ray Spectrometer (APXS: Derived from Russian Vega and Phobos missions and identical to the APXS on the doomed Mars 96 mission. APXS is mounted on the Sojourner Rover body, with its sensor head on a deployment mechanism carried by the rover. The emission of alpha particles at a target creates a scatter of alpha particles from the atomic nuclei of chemicals on and in that target. Similarly, protons are also sent off by alpha particle interactions with the nuclei of certain elements with atomic numbers from 9-14 can be collected and characterized. Also, alpha particles excite atoms and they then emit X-rays, which can be characterized by signature emission patterns associated with each element.
      • Imager For Mars Pathfinder IMP: A stereo imaging system with selectable filters allowing multipspectral color detection.
    • NASA Mars Global Surveyor orbiter (1997-2006)
      • Mars Orbiter Camera (MOC) created daily wide-angle weather-focussed images of Mars, as well as narrow angle images. It could pick out surface features as small as 1.4 m.
      • Mars Orbiter Laser Altimeter (MOLA): Transmitted infrared laser impulses toward the martian surface at 10 Hz and received the reflected light. It measured the time-of-flight and inferred the distance between the MGS and the surface. With millions of these impulses recorded and processed, MOLA generated a digital elevation model of martian topography. This is often shown in hypsometric tinting, cartographically strongly suggestive of a previous oceanic era on Mars. "Persuasive cartography"?
      • Thermal Emission Spectrometer (TES): Measures the thermal infrared radiation emitted by the martian surface, revealing geological and atmospheric information. Has collected over 200,000,000 infrared spectra so far, and served as the basis for maps of atmospheric dust loading and temperature distributions.
      • Electron Reflectometer (MAGNETOMETER): Measures magnetism on Mars. The martian magnetic field collapsed long ago but there are remnant signs of magnetism on the surface. The MAGNETOMETER has mapped these local sources and allowed modelling of the martian interaction with the solar wind
      • Gravity Field Experiment (RADIO SCIENCE): Maps anomalies in the planet's gravitational field by measuring minute tugging effects registered by the spacecraft's high-gain antenna, its telecommunication system, and the onboard ultra-stable oscillator.
    • NASA Mars Odyssey orbiter (2001)
      • THEMIS Thermal Emission Imaging System: Two independent multispectral scanning systems, with five visible light bands (with 19 m pixels) and ten infrared bands (with 100 m pixels). THEMIS focusses on identifying water and ice.
      • GRS Gamma Ray Spectrometer: The sensor package is mounted at the end of a 6 m boom. It detects gamma rays emitted by the martian surface due to its exposure to the highly energetic cosmic ray radiation from stars (including the sun). These emissions, collected by the Gamma Sensor on GRS form signature energy distributions that identify the chemistry of the emitting surface. Neutrons are also produced by this exposure (indeed, it is their release that excites surface chemicals into emitting gamma rays), and these are collected by the HEND and Neutron Spectrometers on the GRS. GRS has been used to create maps of hydrogen abundance in the upper meter of the martian surface, and hydrogen abundance indicates water (H₂O).
      • MARIE Martian Radiation Environment Experiment: An energetic particle spectrometer that focusses on the radiation environment during the cruise to Mars and in the near-Mars space environment. This instrument is intended to characterize the space radiation hazard for astronauts en route to or on the surface of Mars.
    • NASA Mars Reconnaissance Orbiter (MRO) (2006-)
      • HiRISE (High Resolution Imaging Science Experiment): telescopic visible light camera with ~1 m resolution and near-infrared at ~30-60 cm pixels allowing resolution of objects ~1.2 - 2.4 m
      • CTX (Context Imager): coarser resolution camera of a larger area to provide a regional context for HiRISE close-ups (~30 km swaths at 6 m per pixel)
      • MARCI (Mars Color Imager): 5 visible light bands and 2 ultraviolet bands to observe martian climate and generate daily weather reports of dust storms and changes in ozone, dust, carbon dioxide, and the polar caps
      • CRISM (Compact Reconnaissance Imaging Spectrometers for Mars): visible and infrared spectrometers creating maps resolved at ~18 m, meant to identify spectral signatures associated with minerals that precipitate out of water
      • SHARAD (Shallow Subsurface Radar): 15-25 MHz frequency radar designed to penetrate the martian surface down to a depth as great as 1 km. It looks for changes in the electrical reflection characteristics of the radar return that might indicate water or ice. The horizontal resolution of this instrument is about 0.3 - 3 km and the vertical resolution is about 15 m in free space and 10 m underground.
      • MCS (Mars Climate Sounder): observes temperature, humidity, and dust by measuring changes in atmospheric temperature or composition with height in 9 different channels, 1 spanning the visible light and nearby wavelengths (0.3-3 microns) and 8 in the thermal infrared (12-50 microns). MCS looks at the martian horizon from orbit, creating a vertical layering of readings
    • NASA Mars Exploration Rovers (MER) Spirit and Opportunity (January 2004-)
      • Rovers
        • Spirit in Gusev Crater
        • Opportunity in Meridiani
      • Instruments
        • Panoramic Camera (Pancam: A stereoscopic pair of CCD cameras with 4,000 x 24,000 pixel resolution and a filter wheel that allows for 8 different wavelength bands per camera (11 in total for the pair) to be imaged separately, giving Pancam multispectral imaging capacity. The stereoscopic pairing affords parallax and depth perception. Pancam is used to scan the horizon to identify landforms of possible relevance to the search for evidence of water, to map the rovers' whereabouts, and to pick interesting soils and rocks for further investigation. It is also part of the navigation system, using filters to point at the sun to get an absolute bearing. The Pancam team has put a lot of its imagery online.
        • Microscopic Imager (MI): Mounted on the robotic arm of the rovers, the MI ombines a microscope with a CCD camera of 1024 x 1024 pixel resolution and broad-band spectral resolution in black and white.
        • Engineering Navigation Cameras (Navcam): A stereo pair of black and white visible light cameras that generate a 3D panoramic view of the areas around the rovers.
        • Four Engineering Hazard Avoidance Cameras (Hazcam): Mounted front and back along the lower portion of the rovers, the Hazcams are b/w visible light cameras mounted rigidly on the rovers to help spot obstacles or changes in elevation that could disrupt the rovers.
        • Miniature Thermal Emission Spectrometer (Mini-TES): An infrared spectrometer that helps identify minerals (such as the water-diagnostic carbonates) by their thermal emissivity spectral signatures. Through a clever mirroring system, the Mini-TES can view the same objects and features at the same time as the Pancam.
        • Mössbauer Spectrometer (MB): Dedicated to the spectroscopy of iron-bearing minerals. Its sensor head is mounted at the end of the robot arm, while its electronics are housed in the Warm Electronics Box on the body of the rover.
        • Alpha Particle X-Ray Spectrometer (APXS): This instrument has a small supply of radioactive alpha-particle emitters. An alpha-particle stream is directed at a target, which excites the molecules in the target. The alpha particles are reflected back into the instrument, along with X-rays that may have been emitted due to the excitation. The energy distribution signature of the returning alpha particles and the emitted X-rays allow characterization of the chemicals in the target object.
        • Rock Abrasion Tool (RAT): Allows martian rocks to be manipulated for further analysis. Over a two hour timeframe, it grinds holes about 45 mm in diameter and about 2 mm deep, exposing unaltered subsurface minerals for analysis. If these are different from the surface materials, the difference allows inference of the processes operating to alter the surface. The RAT was developed by Honeybee Robotics, which maintains a web site for the RAT's work.
        • Magnet Arrays: Three sets of magnets are housed on the RAT, the front of the rover (but reachable by the APXS and MB instruments), and the top of the rover deck within sight of the Pancam. They collect magnetized dust generated by the RAT, magnetized dust that just settles on the rovers, and even magnetized dust in motion carried by winds passing over the rovers.
    • ESA Mars Express orbiter (orbiter operating December 2003-)
      • ASPERA-3 Analyser of Space Plasmas and Energetic Atoms: Focusses on the solar wind's interactions with the martian atmosphere. The goal is to see how water vapor and other gasses escaped the martian system.
      • HRSC High/Super Resolution Stereo Colour Imager: A stereoscopic multispectral camera that can reach a 2 m resolution of surface features. The goal is a geological map showing the location of different minerals and rock types.
      • MaRS Radio Science Experiment: Uses the radio communication signals between the earth and the orbiter to do some "free" imaging of Mars' ionosphere, atmosphere, surface, and interior (through gravity effects).
      • MARSIS Subsurface Sounding Radar/Altimeter: A ground-penetrating radar instrument (1.3-5.5 MHz) that can reach as far as 5 km below the surface of Mars to look for radio echoes from subterranean water layers and also analyze the ionosphere of Mars.
      • OMEGA IR Mineralogical Mapping Spectrometer: Has two channels, 0.5-1.0 microns (visible light) and 1.0-5.2 (infrared), each of which is imaged by a telescope, a spectrometer, and an optical device. A major goal is identifying carbonates, which should be present if water is or was present on Mars.
      • PFS Planetary Fourier Spectrometer: Like OMEGA, PFS will collect spectra, but over a wider band of infrared wavelengths (1.2-45 microns) in order to focus on minerals in dust in the martian atmosphere. It will also infer temperature and pressure measurements for carbon dioxide by concentrating on the 15 micron carbon dioxide absorption band.
      • SPICAM UV and IR Atmospheric Spectrometer: Contains two sensors, one for UV light (118-320 nanometers), and the other for IR light (1-1.7 microns). The UV sensor will be used to collect stellar occultation readings of the atmosphere by being pointed at the horizon, limb readings by pointing at the horizon without a star in sight to get at Mars' atmospheric UV glow, and at the nadir to measure atmospheric absorbtion of UV and IR directly between the orbiter and the surface below. The IR sensor will be used only in nadir mode.
    • ESA Rosetta Mission to Comet 67 P/Churyumov- Gerasimenko
      • Rosetta did a successful gravitational-assist swing-by Mars
      • Carries OSIRIS package of Wide Angle Camera and Narrow Angle Camera (Optical, Spectroscopic, and Infrared Remote Imaging System)
      • Images in the ultraviolet through visible light to near-infrared (0.25 to 1.00 microns)
    • NASA Phoenix Lander is the first representative of a new class of NASA mission, the Scout class. These are to be small and cheap missions. Phoenix recycles the lander that was supposed to be sent as a component of the Mars Global Surveyor mission, but which had been cancelled from that mission for cost savings. Additionally, Phoenix carried new and improved copies of many of the instruments that were on the Mars Polar Lander/Deep Space 2 probes that crashed on arrival in 1999. Phoenix was launched on 4 August 2007 and landed in Vastitas Borealis around +68° and 234° E (north of Alba Mons) on 25 May 2008. It operated about two months longer than its three month design life, ultimately succumbing to the waning of sunlight below the levels needed to power operations on the 2nd of November. It was not designed to withstand winter conditions near the North Pole and was soon covered by dust from a storm and then in thick dry ice, which destroyed its solar panels. The instruments:
      • Mars Descent Imager (MARDI) was supposed to be a wide-angle color context imager and microphone that would record the final three minutes of descent. Unfortunately, there was the chance that the camera's data recording could have been too much for an interface card that might have been overwhelmed and dumped critical engineering data, so the decision was made to shut MARDI off to allow the other system uninterrupted access to the interface card.
      • Surface Stereo Imager (SSI) sat on a mast and provided high-resolution stereo panoramas of the area around the lander that could generate 3-d views. It was a multispectral scanner, using filters to record 12 bands in the optical and infrared areas. Spectra could then be used for geological and meteorological identifications.
      • Robotic Arm Camera (RAC) was attached to the Robotic Arm and its scoop. This allowed color imaging of the area around the lander, inspection of candidate soil and ice samples in trenches dug by the Robotic Arm, imaging of the walls and floors of trenches, and verification that scooped samples actually were in the scoop for analysis by other instruments.
      • Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) dissolved soil samples and tested for pH, magnesium,, sodium, chloride, bromide, sulfate, and dissolved oxygen and carbon dioxide. Soil grains were examined with the microscope to determine soil texture and composition. Needles pressed into soil gave feedback on ice content and how readily warmth and water vapor could penetrate it.
      • Thermal and Evolved Gas Analyzer (TEGA) combined eight tiny high temperature furnaces and a mass spectrometer. The soil and ice samples would be heated to 1000° C, which would cause them to vaporize (evolved gasses). Streams of these derived gasses would then go into the mass spectrometer for measurement of their mass and the concentrations within them of specific kinds of molecules and atoms. Its goal was to detect different isotopes of hydrogen (hydrogen and deuterium), oxygen, carbon, and nitrogen to figure out their sources.
      • Meteorological Station (MET) recorded daily temperatures and air pressures and dust and ice particle sizes, densities, and distributions.
      • Robotic Arm (RA) was a backhoe-like device with a jointed 2.35 m long arm that could dig down half a meter through the extremely hard soils of near-polar Mars to expose and collect ice and soil-ice mixes and deliver scoops of them to the MECA and TEGA
    • NASA Mars Science Laboratory/Curiosity Rover is luxuriously instrumented, the most capable and comprehensive rover or lander ever designed (well, until Perseverance came along). It is also far and away the biggest and heaviest one, too, so massive that the grape-cluster airbag approach would not work. NASA came up with an innovative, almost crazy landing process that entailed parachutes, separation of the heatshield and backshield, and firing four steerable engines on the descent stage carrying the rover to slow it down even more and stabilize it against any winds. Then, the descent stage or sky crane hovered and lowered the rover on cords to a soft landing, the lines were detached, and the sky crane then moved off to crash land nearby. Seven minutes of Rube Goldberg-esque terror!
      • MastCam, color imaging and videos, with one high-resolution camera system and a moderate resolution camera system similar to the Pancam on the MERs. Panchromatic color and has multiple filters to take monochrome images in particular bands. Can take high definition videos at 10 frames per second.
      • MAHLI or Mars Hand Lens Imager comparable to the hand lens used by geologists and physical geographers out in the field. Resolution as fine as 12.5 microns. Carries a white light source so it can image both night and day and an ultraviolet light source to induce fluorescence to aid in detection of carbonates and evaporites.
      • MARDI or Mars Descent Imager. Took 5 frame per second high resolution videos during descent to help in picking exploration paths after landing and give insight on the regional context of the landing site.
      • APXS or Alpha-ray Particle X-ray Spectrometer. The emission of alpha particles at a target creates a scatter of alpha particles from the atomic nuclei of chemicals on and in that target. Similarly, protons are also sent off by alpha particle interactions with the nuclei of certain elements with atomic numbers from 9-14 can be collected and characterized. Also, alpha particles excite atoms and they then emit X-rays, which can be characterized by signature emission patterns associated with each element.
      • ChemCam or laser-induced remote sensing of chemicals. This is the "death ray" you saw in the Curiosity animation: Its laser vaporizes materials in a very precise, 1 mm, area and analyzes the spectral return from the resulting plasma. It has a very high resolution camera (5-10 times as powerful as those on the MERs) for close-up work, but it can also work at a distance.
      • CheMin or Chemistry and Mineralogy instrument is a spectrometer that can identify minerals, such as olivine, pyroxene, hæmatite, gœthite, and magnetite, iron-rich minerals from the reactive branch of the Bowen Reaction Series and their alteration byproducts. This instrument can drill into rocks, withdraw a sample of powdered material, deposit it into a sample holder in the interior of the rover, and perform X-ray diffraction on it. This was shown in the Curiosity animation, too.
      • SAM or Sample Analysis at Mars is the large science laboratory payload on the Mars Science Laboratory. It consists of a mass spectrometer, gas chromatograph, and a tunable laser spectrometer. It is capable of analyzing distinct isotopes of carbon, hydrogen, and oxygen in such gasses as methane, water vapor, and carbon dioxide, which are essential to life (at least on Earth). This experimental package, then, will be used to assess whether Mars once supported some form of life (or still does).
      • RAD or Radiation Assessment Detector. It will be directed skyward to measure galactic cosmic rays and solar particles passing through the martian atmosphere, part of an assessment of the radiation environment that will face human visitors and colonists on Mars.
      • Dan or Dynamic Albedo of Neutrons is designed to detect neutrons coming up from the martian regolith or permafrost, which have been knocked out of atoms in the subsurface by cosmic rays. It is a means of detecting the amount of subsurface water and ice. This instrument is a project of the Russian Federal Space Agency, which NASA agreed to host on Curiosity.
      • REMS or Rover Environmental Monitoring Station is a weather station reporting on daily barometric pressure, humidity, ultraviolet radiation, wind speed and direction, air temperature, and the temperature of the ground around the rover. This instrument was contributed by Spain's Centro de Astrobiologia.
      • MEDLI or Mars Science Laboratory Entry Descent and Landing Instrument is designed to collect engineering-related data during the complex and often extremely hot descent to provide spacecraft engineers with data to improve future spacecraft.
    • NASA Mars Atmosphere and Volatile Evolution or MAVEN is designed to investigate Mars' upper atmosphere with an eye to figuring out how and when Mars lost its atmosphere and once-abundant surface waters (oceans, lakes, valley networks of streams, groundwater-fed stream systems). It monitors current rates of gas losses from the top of the martian atmosphere from a highly elliptical orbit. It also collects data on Mars' ionosphere and its interactions with solar radiation and the solar wind, which will help constrain the radiation risk environment for future human-crewed missions to Mars. MAVEN launched on 18 November 2013 and entered orbit on 21 September 2014. Its orbit is highly elliptical, ranging from 150 km at periapsis to 6,000 km at apoapsis, so it will systematically travel through several distinct zones of interest in the upper atmosphere. Its instument payload is dominated by particles and fields sensors, and only includes one classic remote sensing package (IUVS below):
      • Imaging Ultraviolet Spectrograph or IUVS uses ultraviolet bands to make global characterizations of the upper atmosphere and ionosphere, estimate the altitude of the ionosphere and the exosphere, and build vertical profiles of the martian atmosphere's properties.
      • Neutral Gas and Ion Mass Spectrometer uses spectrometry to measure the upper atmosphere's major neutral molecules (helium, nitrogen [elemental and molecular], nitric oxide, oxygen [elemental and molecular], argon, carbon monoxide, and carbon dioxide) and ions (atoms and molecules with missing [cation] or surplus [anion] electrons, giving them a positive or negative charge). These measurements will help refine the composition of the martian atmosphere near the top of the homosphere (part of the atmosphere that is mixed to a fairly even composition by turbulence and winds) and the bottom of the heterosphere (where conditions produce less mixing and allow gravitational separation of molecules and ions by weight, kind of like in a salad dressing left alone in its bottle). The homosphere contains the ionosphere and the thermosphere and the upper thermosphere is the exosphere, where individual atoms and ions can escape into space without inteference by bouncing off another atom or ion.
      • Magnetometer or MAG is a very sensitive detector of magnetic fields and will measure the distribution and strength of Mars' few magnetic anomalies to help understand what happened to the planetary magnetic field about 4 billion years ago.
      • Suprathermal and Thermal Ion Composition or STATIC will measure source populations of ions in the lower ionosphere, thermal ions as these are heated in the intermediate thermosphere and some achieve escape velocity, and their acceleration as they encounter the solar wind and leave the gravitational influence of Mars entirely. It will especially focus on the ions of the water-forming gasses (hydrogen, elemental oxygen, molecular oxygen) and carbon dioxide (the predominant gas in Mars' atmosphere).
      • Solar Wind Electron Analyzer will analyze electrons in the solar wind and in Mars' ionosphere to see the effect they have in ionizing atmospheric gas molecules, boosting many of them into interplanetary space. This will help esstimate the rate of atmospheric loss through time.
      • Solar Wind Ion Analyzer or SWIA will measure the solar wind (a plasma of dissociated protons and electrons flowing from the upper atmosphere of the sun and moving with such tremendous energy that they can escape the sun's gravitational field). The idea behind SWIA is to estimate the energy the solar wind deposits in Mars' atmosphere to figure out the rates of atmospheric loss.
      • Solar Energetic Particle or SEP is a related instrument that focusses on the impact of solar wind particles with Mars' outer atmosphere.
      • Langmuir Probe and Waves or LPW will measure the density and temperature of electrons from the heart of the ionosphere up to its top. It will also evaluate the effects of aurora deposition and of plasma waves or variations in the density and motion of the solar wind on the rate of ion escape. It will try to identify where the top of the ionosphere is located (ionopause) and if there are any detached clouds of martian ions escaping in groups or pulses above the normal ionopause.
      • Extreme Ultraviolet Monitor or EUV is actually part of the LPW, but it has a distinctive task, measuring variations in the solar EUV irradiance in three different bandwidths that are especially relevant to atmospheric ionization, dissociation, and thermospheric heating. It is meant to measure solar irradiance in these wavelengths just after the solar maximum in the sunspot cycle.
    • Indian Space Research Organization (ISRO)'s Mars Orbiter Mission (MOM), aka Mangalyaan, launched 1 December 2013 and successfully entered orbit on 24 September 2014, three days after MAVEN's arrival. Like MAVEN, MOM has a very elliptical 76 hour 52 minute orbit, its periapsis at 377 km and apoapsis at 80,000 km, allowing data collection from an extensive vertical sampling frame. Its primary mission was designed to last 6-10 months, which it has already exceeded. LATE BREAKING NEWS! ISRO just reported that it lost contact with MOM, probably because its thruster propellant supplies eventually ran too low to maintain its attitude with respect to the sun for solar recharging of its power supply. The mission is now officially over. The mission has both technological goals (seeing if India can get a spacecraft to another planet and make contributions to its study with instruments designed and manufactured in India) and scientific. The scientific objectives are divided into atmospheric studies, particle environment studies (like those dominating MAVEN), and surface imaging studies. India is only the fourth country to have explored Mars (USA, USSR, and England), is the first one to enjoy an unalloyed success on its first mission there, and to have done this on the smallest Mars mission budget (about $73 million). Unfortunately, ISRO has not released much data or imagery. The orbiter carries five instruments:
      • Methane Sensor for Mars (MSM) is designed to collect evidence of methane on Mars at the parts per billion level. Methane (NH₃) is a critical question. Earth-based spectroscopy found definitive evidence of methane plumes in the Northern Lowlands east of Arabia Terra, the Nili Fossæ area, and southeast Syrtis Major. These were particularly common in the spring and summer, as one might expect with microbial activity near permafrost. Methane can also emanate from volcanic processes (and Syrtis Major contains volcanoes). Curiosity, however, had not found a single trace of methane after a year on Mars. In a surprise development a year later, it did detect a sudden tenfold increase in methane, which repeated several times in two months! So, the highly sensitive MSM will be crucial to helping resolve this contradiction and is, thus, likely to be the most important contribution of MOM.
      • Lyman-Alpha Photometer (LAP), which will measure the balance between ordinary hydrogen and its heavier isotope, deuterium. Exospheric loss of hydrogen is greater than that of the heavier deuterium, which is held more strongly by gravity to Mars. An imbalance from the expected ratio represents the loss of water (H₂O).
      • Mars Exospheric Neutral Composition Analyzer (MENCA) is designed to study the composition of the martian exosphere, from which molecules and ions escape into space.
      • Thermal Infrared Imaging Spectrometer (TIS) will be used to map variations in the temperature of martian surfaces
      • Mars Colour Camera (MCC) will take images of Mars' surface and those of its two moons and will be used as a context imager for the other instruments.
    • NASA's Interior exploration using Seismic Investigations, Geodesy, and Heat Transport) or InSight lander will provide "insights" on Mars' deep interior, using a seismometer, a thermal probe, and a system to track wobble in the planet's rotation to discern its interior mass distribution and structure. It also features a robotic arm for deployment of the other instruments and this supports an instrument deployment camera. There is also a context camera mounted under the deck facing the instruments during deployment and operation. The lander was placed in Elysium Planitia near the great dichotomy.
      • SEIS, the Seismic Experiment for Interior Structure, is a dome set out on the surface beside the lander. It detects vibrations from marsquakes or from meteorite impacts. It also contains wind, pressure, temperature, and magnetic field sensors to help calibrate the seismometer's measurements for the effects of windstorms and other atmospheric phenomena.
      • HP³, the Heat Flow and Physical Properties Package, was supposed to drill down about 5 m and measure heat flow from the martian interior for insights on its source. It was also supposed to measure how quickly heat generated by the instrument itself would dissipate to find out how conductive the crust material is. This instrument was unable to drill past the resistance of a soil type not encountered before on previous missions.
      • RISE, the Rotation and Interior Structure Experiment, uses two radio antennas to measure the precise location of the lander at all times to determine how much its axis wobbles during rotation and revolution. This works by reflecting a signal sent from Earth constantly, allowing measurement of a kind of Doppler shift as the planet wobbles. This helps constrain just how large the martian core is, how much of it is still liquid, and what its composition is (what else is in there besides iron?).

    • NASA's Mars 2020 Mission Perseverance Rover is built on the same rover design as MSL Curiosity and, like it, had to be landed in the same exotic sky crane system. It contains different instruments, however, because it is pursuing different science goals.
      • Mastcam-Z. Like Curiosity's Mastcam, this is a high definition video and panoramic camera mounted roughly at the height of a tall person (2 m) with twin cameras some 24 cm apart that can create 3-d images of the surrounding terrain and atmosphere above (like our own paired eyes can only with more parallax). Unlike Curiosity's Mastcam, this one has zoom capability. It serves as a context camera for the other, higher resolution instruments.
      • SuperCam is also mounted on the 2 m mast. It contains a camera, a laser (death ray <G>), and a spectrometer. It is designed to identify the chemical makeup of rocks and soil targets from tiny points that can be as far as 7 m away! It zaps these small targets with its laser, causing dust and debris to fly off and expose the underlying surface, and then subject it to spectroscopy that can identify both elements and molecules and infer mineral composition. It is specifically able to identify carbon-bearing compounds that may reflect the activities of ancient life in the lacustrine and delta environments of Jezero Crater.
      • Planetary Instrument for X-ray Lithochemistry, or PIXL. PIXL is mounted on the turret of Perseverance's robotic arm designed for contact and near contact with promising targets. It contains an extreme close-up camera (as in grain of sand scale). It also features an X-ray fluorescence spectrometer that can identify the elemental composition of such small targets. This is a partial replacement for the elemental analysis capabilities of the APXS instrument on Curiosity, Opportunity, Spririt, and Sojourner.
      • Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, or SHERLOC is also mounted on the robotic arm. SHERLOC does spectroscopy utilizing a Deep Ultraviolet laser applied to induce fluorescence and Raman scattering in small targets that are simultaneously imaged with a black and white context camera and the WATSON color camera. WATSON is almost identical to the MAHLI "hand-lens" camera on Curiosity. The SHERLOC package of spectrosope and cameras is able to detect the biologically important carbon, hydrogen, nitrogen, oxygen, phosphorous, and sulfur, which together make up the vast majority of living tissue.
      • Mars Environmental Dynamics Analyzer, or MEDA sensor is mounted on the body of the rover and the base of the mast and functions as a weather station, measuring temperature, humidity, dust abundance and size distribution, and wind speed and direction.
      • Radar Imager for Mars' Subsurface Experiment, or RIMFAX is mounted in the back of the rover's body, with a nadir-pointing antenna on the rear exterior. It is a ground-penetrating radar instrument that emits radar signals as the rover moves across the surface. It collects both shallow and deep radar reflections every 10 cm and is the first instrument to capture high resolution stratigraphic data from as deep as 10 m below the rover.
      • Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE is a proof-of-concept gizmo designed to produce oxygen on Mars. In the future, the production of oxygen could create breathable air for living spaces on Mars and also the oxidant for rocket fuel. Being able to produce fuel on Mars for return trips would drastically cut the weight requirements for launching crewed missions to Mars. MOXIE is located in the rover's body toward the right front. It collects carbon dioxide from the martian atmosphere, electrochemically dissociates it into oxygen and carbon monoxide, and, after analyzing the purity of the oxygen produced, vents both it and the carbon monoxide into the martian air afterwards.
    • Emirates Mars Mission, or Hope is the first Mars mission from the Arab world, designed and managed by the United Arab Emirates Space Agency. Hope was launched from Japan on 20 July 2020 and entered orbit around Mars on 9 February 2021. It features an unusual orbit around the equator every 55 hours, ranging from 20,000 km to 43,000 km, designed to keep the entire planet in view at all times. This will permit global analysis of weather processes and climate, examine how weather affects the escape of hydrogen and oxygen, and understanding of the interactions of the lower atmosphere (where weather happens) and the upper atmosphere (where light gasses sputter into The Final Frontier). Hope houses three instruments: a camera and two spectrometers.
      • Emirates Mars Infrared Spectrometer, or EMIRS is a thermal infrared spectrometer suitable for the study of the lower atmosphere's dust, ice clouds, water vapor, and temperature distribution
      • Emirates Exploration Imager, or EXI is a high resolution visible light and ultraviolet imager, which can measure the optical depth of water ice and ozone in the martian atmosphere, as well as take visible light images of Mars
      • Emirates Mars Ultraviolet Spectrometer or (EMUS) is suitable for analyzing the density and viariability of carbon monoxide, hydrogen, and oxygen in the outermost atmosphere (thermosphere and exosphere) and should help constrain the amount of loss in these gasses to space. A recent study entailed a coördination between NASA's MAVEN and Hope's EMUS to quantify this loss and to image aurorae on Mars!
    • The China National Space Agency (CNSA) Tianwen-1 Mission is the second Chinese Mars mission (CNSA had previously worked with the RUssian space agency and the Planetary Society on the ill-fated Phobos-Grunt mission to provide the Yinghuo-1 Mars orbiter, but Phobos-Grunt failed to escape Earth's gravity in 2011). Tianwen-1 is China's first independent mission to Mars, launching successfully on 23 July 2020 and achieving Mars orbit on 10 February 2021. Its lander-rover combination landed on Utopia Planitia on 15 May 2021. This ambitious mission includes fourteen instruments, eight on the Tianwen-1 orbiter and six on the Zhurong rover. The CNSA web site is thin on technical information with no links to the instruments, so I had to resort to Wikipedia for much of the description below....
      • Tianwen-1 orbiter:
        • Moderate Resolution Imaging Camera or MoRIC provides color photographs with 100 m spatial resolution
        • High Resolution Imaging Camera or HiRIC offers spatial resolution of 2.5 m in panchromatic mode and 10 m in color mode
        • Mars Orbiter Magnetometer or MOMAG is designed to map the remnant magnetic field of Mars
        • Mars Mineralogical Spectrometer or MMS covers the visible and near infrared wavelengths from 0.45 to 3.4 microns. It is intended to study the composition of the martian regolith and subsurface structure.
        • Mars Orbiter Scientific Investigation Radar or MOSIR focusses on water and ice in the martian surface and subsurface
        • Mars Ion and Neutral Particle Analyzer or MINPA focusses on the flux of ions in the orbital and space environment, detection of different kinds of ions and their density, velocity, and temperature
        • Mars Enegetic Particle Analyzer or MEPA works on establishing the the flow, composition, and energy distribution of electrons, protons, alpha-particles, and ions
        • It contains a "selfie-taking" camera system mounted on a flexible arm. This instrument has been dubbed the Mars Orbiter Status Monitoring Sensor or MOSMOS.
      • Tianwen-1 lander basically functioned as a vehicle to deliver the independent Zhurong rover, with no instrumentation other than the Mars Emergency Beacon to broadcast the event of a crash and capture engineering data to improve future missions if this one failed.
      • Zhurong rover
        • Mars Rover Penetrating Radar or RoPeR is a ground-penetrating radar designed to visualize the martian subsurface down to about 100 m, similar to the RIMFAX GPR on the Perseverance Rover, which targets shallower subsurface materials at a very high spatial and temporal resolution.
        • Mars Rover Magnetometer or RoMAG will complement the MOMAG instrument on the Tianwen-1 orbiter by capturing local and fine scale crustal magnetism signals
        • Mars Climate Station or MCS, which is sometimes referred to as the Mars Meteorological Measurement instrument or MMM. This is a weather station reporting on temperature, pressure, wind velocity, and a microphone
        • Mars Surface Compound Detector (MarSCoDe) is another laser "death ray" instrument like the ones on Perseverance and Curiosity. It zaps targets with a laser (laser-induced breakdown spectroscopy) and captures infrared spectra.
        • Multispectral Camera (MSCam), mounted on the mast, is used in conjunction with MarSCoDe in investigation of the mineral composition of MarSCoDe's targets and the subsurface water environment and water-altered secondary minerals
        • Navigation and Topography Cameras (NaTeCam) is a stereoscopic camera system also mounted on the mast to provide detailed images in parallax for the construction of topographic models and evaluation of hazards to the rover, as well as investigations focussed on inferring geological structures from surface expressions.
      • Tianwen-1 Depoloyable Cameras (2) released at critical points during the cruise to Mars and during orbit insertion in order to image the mission from a distance, test a radio connection with the orbiter, and then proceed to image Mars in flyby mode.
      • Tianwen-1 Remote Camera (1) was deployed from the lander in order to take a group photo of the Zhurong rover and the Tianwen-1 lander before their separation, kind of a PR shot. The "selfie" tradition on Mars continues...