Mars Definition and 136 Discussions

Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, being larger than only Mercury. In English, Mars carries the name of the Roman god of war and is often referred to as the "Red Planet". The latter refers to the effect of the iron oxide prevalent on Mars's surface, which gives it a reddish appearance distinctive among the astronomical bodies visible to the naked eye. Mars is a terrestrial planet with a thin atmosphere, with surface features reminiscent of the impact craters of the Moon and the valleys, deserts and polar ice caps of Earth.
The days and seasons are comparable to those of Earth, because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are similar. Mars is the site of Olympus Mons, the largest volcano and highest known mountain on any planet in the Solar System, and of Valles Marineris, one of the largest canyons in the Solar System. The smooth Borealis basin in the Northern Hemisphere covers 40% of the planet and may be a giant impact feature. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Mars trojan.Mars has been explored by several uncrewed spacecraft. Mariner 4 was the first spacecraft to visit Mars; launched by NASA on 28 November 1964, it made its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. The Soviet Mars 3 mission included a lander, which achieved a soft landing in December 1971; however, contact was lost seconds after touchdown. On 20 July 1976, Viking 1 performed the first successful landing on the Martian surface. On 4 July 1997, the Mars Pathfinder spacecraft landed on Mars and on 5 July released its rover, Sojourner, the first robotic rover to operate on Mars. The Mars Express orbiter, the first European Space Agency (ESA) spacecraft to visit Mars, arrived in orbit on 25 December 2003. In January 2004, NASA's Mars Exploration Rovers, named Spirit and Opportunity, both landed on Mars; Spirit operated until 22 March 2010 and Opportunity lasted until 10 June 2018. NASA landed its Curiosity rover on August 6, 2012, as a part of its Mars Science Laboratory (MSL) mission to investigate Martian climate and geology. On 24 September 2014, the Indian Space Research Organisation (ISRO) became the fourth space agency to visit Mars when its maiden interplanetary mission, the Mars Orbiter Mission spacecraft, arrived in orbit. The United Arab Emirates became the fifth to successfully undertake a mission to Mars, having inserted an orbiter into the Martian atmosphere on 9 February 2021. China National Space Administration (CNSA)'s Tianwen-1 spacecraft arrived in Martian orbit on 10 February 2021. NASA's Perseverance rover and Ingenuity helicopter successfully landed on Mars on 18 February 2021. Ingenuity successfully completed the first powered controlled flight by an aircraft on any planet besides Earth on 19 April 2021, taking off vertically, hovering and landing on Mars. On 14 May 2021, CNSA's Tianwen-1 lander and Zhurong rover successfully landed on Mars. Zhurong rover was successfully deployed on 22 May 2021, which makes China the second country to successfully deploy a rover on Mars, after the United States.There are investigations assessing the past habitability of Mars, as well as the possibility of extant life. Astrobiology missions are planned, such as the European Space Agency's Rosalind Franklin rover. Liquid water on the surface of Mars cannot exist due to low atmospheric pressure, which is less than 1% of the atmospheric pressure on Earth, except at the lowest elevations for short periods. The two polar ice caps appear to be made largely of water. The volume of water ice in the south polar ice cap, if melted, would be sufficient to cover the planetary surface to a depth of 11 metres (36 ft). In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior.Mars can easily be seen from Earth with the naked eye, as can its reddish coloring. Its apparent magnitude reaches −2.94, which is surpassed only by Venus, the Moon and the Sun. Optical ground-based telescopes are typically limited to resolving features about 300 kilometres (190 mi) across when Earth and Mars are closest because of Earth's atmosphere.

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  1. Isopod

    B Could anything heat back up the core of Mars?

    My understanding of why Mars lost its atmosphere was because it cooled down too much internally and that when this happened, the planet lost its magnetic field that helped protect it from solar winds (which then ended up stripping away the planets atmosphere). Is there anything that people could...
  2. T

    Could Mars have supported life? NASA challenge wants your help

    Deadline April 18, 2022 Competition Eligibility at: HeroX Challenge page: Brief article: Good Luck, and have Fun! Tom
  3. Margarita0076

    Engineering Assembly Programming (MIPS): Convert BCD to Decimal

    I have this code which convert decimal number to binary number, but I do not understand how representation 8762 like 1000 0111 0110 0010. 8 7 6 2 1000 0111 0110 0010 .data strmsg: .asciiz "please Enter a decimal number: " .text #main method .globl main #main function main...
  4. D

    Stargazing Better than Mars Colonization in many aspects.

    Venus is not at the top of the priority list when it comes to the colonizing of space. Mars mostly takes the top spot but when checked deeply, it is very comparable to Mars Colonization and in some aspects it is even better than Mars Colonization. [Spammy link redacted by the Mentors]
  5. Electrical

    How scientists calculated the weight of Mars

    How scientists calculated the weight of Mars to be 6.39 × 10^23 kg?
  6. Miles Behind

    Simple atmospheric question re: Mars

    Assuming that both the Earth and Mars's atmospheric pressure follows an exponential curve, how many kilometers deep would the average bore-hole on Mars need to be in order to arrive at a depth where the atmospheric pressure was 0.35 bar or approximately 5 psi? What about 0.7 bar?
  7. Edge5

    I Opal crystals on Mars

    People found silica opals exist on the planet Mars, what does this imply about geochemical conditions on Mars?
  8. F

    Lift-off from Mars

    Watching "Mars" on National Geographics I try to calculate what the cost would be to bring anything usefull back to Earth. More specifically I wonder what fuel-payload ratio a rocket could have when lifting off from Mars. I want to use Tsiolkovsky's rocket equation Δv = ve ln(m0/mf) or Δv =...
  9. T

    NASA NASA Challenge - CO2 Conversion

    NASA is looking for a process to use CO2 as a Carbon source on Mars; ultimate goal is to use the Carbon in the synthesis of other products. $50,000 prize. Open to U.S. citizens, permanent residents, and U.S. business entities, work must be done in the U.S...
  10. A

    I Would going to the Moon delay going to Mars?

    Former 'Mars czar' in a interview: Read more at: But would it? Surely the Moon is a perfect launchpad for Mars, a testbed, and a supply base? Going from Earth direct is a truly huge task. From an established Lunar...
  11. Delta2

    B Water colour in Mars

    I guess water in earth , in big lakes or seas, looks blue because the earth's sky is blue and the water's surface reflects the sky. Now if there would be some big lake of water at Mars, how the water surface colour would be? I guess the colour of Mar's sky which is red (right or wrong?) It is...
  12. F

    I Liquid water reservoir reported under Mars polar cap

    The analysis is based on 29 radar profiles collected between May 2012 and December 2015. The identified region is about 20-km wide. The report acknowledges the results are consistent with with water or water-laden sediments. A brief discussion on the BBC (with no citations) asserted that...
  13. DrClaude

    I Organic molecules found on Mars

    NASA Curiosity rover hits organic pay dirt on Mars Scientific article: Organic matter preserved in 3-billion-year-old mudstones at Gale crater, Mars
  14. Craftek_Ana

    B Traveling to Mars and time dilation

    If/when we go to Mars how will we deal with time dilation due to the gravitational differences between the two planets?
  15. BlackholeGirl

    NASA [NASA] Cosmological projects instead of space exploration

    NASA decided to stop *WFIRST and concentrate on Mars project (send humans to Mars). What do you think about it? In my opinion, since a lot of ventures have begun space developments such as SpaceX and this proves that rockets make money, NASA should tackle WFIRST. Generally, we cannot earn...
  16. Phantoful

    How do I solve for the angle, as a function?

    Homework Statement Homework Equations [/B] The two equations in the image, as well as (maybe) standard vector operations like dot product, cross product. The Attempt at a Solution [/B] So, I've tried to do what my instructor suggested and put everything in terms of Earth (Using RE and TE...
  17. Rednecknav

    I Moon vs Earth for launch to Mars

    Problem - we have to use large amounts of fuel/propellant to exit the earths atmosphere to enter earth orbit, the moon or other planets.... Solution - would it not make sense to launch from a base on the moon? Problems I see, potentially.... 1) Is the moon’s orbit around earth problematic for...
  18. mfb

    SpaceX SpaceX Falcon Heavy Launch

    All the Wild dang We're Going to Do in Space and Physics in 2018 (forum censors the original title) Featuring all the interplanetary probes and various missions and milestones closer to Earth, the Event Horizon Telescope, Gaia, and a couple of things not directly related to space or spaceflight...
  19. mr1batman

    B Distance between the Earth and The Moon

    we know that the moon is far away the distance between us and the moon can fit all the other 7 planets and some small dwarf planets but how ? it would take us 3 days to reach the moon and the spacecraft were traveling in at least 240,000 miles it should take us more than a year to reach the...
  20. T

    I Where in our solar system are asteroids that contain ammonia

    Hi! I'm doing a research project titled "Is it possible to colonise Mars?" I'm currently researching how to raise the temperature and pressure - and i've discovered to do this that re-directing asteroids towards Mars containing Ammonia would be vital. However, where do these asteroids that...
  21. shihab-kol

    B Position of the asteroid belt

    The asteroid belt is present between mars and Jupiter but why is it spaced out like that? Why not between some other planets?
  22. Singlau

    B Mars Dust Storms

    Recently I read a book about Mars, and it says that global sandstorm blows from southern hemisphere to northern hemisphere at perihelion. It's because the southern part is more heated at that position and the closer distance to sun gives it a high temperature, thus sublimating large amout CO2 in...
  23. N

    A Would a larger Martian moon create a stronger magnetic field

    I have read a previous forum discussing the possibility of creating a stronger magnetic field on Mars using tidal forces by putting a larger moon in orbit around Mars. My question is how large of an object would it have to be compared to Mars and how distant would its orbit need to be from the...
  24. ramzerimar

    SpaceX About the SpaceX Interplanetary Transport System

    I know mars colonization is a hot topic these days, and there are a lot of threads on this topic, but I would like to discuss specifically the SpaceX Interplanetary Transport System. There's a video on the subject here. On a recent thread that I posted here, some people came to the conclusion...
  25. N

    Changing Venus' Atmosphere

    I thought a bit about the prospect of terraforming other worlds starting with the ones closest to us, Mars and Venus. Personally even though I don't mind the hype over Mars, I prefer thinking of Venus as the main target for terraforming. it's just a lot more tempting. for example: It's surface...
  26. A

    I Great oppositions of Mars

    Why do the Great oppositions of Mars always happen at the same time of the year? What is that time?
  27. G

    Mushrooms and forests of Mars

    I'm going to write a space opera, a part of it involves Mars. I wonder about the plausibility level of my following imaginations. "She descanded on the space elevator. The landscape outside looked like a mushroom field. There were transparent and red ones. The hats of the former ones were big...
  28. E

    I How does mars have a magnetic field, with a cooled core?

    I have been studying astronomy and astrophysics for about 2 years now, though on my own time and by my self. A recent question came into my mind, Can arctic planets exist close to their star? Now, in my understanding of planetary science, in order for a planet to be cool and close to the sun, it...
  29. Raptor112

    Carbon Dioxide in the Martian Ice Caps

    Homework Statement The Viking landers on Mars measured a seasonal change in surface pressure of 2.5 mb due to the variation in the seasonal extent of the ice caps. Ignoring any elevation variations on the surface of Mars, calculate the difference in the total mass of CO2 in both ice caps...
  30. A

    Aerostat on Venus vs Surface Colony on Mars

    Idk where i picked this up, but there is one other plausible colony destination for humans: Venus. After a few trips on the net, i've come to the "Aerostat on Venus" side instead of a colony on mars. I'll mention some of the reasons i've picked up as to why: 1. Tons of CO2, we can use that. 2...
  31. R

    Space Travel to mars

    So off to Mars we go. But really how are we going to get there? The most expensive part of space travel is overcoming atmosphere. So you could say the biggest obstacle of space travel is Earth travel. It takes virtually no energy to cross space but it takes massive amounts to get into space...
  32. R

    About the resupply missions in "The Martian"

    Two instances were discussed in the film where unmanned cargo ships were mentioned to send up supplies to extend the time Whatney or the crew of the Hermes could survive. This brought back painful memories while watching the movie. It's such an obvious answer. In the space shuttle Columbia...
  33. @PK nd

    Life on mars

    Does discovery of flowing water on mars means that life even in microscopic form is possible ?????
  34. chi_rho

    Travelling to Mars at constant velocity? Weightless?

    If I'm travelling on a spaceship at a constant velocity (say 10000 m/s) towards Mars will I feel weightless, or will I feel nearly weightless because I will still be slightly affected by gravity? I know that when astronauts are in the ISS they feel weightless because they are in a constant...
  35. Dr.Physics

    NASA NASA Mars Manned Mission

    I am very interested in the Astronautical area of science; however I am still in high school so I don't get a lot of time to read up on the latest news about this future mission. This is why I am eager to be filled in on the latest news about the mission. I am looking to know about the...
  36. C

    Did a Giant Impact Make the Martian Moons?

    by Ken Croswell The Martian moons look like asteroids—dark, crater-pocked, and potato-shaped—suggesting Mars had snatched them from the nearby asteroid belt. But now planetary scientists have conducted the first computer simulations that bolster a controversial alternative idea: The satellites...
  37. BilboBombadillo

    Help with circular velocity question (unit conversions?)

    Homework Statement Consider a satellite in circular low Mars orbit 300km above the planetary surface. R = 3396km M = 6.419 x 1023kg G = 6.674 x 10-11m3/kg/s2 Find the orbital velocity of the satellite (using the given values, I assume, as there is some inaccuracy in the real-life mass value...
  38. Kelson Adams

    Physics We colonize Mars, emerging industries?

    Let's say we colonize Mars today. What will some of the leading emerging industries be? I can imagine the energy sector (nuclear power, etc.), heavy materials sector (mining, etc.) and communications sector (internet, etc.) will be robust. What emerging industries could you imagine forming on...
  39. edpell

    Going to Mars

    There is a lot of talk about going to Mars. But not a lot of talk about how to keep the people alive on Mars. I am hoping we can talk about that here.
  40. G

    Relationship between characteristic energy and delta-v

    Firstly, apologies if this is in the wrong thread. I'm currently writing a presentation on the physics of getting a spacecraft from Earth to Mars in the near future. In my research I've come up against Porkchop plots which seem to plot contours of equal characteristic energy so you can find out...
  41. T

    In depth Mars flight trajectory studies

    Can anyone point me in the direction of any published scientific work involving the study of Earth to Mars flight trajectories? I am thinking of researching this topic for a project and I would like to know about the work that has already been done.
  42. B0b-A

    What's the scale on Mars rover "Microscopic Imager" images ?

    What's the scale on Mars rover Opportunity's "Microscopic Imager" images ? I'm trying to work out if the Martian "fossil" shown could be the impression of a cross-head-screw ...
  43. R

    Science-Fiction: What could impede the use of electricity on half of Mars?

    Hello. I’m a new addition to the board, and if I’ve posted in the wrong place or this is otherwise unwelcome, please PM me and let me know. I’m a writer and I’m working on a science-fiction novel set on Mars in the distant future. I can gather most of the information on the planet, the...
  44. T

    Giving Mars a magnetic field

    In my opinion, any attempt to colonise Mars would require a sustainable atmosphere. Without a magnetic field; This atmosphere will quickly be stripped away by solar winds. Now if we were to "Build" a large enough moon orbiting Mars by towing asteroids into Martian orbit and allowing accretion...
  45. Alesak

    NASA NASA picks another Mars flight to explore its core Aww. Titan Mare Explorer looks way more exciting to me, even if we had results only when I'm 37 years old.
  46. G

    Nobel laureate gerard 't hooft supports dutch manned mission to mars

    i'm highly skeptical that the dutch can pull this off. there are still so many obstacles to putting people on mars that i seriously doubt a country of about 25 million like the netherlands could pull it off and this in...
  47. B

    NASA NASA Curiosity Rover Mars entry parachute deceleration question

    Can someone please point me to a deceleration graph over the 7 minutes of terror from the 13,000 mph re-entry speed through to the parachute release and landing of the Curiosity Rover on Mars? Thanks very much. :smile: PS: Mods please feel free to move this topic to the appropriate forum...
  48. D

    What is the minimum distance between earth and mars while rotating in their orbits?

    What is the minimum distance between earth and mars in course of their rotation in orbits? I need the derivation and analytic calculation. If we assume the plane of rotation is different for earth and mars, the problem become to complicated. So the orbits may be assumed co-planner.Please...
  49. KenJackson

    Positions of stars as seen from Mars-different than from Earth?

    Positions of stars as seen from Mars--different than from Earth? I'm reading a novel that says , "On Mars the stars seemed a bit out of place, not in their correct position[s]." Could that be true? I suspect that if you disregard anything within our solar system, the stars would be so far...
  50. W

    If mars had more density

    What would mars be like if it had 50% more density? Like what would be occuring inside, on the surface and the atmosphere? Would there be no water because of the extra density, hotter core, more atmosphere or any other processes?