Climate of Mars - Wikipedia, The Free Encyclopedia

3/5/14 Climate of Mars - Wikipedia, the free enc\clopedia

1/20en.wikipedia.org/wiki/Climate_of_Mars

Mosaic image of Mars as seen by Viking 1,

22 February 1980

ClimaWe of MaUVFrom Wikipedia, the free encyclopedia

FXUWheU infoUmaWion: AWmoVpheUe of MaUV

The climaWe of MaUV has been an issue off scientific curiosity forcenturies, not least because Mars is the only terrestrial planet whosesurface can be directly observed in detail from the Earth with helpfrom a telescope.

Although Mars is smaller at 11% of Earth's mass and 50% fartherfrom the Sun than the Earth, its climate has important similarities,such as the polar ice caps, seasonal changes and the observablepresence of weather patterns. It has attracted sustained study fromplanetologists and climatologists. Although Mars's climate hassimilarities to Earth's, including seasons and periodic ice ages, thereare also important differences such as the absence of liquid water(though frozen water exists) and much lower thermal inertia. Mars'atmosphere has a scale height of approximately 11 km (36,000 ft),60% greater than that on Earth. The climate is of considerablerelevance to the question of whether life is or was present on theplanet, and briefly received more interest in the news due to NASAmeasurements indicating increased sublimation of the south polar icecap leading to some popular press speculation

that Mars was undergoing a parallel bout of global warming.[1]

Mars has been studied by Earth-based instruments since as early as the 17th century but it is only since theexploration of Mars began in the mid-1960s that close-range observation has been possible. Flyby and orbitalspacecraft have provided data from above, while direct measurements of atmospheric conditions have beenprovided by a number of landers and rovers. Advanced Earth orbital instruments today continue to provide someuseful "big picture" observations of relatively large weather phenomena.

The first Martian flyby mission was Mariner 4 which arrived in 1965. That quick two day pass (July 1415, 1965)was limited and crude in terms of its contribution to the state of knowledge of Martian climate. Later Marinermissions (Mariner 6, and Mariner 7) filled in some of the gaps in basic climate information. Data based climatestudies started in earnest with the Viking program in 1975 and continues with such probes as the MarsReconnaissance Orbiter.

This observational work has been complemented by a type of scientific computer simulation called the Mars

General Circulation Model.[2] Several different iterations of MGCM have led to an increased understanding ofMars as well as the limits of such models. Models are limited in their ability to represent atmospheric physics thatoccurs at a smaller scale than their resolution. They also may be based on inaccurate or unrealistic assumptionsabout how Mars works and certainly suffer from the quality and limited density in time and space of climate datafrom Mars.

ConWenWV

1 Historical climate observations

2 Martian paleoclimatology



2 MaUWian paleoclimaWolog\

3 WeaWheU

4 CloXdV

5 TempeUaWXUe

6 AWmoVpheUic pUopeUWieV and pUoceVVeV

6.1 LoZ aWmoVpheUic pUeVVXUe

6.2 Wind6.3 EffecW of dXVW VWoUmV

6.3.1 SalWaWion

6.4 RepeaWing noUWheUn annXlaU cloXd

6.5 MeWhane pUeVence

6.6 CaUbon dio[ide caUYing

7 MoXnWainV

8 PolaU capV

9 SolaU Zind

10 SeaVonV

11 EYidence foU UecenW climaWic change

11.1 AWWUibXWion WheoUieV

11.1.1 PolaU changeV11.1.2 SolaU iUUadiance

12 ClimaWe ]oneV13 CXUUenW miVVionV

14 FXWXUe miVVionV15 See alVo16 RefeUenceV

17 FXUWheU Ueading18 E[WeUnal linkV

Historical climate observations

Giancomo MiUaldi deWeUmined in 1704 WhaW Whe VoXWheUn cap iV noW cenWeUed on Whe UoWaWional pole of MaUV.[3]

DXUing Whe oppoViWion of 1719, MiUaldi obVeUYed boWh polaU capV and WempoUal YaUiabiliW\ in WheiU e[WenW.

William HeUVchel ZaV Whe fiUVW Wo dedXce Whe loZ denViW\ of Whe MaUWian aWmoVpheUe in hiV 1784 papeU enWiWled Onthe remarkable appearances at the polar regions on the planet Mars, the inclination of its a[is, the positionof its poles, and its spheroidal figure; Zith a feZ hints relating to its real diameter and atmosphere. WhenWZo fainW VWaUV paVVed cloVe Wo MaUV ZiWh no effecW on WheiU bUighWneVV, HeUVchel coUUecWl\ conclXded WhaW WhiV meanW

WhaW WheUe ZaV liWWle aWmoVpheUe aUoXnd MaUV Wo inWeUfeUe ZiWh WheiU lighW.[3]

HonoUe FlaXgeUgXeV 1809 diVcoYeU\ of "\elloZ cloXdV" on Whe VXUface of MaUV iV Whe fiUVW knoZn obVeUYaWion of

MaUWian dXVW VWoUmV.[4] FlaXgeUgXeV alVo obVeUYed in 1813 VignificanW polaU ice Zaning dXUing MaUWian VpUingWime.HiV VpecXlaWion WhaW WhiV meanW WhaW MaUV ZaV ZaUmeU Whan eaUWh pUoYed inaccXUaWe.

Martian paleoclimatolog\



Martian Morning Clouds - Viking

Orbiter 1 (taken in 1976) - (February

12, 2014).

Prior to any serious examination of Martian paleoclimatology one has to agree on terms, especially broad terms ofplanetary ages. There are two dating systems now in use for Martian geological time. One is based on craterdensity and has three ages: Noachian, Hesperian, and Amazonian. The other is a mineralogical timeline, also havingthree ages: Phyllocian, Theikian, and Siderikian.

Recent observations and modeling are producing information not only about the present climate and atmosphericconditions on Mars but also about its past. The Noachian-era Martian atmosphere had long been theorized to becarbon dioxide rich. Recent spectral observations of deposits of clay minerals on Mars and modeling of clay

mineral formation conditions[5] have found that there is little to no carbonate present in clay of that era. Clayformation in a carbon dioxide rich environment is always accompanied by carbonate formation, though thecarbonate may later be dissolved by volcanic acidity.

The discovery of water-formed minerals on Mars, including hematite and jarosite, by the Opportunity rover andgoethite by the Spirit rover, has led to the conclusion that climatic conditions in the distant past allowed for free-flowing water on Mars. The morphology of some crater impacts on Mars indicate that the ground was wet at the

time of impact.[6] Geomorphic observations of both landscape erosion rates[7] and Martian valley networks[8] alsostrongly imply warmer, wetter conditions on Noachian-era Mars (earlier than about 4 billion years ago). However,chemical analysis of Martian meteorite samples suggests that the ambient near-surface temperature of Mars has

most likely been below 0 C for the last four billion years.[9]

Some scientists maintain that the great mass of the Tharsis volcanoes has had a major influence on the climate ofMars. Erupting volcanoes give off great amounts of gas, mainly water vapor and CO2. Enough gas may have been

released by volcanoes to have made the earlier Martian atmosphere thicker than Earth's. The volcanoes could alsohave emitted enough H2O to cover the whole Martian surface to a depth of 120 m (390 ft). CO2 is a greenhouse

gas that raises the temperature of a planet: it traps heat by absorbing infrared radiation. So Tharsis volcanoes, bygiving off CO2, could have made Mars more Earth-like in the past. Mars may have once had a much thicker and

warmer atmosphere, and oceans and/or lakes may have been present.[10] It has, however, proven extremelydifficult to construct convincing global climate models for Mars which produce temperatures above 0 C at any

point in its history,[11] though this may simply reflect problems in accurately calibrating such models.

WeaWheU

Mars' temperature and circulation vary from year to year (as expectedfor any planet with an atmosphere). Mars lacks oceans, a source of muchinter-annual variation on Earth. Mars Orbiter Camera data beginning in

March 1999 and covering 2.5 Martian years[12] show that Martianweather tends to be more repeatable and hence more predictable thanthat of Earth. If an event occurs at a particular time of year in one year,the available data (sparse as it is) indicate that it is fairly likely to repeatthe next year at nearly the same location give or take a week.

On September 29, 2008, the Phoenix lander took pictures of snow fallingfrom clouds 4.5 km above its landing site near Heimdall crater. Theprecipitation vaporized before reaching the ground, a phenomenon called

virga.[13]

CloXdV



Animation of ice clouds moving above the

Phoenix landing site over a period of ten

minutes (August 29, 2008).

Planet Mars most abundant gases (Curiosity

rover, Sample Analysis at Mars device, October

2012).

Mars' dust storms can kick up fine particles in the atmospherearound which clouds can form. These clouds can form very high

up, up to 100 km (62 mi) above the planet.[14] The clouds are veryfaint and can only be seen reflecting sunlight against the darkness ofthe night sky. In that respect, they look similar to the mesosphericclouds, also known as noctilucent clouds on Earth, which occurabout 80 km (50 mi) above our planet.

Temperature

Differing values have been reported for the average temperature on

Mars,[15] with a common value being 55 C (67 F).[16] Surfacetemperatures may reach a high of about 20 C (68 F) at noon, atthe equator, and a low of about 153 C (243 F) at the

poles.[17] Actual temperature measurements at the Viking landers'site range from 17.2 C (1.0 F) to 107 C (161 F). Thewarmest soil temperature on the Mars surface estimated by the

Viking Orbiter was 27 C (81 F).[18] The Spirit rover recorded amaximum daytime air temperatures in the shade of 35 C (95 F), and regularly recorded temperatures well above

0 C (32 F), except in winter.[19]

It has been reported that "On the basis of the nightime air temperature data, every northern spring and earlynorthern summer yet observed were identical to within the level of experimental error (to within 1 C)" but that the"daytime data, however, suggest a somewhat different story, with temperatures varying from year-to-year by up to

6 C in this season.[20] This day-night discrepancy is unexpected and not understood". In southern spring andsummer, variance is dominated by dust storms which increase the value of the night low temperature and decrease

the daytime peak temperature.[21] This results in a small (20 C) decrease in average surface temperature, and a

moderate (30 C) increase in upper atmosphere temperature.[22]

Atmospheric properties and processes

LoZ atmospheric pressure

The Martian atmosphere is composed mainly of carbondioxide and has a mean surface pressure of about 600pascals (Pa), much lower than the Earth's 101,000 Pa. Oneeffect of this is that Mars' atmosphere can react much morequickly to a given energy input than that of Earth's

atmosphere.[23] As a consequence, Mars is subject tostrong thermal tides produced by solar heating rather than agravitational influence. These tides can be significant, beingup to 10% of the total atmospheric pressure (typically about50 Pa). Earth's atmosphere experiences similar diurnal andsemidiurnal tides but their effect is less noticeable becauseof Earth's much greater atmospheric mass.



Curiosit\ rover's parachute flapping in

the Martian wind (HiRISE/MRO)

(August 12, 2012 to January 13,

2013).

Martian Dust Devil in Amazonis

Planitia (April 10, 2001) (also

(http://www.nasa.gov/mission_pa

ges/MRO/multimedia/pia15116.ht

ml)) (video (02:19)

(http://www.youtube.com/watch?

v=0t0LWFHB8Qo)).

Although the temperature on Mars can reach above freezing(0 C (32 F)), liquid water is unstable over much of the planet, as the atmospheric pressure is below water's triplepoint and water ice sublimes into water vapor. Exceptions to this are the low-lying areas of the planet, most notablyin the Hellas Planitia impact basin, the largest such crater on Mars. It is so deep that the atmospheric pressure at thebottom reaches 1155 Pa, which is above the triple point, so if the temperature exceeded 0 C liquid water could

exist there.[citation needed]

Wind

The surface of Mars has a very low thermal inertia, which means it heatsquickly when the sun shines on it. Typical daily temperature swings, awayfrom the polar regions, are around 100 K. On Earth, winds often developin areas where thermal inertia changes suddenly, such as from sea to land.There are no seas on Mars, but there are areas where the thermal inertiaof the soil changes, leading to morning and evening winds akin to the sea

breezes on Earth.[24] The Antares project "Mars Small-Scale Weather"(MSW) has recently identified some minor weaknesses in current globalclimate models (GCMs) due to the GCMs' more primitive soil modeling"heat admission to the ground and back is quite important in Mars, so soil

schemes have to be quite accurate. "[25] Those weaknesses are beingcorrected and should lead to more accurate future assessments, but makecontinued reliance on older predictions of modeled Martian climatesomewhat problematic.

At low latitudes the Hadleycirculation dominates, and isessentially the same as the process which on Earth generates the tradewinds. At higher latitudes a series of high and low pressure areas, calledbaroclinic pressure waves, dominate the weather. Mars is dryer and colderthan Earth, and in consequence dust raised by these winds tends to remain inthe atmosphere longer than on Earth as there is no precipitation to wash it

out (excepting CO2 snowfall).[26] One such cyclonic storm was recently

captured by the Hubble space telescope (pictured below).

One of the major differences between Mars' and Earth's Hadley circulations

is their speed[27] which is measured on an overturning timescale. Theoverturning timescale on Mars is about 100 Martian days while on Earth, it isover a year.

EffecW of dXVW VWoUmV

See also: Martian soil#Atmospheric dust

When the Mariner 9 probe arrived at Mars in 1971, the world expected tosee crisp new pictures of surface detail. Instead they saw a near planet-wide

dust storm[28] with only the giant volcano Olympus Mons showing above thehaze. The storm lasted for a month, an occurrence scientists have since



2001 Hellas Basin dust storm

Time-lapse composite of Martian

horizon during Sols 1205 (0.94),

1220 (2.9), 1225 (4.1), 1233

(3.8), 1235 (4.7) shows how

much sunlight the July 2007 dust

storms blocked; Tau of 4.7

indicates 99% blocked.

DXVW SWoUm on MaUV.

November 18, 2012

November 25, 2012

Locations of Opportunity and

Curiosity rovers are noted (MRO).

learned is quite common on Mars.

As observed by the Viking spacecraft from the surface,[21] "during a globaldust storm the diurnal temperature range narrowed sharply, from fiftydegrees to only about ten degrees, and the wind speeds picked upconsiderably---indeed, within only an hour of the storm's arrival they hadincreased to 17 m/s (38 mph), with gusts up to 26 m/s (58 mph).Nevertheless, no actual transport of material was observed at either site,only a gradual brightening and loss of contrast of the surface material as dustsettled onto it." On June 26, 2001, the Hubble Space Telescope spotted adust storm brewing in Hellas Basin on Mars (pictured right). A day later thestorm "exploded" and became a global event. Orbital measurements showedthat this dust storm reduced the average temperature of the surface and

raised the temperature of the atmosphere of Mars by 30 C.[22] The lowdensity of the Martian atmospheremeans that winds of 18 to 22 m/s (40to 49 mph) are needed to lift dustfrom the surface, but since Mars is sodry, the dust can stay in theatmosphere far longer than on Earth,where it is soon washed out by rain.The season following that dust stormhad daytime temperatures 4 Cbelow average. This was attributed tothe global covering of light-coloreddust that settled out of the dust storm,temporarily increasing Mars'

albedo.[29]

In mid-2007 a planet-wide dust storm posed a serious threat to the solar-powered Spirit and Opportunity Mars Exploration Rovers by reducing theamount of energy provided by the solar panels and necessitating the shut-

down of most science experiments while waiting for the storms to clear.[30]

Following the dust storms, the rovers had significantly reduced power due to settling of dust on the arrays.

Dust storms are most common during perihelion, when the planet receives 40 percent more sunlight than duringaphelion. During aphelion water ice clouds form in the atmosphere, interacting with the dust particles and affecting

the temperature of the planet.[31]

It has been suggested that dust storms on Mars could play a role in storm formation similar to that of water clouds

on Earth.[ciWaWion needed] Observation since the 1950s has shown that the chances of a planet-wide dust storm in a

particular Martian year are approximately one in three.[32]

SalWaWion

The process of geological saltation is quite important on Mars as a mechanism for adding particulates to the

atmosphere. Saltating sand particles have been observed on the MER Spirit rover.[33] Theory and real world



HXEEOH YLHZ RI WKH FRORVVDO SRODU

FORXG RQ MDUV

MHWKDQH PDS

MHWKDQH RQ MDUV - "SRWHQWLDO VRXUFHV DQG VLQNV"

REVHUYDWLRQV KDYH QRW DJUHHG ZLWK HDFK RWKHU, FODVVLFDO WKHRU\ PLVVLQJ XS WR KDOI RI UHDO-ZRUOG VDOWDWLQJ SDUWLFOHV.[34]

A QHZ PRGHO PRUH FORVHO\ LQ DFFRUG ZLWK UHDO ZRUOG REVHUYDWLRQV GHPRQVWUDWHV WKDW VDOWDWLQJ SDUWLFOHV FUHDWH DQHOHFWULFDO ILHOG WKDW LQFUHDVHV WKH VDOWDWLRQ HIIHFW. MDUV JUDLQV VDOWDWH LQ 100 WLPHV KLJKHU DQG ORQJHU WUDMHFWRULHV DQG

UHDFK 5-10 WLPHV KLJKHU YHORFLWLHV WKDQ EDUWK JUDLQV GR.[35]

RepeaWing noUWheUn annXlaU cloXd

A ODUJH GRXJKQXW VKDSHG FORXG DSSHDUV LQ NRUWK SRODU UHJLRQ RI MDUV

DURXQG WKH VDPH WLPH HYHU\ MDUWLDQ \HDU DQG RI DERXW WKH VDPH VL]H.[36]

IW IRUPV LQ WKH PRUQLQJ, GLVVLSDWHV E\ WKH MDUWLDQ DIWHUQRRQ.[36] TKH RXWHUGLDPHWHU RI WKH FORXG LV URXJKO\ 1,600 NP (1,000 PL), DQG WKH LQQHU KROH

RU H\H LV 320 NP (200 PL) DFURVV.[37] TKH FORXG LV WKRXJKW WR EH

FRPSRVHG RI ZDWHU-LFH,[37] VR LW LV ZKLWH LQ FRORU, XQOLNH WKH PRUHFRPPRQ GXVW VWRUPV.

IW ORRNV OLNH D F\FORQLF VWRUP, VLPLODU WR KXUULFDQH, EXW LW GRHV QRW

URWDWH.[36] TKH FORXG DSSHDUV GXULQJ WKH QRUWKHUQ VXPPHU DQG DW KLJKODWLWXGH. SSHFXODWLRQ LV WKDW WKLV LV GXH WR XQLTXH FOLPDWH FRQGLWLRQV QHDU

WKH QRUWKHUQ SROH.[37] C\FORQH-OLNH VWRUPV ZHUH ILUVW GHWHFWHG GXULQJ WKH VLNLQJ RUELWDO PDSSLQJ SURJUDP, EXW WKH

QRUWKHUQ DQQXODU FORXG LV QHDUO\ WKUHH WLPHV ODUJHU.[37] TKH FORXG KDV DOVR EHHQ GHWHFWHG E\ YDULRXV SUREHV DQG

WHOHVFRSHV LQFOXGLQJ WKH HXEEOH DQG MDUV GOREDO SXUYH\RU.[36][37]

OWKHU UHSHDWLQJ HYHQWV DUH GXVW VWRUPV DQG GXVW GHYLOV.[37]

MeWhane pUeVence

See alVo: AWmoVpheUe of MaUV#MeWhane

AOWKRXJK PHWKDQH LV D JUHHQKRXVH JDV RQ EDUWK, WKH VPDOO DPRXQWV WKDWKDYH EHHQ FODLPHG WR EH SUHVHQW RQ MDUV ZRXOG KDYH OLWWOH HIIHFW RQ WKHMDUWLDQ JOREDO FOLPDWH. TUDFH DPRXQWV RI PHWKDQH (CH4) DW

FRQFHQWUDWLRQ RI VHYHUDO SDUWV SHU ELOOLRQ (SSE), ZHUH ILUVW UHSRUWHG LQ WKHDWPRVSKHUH RI MDUV E\ D WHDP DW WKH NASA GRGGDUG SSDFH FOLJKW

CHQWHU LQ 2003.[38][39]

IQ MDUFK 2004WKH MDUV E[SUHVV

OUELWHU[40][41][42][43] DQG JURXQG EDVHG REVHUYDWLRQV IURP

CDQDGD-FUDQFH-HDZDLL THOHVFRSH[44] DOVR VXJJHVWHG WKHSUHVHQFH RI PHWKDQH LQ WKH DWPRVSKHUH ZLWK D PROH IUDFWLRQ

RI DERXW 10 QPRO/PRO.[43] HRZHYHU, WKH FRPSOH[LW\ RI WKHVHREVHUYDWLRQV KDV VSDUNHG GLVFXVVLRQ DV WR WKH UHOLDELOLW\ RI

WKH UHVXOWV.[45]

SLQFH EUHDNXS RI WKDW PXFK PHWKDQH E\ XOWUDYLROHW OLJKWZRXOG RQO\ WDNH 350 \HDUV XQGHU FXUUHQW MDUWLDQ



(November 2, 2012).

Planet Mars volatile gases (Curiosity

rover, October 2012).

conditions, if methane is present some sort of active source

must be replenishing the gas.[46] Clathrate hydrates,[47] or

water-rock reactions [48] could be possible geological sources of methane but there is presently no consensus onthe source or existence of Martian methane.

The Curiosity rover landed on Mars in August 2012. It is able to make precise abundance measurements and also

distinguish between different isotopologues of methane.[49] The first measurements with the Tunable Laser

Spectrometer (TLS) indicate that there is less than 5 ppb of methane at the landing site.[50][51][52][53] OnSeptember 19, 2013 NASA scientists used further measurements from Curiosity to report a non-detection ofatmospheric methane with a measured value of 0.18 0.67 ppbv corresponding to an upper limit of 1.3 ppbv

(95% confidence limit).[54]

The Indian Mars Orbiter Mission, launched in 5 November 2013, will attempt to detect and map the sources of

methane, if they exist.[55] The ExoMars Trace Gas Orbiter planned to launch in 2016 would further study the

methane,[56][57] as well as its decomposition products such as formaldehyde and methanol.

Carbon dio[ide carving

Mars Reconnaissance Orbiter images suggest an unusual erosion effect occurs based on Mars' unique climate.Spring warming in certain areas leads to CO2 ice subliming and flowing upwards, creating highly unusual erosion

patterns called "spider gullies".[58] Translucent CO2 ice forms over winter and as the spring sunlight warms the

surface, it vaporizes the CO2 to gas which flows uphill under the translucent CO2 ice. Weak points in that ice lead

to CO2 geysers.[58]

Mountains

Martian storms are significantly affected by Mars' large mountain

ranges.[59] Individual mountains like record holding Olympus Mons(27 km (17 mi)) can affect local weather but larger weather effectsare due to the larger collection of volcanoes in the Tharsis region.

One unique repeated weather phenomena involving Mountains is aspiral dust cloud that forms over Arsia Mons. The spiral dust cloudover Arsia Mons can tower 15 to 30 km (9.3 to 18.6 mi) above the

volcano.[60] Clouds are present around Arsia Mons throughout the

Martian year, peaking in late summer.[61]

Clouds surrounding mountains display a seasonal variability. Cloudsat Olympus Mons and Ascreaus Mons appear in northernhemisphere spring and summer, reaching a total maximum area of

approximately 900,000 km2 and 1,000,000 km2 respectively in latespring. Clouds around Alba Patera and Pavonis Mons show an

additional, smaller peak in late summer. Very few clouds were observed in winter. Predictions from the Mars

General Circulation Model are consistent with these observations.[61]

Polar caps



AQ iOOXVWUaWiRQ Rf ZhaW MaUV PighW

haYe ORRNed OiNe dXUiQg aQ ice age

beWZeeQ 2.1 PiOOiRQ aQd 400,000

\eaUV agR, ZheQ MaUV'V a[iaO WiOW iV

beOieYed WR haYe beeQ PXch OaUgeU

WhaQ WRda\.

HiRISE iPage Rf "daUN dXQe

VSRWV" aQd faQV fRUPed b\

eUXSWiRQV Rf CO2 gaV ge\VeUV RQ

MaUV' VRXWh SROaU ice VheeW.

MaUV haV ice caSV aW iWV QRUWh SROe aQd VRXWh SROe, Zhich PaiQO\ cRQViVW Rf ZaWeU ice; hRZeYeU, WheUe iV fUR]eQcaUbRQ diR[ide (dU\ ice) SUeVeQW RQ WheiU VXUfaceV. DU\ ice accXPXOaWeV iQ WheQRUWh SROaU UegiRQ (POaQXP BRUeXP) iQ ZiQWeU RQO\, VXbOiPiQg cRPSOeWeO\ iQVXPPeU, ZhiOe Whe VRXWh SROaU UegiRQ addiWiRQaOO\ haV a SeUPaQeQW dU\ ice

cRYeU XS WR eighW PeWeUV (25 feeW) WhicN.[62] ThiV diffeUeQce iV dXe WR WhehigheU eOeYaWiRQ Rf Whe VRXWh SROe.

SR PXch Rf Whe aWPRVSheUe caQ cRQdeQVe aW Whe ZiQWeU SROe WhaW WheaWPRVSheUic SUeVVXUe caQ YaU\ b\ XS WR a WhiUd Rf iWV PeaQ YaOXe. ThiVcRQdeQVaWiRQ aQd eYaSRUaWiRQ ZiOO caXVe Whe SURSRUWiRQ Rf Whe

QRQcRQdeQVabOe gaVeV iQ Whe aWPRVSheUe WR chaQge iQYeUVeO\.[26] TheecceQWUiciW\ Rf MaUV'V RUbiW affecWV WhiV c\cOe, aV ZeOO aV RWheU facWRUV. IQ WheVSUiQg aQd aXWXPQ ZiQd dXe WR Whe caUbRQ diR[ide VXbOiPaWiRQ SURceVV iV VR

VWURQg WhaW iW caQ be a caXVe Rf Whe gORbaO dXVW VWRUPV PeQWiRQed abRYe.[63]

The QRUWheUQ SROaU caS haV a diaPeWeU Rf aSSUR[iPaWeO\ 1,000 NP dXUiQg Whe

QRUWheUQ MaUV VXPPeU,[64] aQd cRQWaiQV abRXW 1.6 PiOOiRQ cXbic NiORPeWUeV

Rf ice, Zhich if VSUead eYeQO\ RQ Whe caS ZRXOd be 2 NP WhicN.[65] (ThiVcRPSaUeV WR a YROXPe Rf 2.85 PiOOiRQ cXbic NiORPeWUeV fRU Whe GUeeQOaQd iceVheeW.) The VRXWheUQ SROaU caS haV a diaPeWeU Rf 350 NP aQd a Pa[iPXP

WhicNQeVV Rf 3 NP.[66] BRWh SROaU caSV VhRZ VSiUaO WURXghV, Zhich ZeUefRUPeUO\ beOieYed WR fRUP aV a UeVXOW Rf diffeUeQWiaO VROaU heaWiQg, cRXSOed

ZiWh Whe VXbOiPaWiRQ Rf ice aQd cRQdeQVaWiRQ Rf ZaWeU YaSRU.[67][68] ReceQWaQaO\ViV Rf ice SeQeWUaWiQg UadaU daWa fURP SHARAD haV dePRQVWUaWed WhaWWhe VSiUaO WURXghV aUe fRUPed fURP a XQiTXe ViWXaWiRQ iQ Zhich high deQViW\NaWabaWic ZiQdV deVceQd fURP Whe SROaU high WR WUaQVSRUW ice aQd cUeaWe OaUge

ZaYeOeQgWh bedfRUPV.[69][70] The VSiUaO VhaSe cRPeV fURP CRUiROiV effecWfRUciQg Rf Whe ZiQdV, PXch OiNe ZiQdV RQ eaUWh VSiUaO WR fRUP a hXUUicaQe. TheWURXghV did QRW fRUP ZiWh eiWheU ice caS, iQVWead Whe\ begaQ WR fRUP beWZeeQ2.4 PiOOiRQ aQd 500,000 \eaUV agR, afWeU WhUee fRXUWhV Rf Whe ice caS ZaV iQSOace. ThiV VXggeVWV WhaW a cOiPaWic VhifW aOORZed fRU WheiU RQVeW. BRWh SROaUcaSV VhUiQN aQd UegURZ fROORZiQg Whe WePSeUaWXUe fOXcWXaWiRQ Rf Whe MaUWiaQVeaVRQV; WheUe aUe aOVR ORQgeU-WeUP WUeQdV WhaW aUe QRW fXOO\ XQdeUVWRRd.

DXUiQg Whe VRXWheUQ hePiVSheUe VSUiQg, VROaU heaWiQg Rf dU\ ice deSRViWV aW Whe VRXWh SROe OeadV iQ SOaceV WRaccXPXOaWiRQ Rf SUeVVXUi]ed CO2 gaV beORZ Whe VXUface Rf Whe VePiWUaQVSaUeQW ice, ZaUPed b\ abVRUSWiRQ Rf

UadiaWiRQ b\ Whe daUNeU VXbVWUaWe. AfWeU aWWaiQiQg Whe QeceVVaU\ SUeVVXUe, Whe gaV bXUVWV WhURXgh Whe ice iQ ge\VeU-OiNeSOXPeV. WhiOe Whe eUXSWiRQV haYe QRW beeQ diUecWO\ RbVeUYed, Whe\ OeaYe eYideQce iQ Whe fRUP Rf "daUN dXQe VSRWV"aQd OighWeU faQV aWRS Whe ice, UeSUeVeQWiQg VaQd aQd dXVW caUUied aORfW b\ Whe eUXSWiRQV, aQd a VSideU-OiNe SaWWeUQ Rf

gURRYeV cUeaWed beORZ Whe ice b\ Whe RXWUXVhiQg gaV.[71][72] (Vee Ge\VeUV RQ MaUV.) EUXSWiRQV Rf QiWURgeQ gaVRbVeUYed b\ Vo\ager 2 RQ TUiWRQ aUe WhRXghW WR RccXU b\ a ViPiOaU PechaQiVP.

Solar Zind

MaUV ORVW PRVW Rf iWV PagQeWic fieOd abRXW fRXU biOOiRQ \eaUV agR. AV a UeVXOW, VROaU ZiQd aQd cRVPic UadiaWiRQiQWeUacWV diUecWO\ ZiWh Whe MaUWiaQ iRQRVSheUe. ThiV NeeSV Whe aWPRVSheUe WhiQQeU WhaQ iW ZRXOd RWheUZiVe be b\

VROaU ZiQd acWiRQ cRQVWaQWO\ VWUiSSiQg aZa\ aWRPV fURP Whe RXWeU aWPRVSheUic Oa\eU.[73] MRVW Rf Whe hiVWRUicaO



In spring, sublimation of ice causes

sand from below the ice layer to form

fan-shaped deposits on top of the

seasonal ice.

atmospheric loss on Mars can be traced back to this solar wind effect. Current theory posits a weakening solarwind and thus today's atmosphere stripping effects are much less than those in the past when the solar wind was

stronger.[citation needed]

Seasons

See also: Astronom\ on Mars#Seasons

Mars has an axial tilt of 25.2. This means that there are seasons onMars, just as on Earth. The eccentricity of Mars' orbit is 0.1, muchgreater than the Earth's present orbital eccentricity of about 0.02. Thelarge eccentricity causes the insolation on Mars to vary as the planetorbits the Sun (the Martian year lasts 687 days, roughly 2 Earth years).As on Earth, Mars' obliquity dominates the seasons but, because of thelarge eccentricity, winters in the southern hemisphere are long and coldwhile those in the North are short and warm.

It is now widely believed that ice accumulated when Mars' orbital tilt wasvery different from what it is now (the axis the planet spins on has

considerable "wobble," meaning its angle changes over time).[74][75][76] Afew million years ago, the tilt of the axis of Mars was 45 degrees insteadof its present 25 degrees. Its tilt, also called obliquity, varies greatlybecause its two tiny moons cannot stabilize it like our moon.

Many features on Mars, especially in the Ismenius Lacus quadrangle, are believed to contain large amounts of ice.The most popular model for the origin of the ice is climate change from large changes in the tilt of the planet's

rotational axis. At times the tilt has even been greater than 80 degrees[77][78] Large changes in the tilt explains manyice-rich features on Mars.

Studies have shown that when the tilt of Mars reaches 45 degrees from its current 25 degrees, ice is no longer

stable at the poles.[79] Furthermore, at this high tilt, stores of solid carbon dioxide (dry ice) sublimate, therebyincreasing the atmospheric pressure. This increased pressure allows more dust to be held in the atmosphere.Moisture in the atmosphere will fall as snow or as ice frozen onto dust grains. Calculations suggest this material will

concentrate in the mid-latitudes.[80][81] General circulation models of the Martian atmosphere predict accumulations

of ice-rich dust in the same areas where ice-rich features are found.[82] When the tilt begins to return to lower

values, the ice sublimates (turns directly to a gas) and leaves behind a lag of dust.[83][83][84] The lag deposit caps

the underlying material so with each cycle of high tilt levels, some ice-rich mantle remains behind.[85] Note, that thesmooth surface mantle layer probably represents only relative recent material.

The seasons present unequal lengths are as follows:

SeasonSols

(on Mars)Da\s

(on Earth)

Northern Spring, Southern Autumn: 193.30 92.764

Northern Summer, Southern Winter: 178.64 93.647



Pits in south polar ice cap, MGS 1999, NASA

Northern Autumn, Southern Spring: 142.70 89.836Northern Winter, Southern Summer: 153.95 88.997

Precession in the alignment of the obliquity and eccentricity lead to global warming and cooling ('great' summers and

winters) with a period of 170,000 years.[86]

Like Earth, the obliquity of Mars undergoes periodic changes which can lead to long-lasting changes in climate.Once again, the effect is more pronounced on Mars because it lacks the stabilizing influence of a large moon. As aresult the obliquity can alter by as much as 45. Jacques Laskar, of France's National Centre for ScientificResearch, argues that the effects of these periodic climate changes can be seen in the layered nature of the ice cap

at the Martian north pole.[87] Current research suggests that Mars is in a warm interglacial period which has lasted

more than 100,000 years.[88]

Because the Mars Global Surveyor was able to observe Mars for 4 Martian years, it was found that Martianweather was similar from year to year. Any differences were directly related to changes in the solar energy thatreached Mars. Scientists were even able to accurately predict dust storms that would occur during the landing of

Beagle 2. Regional dust storms were discovered to be closely related to where dust was available.[89]

EYidence foU UecenW climaWic change

There have been changes around the south pole(Planum Australe) over the past few Martianyears. In 1999 the Mars Global Surveyorphotographed pits in the layer of frozen carbondioxide at the Martian south pole. Because oftheir striking shape and orientation these pitshave become known as swiss cheese features.In 2001 the craft photographed the same pitsagain and found that they had grown larger,retreating about 3 meters in one Martian

year.[90] These features are caused by thesublimation of the dry ice layer, therebyexposing the inert water ice layer. More recent

observations indicate that the ice at Mars' south pole is continuing to sublime.[91] The pits in the ice continue togrow by about 3 meters per Martian year. Malin states that conditions on Mars are not currently conducive to the

formation of new ice. A NASA press release has suggested that this indicates a "climate change in progress"[92] onMars. In a summary of observations with the Mars Orbiter Camera, researchers speculated that some dry ice mayhave been deposited between the Mariner 9 and the Mars Global Surveyor mission. Based on the current rate of

loss, the deposits of today may be gone in a hundred years.[89]

Elsewhere on the planet, low latitude areas have more water ice than they should have given current climatic

conditions.[93] Mars Odyssey "is giving us indications of recent global climate change in Mars," said Jeffrey Plaut,project scientist for the mission at NASA's Jet Propulsion Laboratory, in non-peer reviewed published work in2003.

AWWUibXWion WheoUieV



Mars Global Climate Zones, based on

temperature, modified by topography,

albedo, actual solar radiation.

Polar changes

Colaprete et al. conducted simulations with the Mars General Circulation Model which show that the local climatearound the Martian south pole may currently be in an unstable period. The simulated instability is rooted in thegeography of the region, leading the authors to speculate that the sublimation of the polar ice is a local phenomenon

rather than a global one.[94] The researchers showed that even with a constant solar luminosity the poles werecapable of jumping between states of depositing or losing ice. The trigger for a change of states could be either

increased dust loading in the atmosphere or an albedo change due to deposition of water ice on the polar cap.[95]

This theory is somewhat problematic due to the lack of ice depositation after the 2001 global dust storm.[96]

Another issue is that the accuracy of the Mars General Circulation Model decreases as the scale of thephenomenon becomes more local.

It has been argued that "observed regional changes in south polar ice cover are almost certainly due to a regional

climate transition, not a global phenomenon, and are demonstrably unrelated to external forcing."[86] Writing in aNaWXre news story, Chief News and Features Editor Oliver Morton said "The warming of other solar bodies hasbeen seized upon by climate sceptics. On Mars, the warming seems to be down to dust blowing around and

uncovering big patches of black basaltic rock that heat up in the day."[97][98]

Solar irradiance

Despite the absence of a time series for Martian global temperatures, K. I. Abdusamatov has proposed that"parallel global warmings" observed simultaneously on Mars and on Earth can only be a consequence of the same

factor: a long-time change in solar irradiance."[99] While some individuals who reject the science of global warming

take this as proof that humans are not causing climate change,[100] Abdusamatov's hypothesis has not beenaccepted by the scientific community. His assertions have not been published in the peer-reviewed literature, andhave been dismissed by other scientists, who have stated that "the idea just isn't supported by the theory or by the

observations" and that it "doesn't make physical sense."[101] Other scientists have proposed that the observed

variations are caused by irregularities in the orbit of Mars or a possible combination of solar and orbital effects.[102]

Climate ]ones

Terrestrial Climate zones first have been defined by Wladimir K|ppenbased on the distribution of vegetation groups. Climate classification isfurthermore based on temperature, rainfall, and subdivided based upondifferences in the seasonal distribution of temperature and precipitation;and a separate group exists for extrazonal climates like in high altitudes.Mars has neither vegetation nor rainfall, so any climate classification couldbe only based upon temperature; a further refinement of the system maybe based on dust distribution, water vapor content, occurrence of snow.

Solar Climate Zones can also be easily defined for Mars.[103]

Current missions

The 2001 Mars Odyssey is currently orbiting Mars and taking global atmospheric temperature measurements withthe TES instrument. The Mars Reconnaissance Orbiter is currently taking daily weather and climate relatedobservations from orbit. One of its instruments, the Mars climate sounder is specialized for climate observation



TempeUaWXUe PUeVVXUe

HXmidiW\

ZoUk. The MSL ZaV laXnched in NoYembeU 2011 and landed on MaUV on AXgXVW 6, 2012.[104]

Curiosity rover Temperature, Pressure, Humidity at Gale Crater on Mars (August 2012 February2013).

Future missions

MaUV OUbiWeU MiVVion - en roXWe, laXnched on 5 NoYembeU 2013MAVEN - en roXWe, laXnched on 18 NoYembeU 2013

E[oMaUV TUace GaV OUbiWeU Wo laXnch in 2016

See also

AWmoVpheUe of MaUV

E[ploUaWion of MaUVGeolog\ of MaUVMaUV analog habiWaW

MaUV ClimaWe OUbiWeUMeWNeW, a pUopoVed meWeoUological neWZoUk on MaUV

PlanXm AXVWUale, Whe VoXWheUn polaU plainPlanXm BoUeXm, Whe noUWheUn polaU plain

WaWeU on MaUV



RefeUenceV

1. ^ Francis Reddy (23 September 2005). "MGS sees changing face of Mars"(http://www.astronomy.com/asy/default.aspx?c=a&id=3503). Astronomy Magazine. Retrieved 2007-09-06.

2. ^ NASA. "Mars General Circulation Modeling" (http://www-mgcm.arc.nasa.gov/MGCM.html). NASA. Retrieved2007-02-22.

3. ^D E Exploring Mars in the 1700s (http://www.exploringmars.com/history/1700.html)

4. ^ Exploring Mars in the 1800s (http://www.exploringmars.com/history/1800.html)

5. ^ "Clay studies might alter Mars theories"(http://web.archive.org/web/20070930201205/http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070719-14530900-bc-us-mars.xml). Science Daily. 19 July 2007. Archived fromthe original (http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20070719-14530900-bc-us-mars.xml) on September 30, 2007. Retrieved 2007-09-06.

6. ^ Carr, M.H., et al. (1977), Martian impact craters and emplacement of ejecta by surface flow, J. Geophys. Res.,82, 4055-65.

7. ^ Golombek, M.P., and Bridges, N.T. (2000), Erosion rates on Mars and implications for climate change:constraints from the Pathfinder landing site, J. Geophys. Res., 105(E1), 18411853

8. ^ Craddock, R.A., and Howard, A.D. (2002), The case for rainfall on a warm, wet early Mars, J. Geophys. Res.,107(E11), doi:10.1029/2001JE001505 (http://dx.doi.org/10.1029%2F2001JE001505)

9. ^ Shuster, David L.; Weiss, Benjamin P. (July 22, 2005). "Martian Surface Paleotemperatures from

Thermochronology of Meteorites". Science 309 (5734): 594600. Bibcode:2005Sci...309..594S(http://adsabs.harvard.edu/abs/2005Sci...309..594S). doi:10.1126/science.1113077(http://dx.doi.org/10.1126%2Fscience.1113077). PMID 16040703 (//www.ncbi.nlm.nih.gov/pubmed/16040703).

10. ^ Hartmann, W. 2003. A Traveler's Guide to Mars. Workman Publishing. NY NY.

11. ^ aberle, R.M. (1998), Early Climate Models, J. Geophys. Res., 103(E12),28467-79

12. ^ "Weather at the Mars Exploration Rover and Beagle 2 Landing Sites"(http://www.msss.com/mars_images/moc/mer_weather/). Malin Space Science Systems. Retrieved 2007-09-08.

13. ^ "NASA Mars Lander Sees Falling Snow, Soil Data Suggest Liquid Past"(http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080929.html). 2008-09-29. Retrieved 2008-10-03.

14. ^ Mars Clouds Higher Than Any On Earth (http://www.space.com/scienceastronomy/060828_mars_clouds.html)

15. ^ Eydelman, Albert (2001). "Temperature on the Surface of Mars"(http://hypertextbook.com/facts/2001/AlbertEydelman.shtml). The Ph\sics Factbook.

16. ^ "Focus Sections :: The Planet Mars" (http://www.marsnews.com/focus/mars/). MarsNews.com. Retrieved2007-09-08.

17. ^ "Mars Facts" (http://quest.nasa.gov/aero/planetary/mars.html). NASA. Retrieved 2013-06-20.

18. ^ James E. Tillman Mars Temperature Overview (http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/temperature_overview.html)

19. ^ Extreme Planet Takes its Toll (http://marsrover.nasa.gov/spotlight/20070612.html) Jet Propulsion Laborator\Featured Stor\, 12th June 2007.

20. ^ Liu, Junjun; Mark I. Richardson, and R. J. Wilson (15 August 2003). "An assessment of the global, seasonal,and interannual spacecraft record of Martian climate in the thermal infrared"

(http://www.gfdl.gov/~gth/netscape/2003/liu0301.pdf) ( Scholar search (http://scholar.google.co.uk/scholar?

hl=en&lr=&q=author%3ALiu+intitle%3AAn+assessment+of+the+global%2C+seasonal%2C+and+interannual+spacecraft+record+of+

Martian+climate+in+the+thermal+infrared&as_publication=%5B%5BJournal+of+Geophysical+Research%5D%5D&as_ylo=&as_yhi

=&btnG=Search)). Journal of Geoph\sical Research 108 (5089): 5089. Bibcode:2003JGRE..108.5089L(http://adsabs.harvard.edu/abs/2003JGRE..108.5089L). doi:10.1029/2002JE001921(http://dx.doi.org/10.1029%2F2002JE001921). Retrieved 2007-09-08. Template:Toter Link

21. ^D E William Sheehan, The Planet Mars: A Histor\ of Observation and Discover\, Chapter 13 (available on theweb (http://www.uapress.arizona.edu/onlinebks/mars/chap13.htm))

^D E Mark A. Gurwell, Edwin A. Bergin, Gary J. Melnick and Volker Tolls, "Mars surface and atmospheric



22. ^D E Mark A. Gurwell, Edwin A. Bergin, Gary J. Melnick and Volker Tolls, "Mars surface and atmospherictemperature during the 2001 global dust storm," IcaUXV, VolXme 175, IVVXe 1, Ma\ 2005, PageV 23-3,doi:10.1016/j.icaUXV.2004.10.009 (hWWp://d[.doi.oUg/10.1016%2Fj.icaUXV.2004.10.009)

23. A Mars General Circulation Modeling Group. "Mars' low surface pressure. .." (http://www-mgcm.arc.nasa.gov/mgcm/HTML/WEATHER/pressure.html). NASA. Retrieved 2007-02-22.

24. A Mars General Circulation Modeling Group. "Mars' desert surface..." (http://www-mgcm.arc.nasa.gov/mgcm/HTML/WEATHER/surface.html). NASA. Retrieved 2007-02-25.

25. A Antares project "Mars Small-Scale Weather" (MSW)(http://websrv2.tekes.fi/opencms/opencms/OhjelmaPortaali/Paattyneet/Antares/en/Dokumenttiarkisto/Viestinta_ja_aktivointi/Lehdistotiedotteet/Press/fallpress2003.htx.i1948.doc)

26. ^D E Franois Forget. "Alien Weather at the Poles of Mars" (http://www-mars.lmd.jussieu.fr/mars/publi/forget_science2004.pdf). Science. Retrieved 2007-02-25.

27. A Mars General Circulation Modeling Group. "The Martian tropics..." (http://www-mgcm.arc.nasa.gov/mgcm/HTML/WEATHER/tropics.html). NASA. Retrieved 2007-09-08.

28. A NASA. "Planet Gobbling Dust Storms" (http://science.nasa.gov/headlines/y2001/ast16jul_1.htm). NASA.Retrieved 2007-02-22.

29. A Global warming and climate forcing by recent albedo changes on Mars(http://humbabe.arc.nasa.gov/~fenton/pdf/fenton/nature05718.pdf)

30. A Mars Exploration Rover Status Report Concern Increasing About Opportunity(http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20070731a.html)

31. A "Duststorms on Mars" (http://www.whfreeman.com/ENVIRONMENTALGEOLOGY/EXMOD36/F3614.HTM).whfreeman.com. Retrieved 2007-02-22.

32. A Zurek, Richard W.; Leonard J. Martin (1993). "Interannual variability of planet-encircling dust storms on Mars"(http://www.agu.org/pubs/crossref/1993/92JE02936.shtml). JoXUnal of Geoph\Vical ReVeaUch (Journal of

Geophysical Research) 98 (E2): 32473259. Bibcode:1993JGR....98.3247Z(http://adsabs.harvard.edu/abs/1993JGR....98.3247Z). doi:10.1029/92JE02936(http://dx.doi.org/10.1029%2F92JE02936). Retrieved 2007-03-16.

33. A G. Landis, et al., "Dust and Sand Deposition on the MER Solar Arrays as Viewed by the Microscopic Imager,"37th Lunar and Planetary Science Conference, Houston TX, March 1317, 2006. pdf file(http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1932.pdf) (also summarized in NASA Glenn Research andTechnology 2006 (http://www.grc.nasa.gov/WWW/RT/2006/RP/RPV-landis2.html) report

34. A Kok, Jasper F.; Renno, Nilton O. (2008). "Electrostatics in Wind-Blown Sand". Ph\Vical ReYieZ LeWWeUV 100 (1):014501. arXiv:0711.1341 (//arxiv.org/abs/0711.1341). Bibcode:2008PhRvL.100a4501K(http://adsabs.harvard.edu/abs/2008PhRvL.100a4501K). doi:10.1103/PhysRevLett.100.014501(http://dx.doi.org/10.1103%2FPhysRevLett.100.014501). PMID 18232774(//www.ncbi.nlm.nih.gov/pubmed/18232774).

35. A Almeida, Murilo P. et al. (2008). "Giant saltation on Mars" (//www.ncbi.nlm.nih.gov/pmc/articles/PMC2359785).

PNAS 105 (17): 62226226. Bibcode:2008PNAS..105.6222A(http://adsabs.harvard.edu/abs/2008PNAS..105.6222A). doi:10.1073/pnas.0800202105(http://dx.doi.org/10.1073%2Fpnas.0800202105). PMC 2359785(//www.ncbi.nlm.nih.gov/pmc/articles/PMC2359785). PMID 18443302(//www.ncbi.nlm.nih.gov/pubmed/18443302).

36. ^D E F G Mars Global Surveyor - "8 Year Anniversary" (http://mpfwww.jpl.nasa.gov/mgs/gallery/20050912-repeatNPWIC.html)

37. ^D E F G H I David Brand and Ray Villard (19 May 1999). "Colossal cyclone swirling near Martian north pole isobserved by Cornell-led team on Hubble telescope"(http://www.news.cornell.edu/releases/May99/mars.cyclone.deb.html). Cornell News. Retrieved 2007-09-06.

38. A Mumma, M. J.; Novak, R. E.; DiSanti, M. A.; Bonev, B. P., "A Sensitive Search for Methane on Mars"(http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2003DPS....35.1418M&db_key=AST&data_type=HTML&format=) (abstract only). AmericanAstronomical Society, DPS meeting #35, #14.18.



39. A Michael J. Mumma. "Mars Methane Boosts Chances for Life" (http://www-mgcm.arc.nasa.gov/MGCM.html).Skytonight.com. Archived (http://web.archive.org/web/20070220100252/http://www-mgcm.arc.nasa.gov/MGCM.html) from the original on 20 February 2007. Retrieved February 23, 2007.

40. A V. Formisano, S. Atreya T. Encrenaz, N. Ignatiev, M. Giuranna (2004). "Detection of Methane in the

Atmosphere of Mars". Science 306 (5702): 17581761. Bibcode:2004Sci...306.1758F(http://adsabs.harvard.edu/abs/2004Sci...306.1758F). doi:10.1126/science.1101732(http://dx.doi.org/10.1126%2Fscience.1101732). PMID 15514118 (//www.ncbi.nlm.nih.gov/pubmed/15514118).

41. A Francis Reddy (7 March 2006). "Titan, Mars methane may be on ice"(http://www.astronomy.com/asy/default.aspx?c=a&id=4009). Astronomy Magazine. Retrieved 2007-09-06.

42. A V. Formisano, S. Atreya, T. Encrenaz, N. Ignatiev, M. Giuranna (2004). "Detection of Methane in the

Atmosphere of Mars". Science 306 (5702): 17581761. Bibcode:2004Sci...306.1758F(http://adsabs.harvard.edu/abs/2004Sci...306.1758F). doi:10.1126/science.1101732(http://dx.doi.org/10.1126%2Fscience.1101732). PMID 15514118 (//www.ncbi.nlm.nih.gov/pubmed/15514118).

43. ^D E "Mars Express confirms methane in the Martian atmosphere"(http://www.esa.int/SPECIALS/Mars_Express/SEMZ0B57ESD_0.html). ESA. March 30, 2004. Retrieved 2008-08-19.

44. A V. A. Krasnopolskya, J. P. Maillard, T. C. Owen (2004). "Detection of methane in the Martian atmosphere:

evidence for life?". Icarus 172 (2): 537547. Bibcode:2004Icar..172..537K(http://adsabs.harvard.edu/abs/2004Icar..172..537K). doi:10.1016/j.icarus.2004.07.004(http://dx.doi.org/10.1016%2Fj.icarus.2004.07.004).

45. A Zahnle, Kevin; Freedman, Richard S.; Catling, David C., [1] (http://adsabs.harvard.edu/abs/2011Icar..212..493Z)(abstract only). Icarus, Volume 212, Issue 2, p. 493-503.

46. A Martin Baucom (2006). "Life on Mars?"(http://web.archive.org/web/20060223045353/http://www.americanscientist.org/template/AssetDetail/assetid/49613

). American Scientist 94 (2). Archived from the original(http://www.americanscientist.org/template/AssetDetail/assetid/49613) on February 23, 2006. Retrieved 2007-02-26.

47. A Thomas, Caroline; et al. (January 2009). "Variability of the methane trapping in Martian subsurface clathratehydrates" (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6T-4TPHRT5-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1

&_urlVersion=0&_userid=10&md5=e64bf861e4ef71f5336823d5dc1b9e12). Planetar\ and Space Science 57 (1):4247. arXiv:0810.4359 (//arxiv.org/abs/0810.4359). Bibcode:2009P&SS...57...42T(http://adsabs.harvard.edu/abs/2009P&SS...57...42T). doi:10.1016/j.pss.2008.10.003(http://dx.doi.org/10.1016%2Fj.pss.2008.10.003). Retrieved August 2, 2009.

48. A Tazaz, Amanda M.; Bebout, Brad M.; Kelley, Cheryl A.; Poole, Jennifer; Chanton, Jeffrey P. [2](http://adsabs.harvard.edu/abs/2013Icar..224..268T) (abstract only). Icarus, Volume 224, Issue 2, p. 268-275.

49. A Tenenbaum, David (June 9, 2008):). "Making Sense of Mars Methane"(http://www.astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2765&mode=thread&order=0&thold=0). Astrobiolog\ Maga]ine.Archived (http://web.archive.org/web/20080923195833/http://astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2765&mode=thread&order=0&thold=0) from the original on 23September 2008. Retrieved October 8, 2008.

50. A "Mars Curiosity Rover News Telecon -November 2, 2012" (http://www.ustream.tv/nasajpl).

51. A Kerr, Richard A. (November 2, 2012). "Curiosity Finds Methane on Mars, or Not"(http://news.sciencemag.org/sciencenow/2012/11/curiosity-finds-methane-on-mars-.html). Science (journal).Retrieved November 3, 2012.

52. A Wall, Mike (November 2, 2012). "Curiosity Rover Finds No Methane on Mars Yet"(http://www.space.com/18333-mars-rover-curiosity-methane-measurements.html). Space.com. RetrievedNovember 3, 2012.

53. A Chang, Kenneth (November 2, 2012). "Hope of Methane on Mars Fades"(http://www.nytimes.com/2012/11/03/science/space/hopes-for-methane-on-mars-deflated.html). New YorkTimes. Retrieved November 3, 2012.



54. A Webster, Christopher R.; Mahaffy, Paul R.; Atreya, Sushil K.; Flesch, Gregory J.; Farley, Kenneth A.(September 19, 2013). "Low Upper Limit to Methane Abundance on Mars"(http://www.sciencemag.org/content/early/2013/09/18/science.1242902.abstract). Science.doi:10.1126/science.1242902 (http://dx.doi.org/10.1126%2Fscience.1242902). Retrieved September 19, 2013.

55. A Staff (September 2012). "Mangalyaan -Mission Objectives" (http://www.isro.org/pslv-c25/mission-objective.aspx). Indian Space Science Data Centre. Retrieved 8 October 2013.

56. A Rincon, Paul (July 9, 2009). "Agencies outline Mars initiative"(http://news.bbc.co.uk/2/hi/science/nature/8130393.stm). BBC News. Retrieved July 26, 2009.

57. A "NASA orbiter to hunt for source of Martian methane in 2016"(http://www.thaindian.com/newsportal/health/nasa-orbiter-to-hunt-for-source-of-martian-methane-in-2016_100163335.html). Thaindian News. March 6, 2009. Retrieved July 26, 2009.

58. ^D E Chang, Kenneth (2007-12-12). "Mars Rover Finding Suggests Once Habitable Environment"(http://www.nytimes.com/2007/12/12/science/space/12mars.html?ex=1355202000&en=c42725b421422007&ei=5124&partner=permalink&exprod=permalink). The New York Times.Retrieved 2010-04-30.

59. A Mars General Circulation Modeling Group. "The Martian mountain ranges..." (http://www-mgcm.arc.nasa.gov/mgcm/HTML/WEATHER/mountains.html). NASA. Retrieved 2007-09-08.

60. A "PIA04294: Repeated Clouds over Arsia Mons" (http://photojournal.jpl.nasa.gov/catalog/PIA04294). NASA.Retrieved 2007-09-08.

61. ^D E Benson et al. (2006). "Interannual variability of water ice clouds over major martian volcanoes observed by

MOC". Icarus 184 (2): 365371. Bibcode:2006Icar..184..365B(http://adsabs.harvard.edu/abs/2006Icar..184..365B). doi:10.1016/j.icarus.2006.03.014(http://dx.doi.org/10.1016%2Fj.icarus.2006.03.014).

62. A Darling, David. "Mars, polar caps, ENCYCLOPEDIA OF ASTROBIOLOGY, ASTRONOMY, ANDSPACEFLIGHT" (http://www.daviddarling.info/encyclopedia/M/Marspoles.html). Retrieved 2007-02-26.

63. A Mars General Circulation Modeling Group. "Mars' dry ice polar caps..." (http://www-mgcm.arc.nasa.gov/mgcm/HTML/WEATHER/ice.html). NASA. Retrieved 2007-02-22.

64. A "MIRA's Field Trips to the Stars Internet Education Program"(http://www.mira.org/fts0/planets/097/text/txt002x.htm). Mira.org. Retrieved 2007-02-26.

65. A Carr, Michael H. (2003). "Oceans on Mars: An assessment of the observational evidence and possible fate".

Journal of Geoph\sical Research (PDF) 108 (5042): 24. Bibcode:2003JGRE..108.5042C(http://adsabs.harvard.edu/abs/2003JGRE..108.5042C). doi:10.1029/2002JE001963(http://dx.doi.org/10.1029%2F2002JE001963).

66. A Phillips, Tony. "Mars is Melting, Science at NASA"(http://science.nasa.gov/headlines/y2003/07aug_southpole.htm). Retrieved 2007-02-26.

67. A Pelletier, J. D. (2004). "How do spiral troughs form on Mars?" (http://www.gsajournals.org/perlserv/?

request=get-abstract&doi=10.1130%2FG20228.2). Geolog\ 32 (4): 365367. Bibcode:2004Geo....32..365P(http://adsabs.harvard.edu/abs/2004Geo....32..365P). doi:10.1130/G20228.2(http://dx.doi.org/10.1130%2FG20228.2). Retrieved 2007-02-27.

68. A "Mars Polar Cap Mystery Solved" (http://www.marstoday.com/viewpr.html?pid=13914). Mars Today. 25 March2004. Retrieved 2007-01-23.

69. A Smith, Isaac B.; Holt, J. W. (2010). "Onset and migration of spiral troughs on Mars revealed by orbital radar"

(http://www.nature.com/nature/journal/v465/n7297/full/nature09049.html). Nature 465 (4): 450453.Bibcode:2010Nature....32..450P (http://adsabs.harvard.edu/abs/2010Nature....32..450P). doi:10.1038/nature09049(http://dx.doi.org/10.1038%2Fnature09049).

70. A "Mystery Spirals on Mars Finally Explained" (http://www.space.com/8494-mystery-spirals-mars-finally-explained.html). Space.com. 26 May 2010. Retrieved 2010-05-26.

71. A Burnham, Robert (2006-08-16). "Gas jet plumes unveil mystery of 'spiders' on Mars"(http://www.asu.edu/news/stories/200608/20060818_marsplumes.htm). Ari]ona State Universit\ web site.Retrieved 2009-08-29.



72. A Kieffer, Hugh H.; Christensen, Philip R.; Titus, Timothy N. (2006-08-17). "CO2 jets formed by sublimationbeneath translucent slab ice in Mars' seasonal south polar ice cap"

(http://www.nature.com/nature/journal/v442/n7104/full/nature04945.html). Nature (Nature Publishing Group) 442(7104): 793796. Bibcode:2006Natur.442..793K (http://adsabs.harvard.edu/abs/2006Natur.442..793K).doi:10.1038/nature04945 (http://dx.doi.org/10.1038%2Fnature04945). PMID 16915284(//www.ncbi.nlm.nih.gov/pubmed/16915284). Retrieved 2009-08-31.

73. A The Solar Wind at Mars (http://science.nasa.gov/headlines/y2001/ast31jan_1.htm)

74. A Madeleine, J. et al. 2007. Mars: A proposed climatic scenario for northern mid-latitude glaciation. Lunar Planet.Sci. 38. Abstract 1778.

75. A Madeleine, J. et al. 2009. Amazonian northern mid-latitude glaciation on Mars: A proposed climate scenario.Icarus: 203. 300-405.

76. A Mischna, M. et al. 2003. On the orbital forcing of martian water and CO2 cycles: A general circulation modelstudy with simplified volatile schemes. J. Geophys. Res. 108. (E6). 5062.

77. A Touma J. and J. Wisdom. 1993. The Chaotic Obliquity of Mars" Science 259, 12941297.

78. A Laskar, J., A. Correia, M. Gastineau, F. Joutel, B. Levrard, and P. Robutel. 2004. Long term evolution andchaotic diffusion of the insolation quantities of Mars" Icarus 170, 343-364.

79. A Levy, J., J. Head, D. Marchant, D. Kowalewski. 2008. Identification of sublimation-type thermal contractioncrack polygons at the proposed NASA Phoenix landing site: Implications for substrate properties and climate-driven morphological evolution. Geophys. Res. Lett. 35. doi:10.1029/2007GL032813(http://dx.doi.org/10.1029%2F2007GL032813)

80. A Levy, J., J. Head, D. Marchant. 2009a. Thermal contraction crack polygons on Mars: Classification, distribution,and climate implications from HiRISE observations. J. Geophys. Res. 114. doi:10.1029/2008JE003273(http://dx.doi.org/10.1029%2F2008JE003273)

81. A Hauber, E., D. Reiss, M. Ulrich, F. Preusker, F. Trauthan, M. Zanetti, H. Hiesinger, R. Jaumann, L. Johansson,A. Johnsson, S. Van Gaselt, M. Olvmo. 2011. Landscape evolution in Martian mid-latitude regions: insights fromanalogous periglacial landforms in Svalbard. In: Balme, M., A. Bargery, C. Gallagher, S. Guta (eds). MartianGeomorphology. Geological Society, London. Special Publications: 356. 111-131

82. A Laskar, J., A. Correia, M. Gastineau, F. Joutel, B. Levrard, and P. Robutel. 2004. Long term evolution andchaotic diffusion of the insolation quantities of Mars" Icarus 170, 343-364.

83. ^D E Mellon, M., B. Jakosky. 1995. The distribution and behavior of Martian ground ice during past and presentepochs" J. Geoph\s. Res. 100, 1178111799.

84. A Schorghofer, N., 2007. Dynamics of ice ages on Mars" Nature 449, 192194.

85. A Madeleine, J., F. Forget, J. Head, B. Levrard, F. Montmessin. 2007. Exploring the northern mid-latitudeglaciation with a general circulation model. In: Seventh International Conference on Mars. Abstract 3096.

86. ^D E Steinn Sigursson. "Global warming on Mars?" (http://www.realclimate.org/index.php?p=192). RealClimate.Retrieved 2007-02-21.

87. A Jacques Laskar (2002-09-25). "Martian 'wobbles' shift climate"(http://news.bbc.co.uk/1/hi/sci/tech/2280991.stm). BBC. Retrieved 2007-02-24.

88. A Francis Reddy. "Titan, Mars methane may be on ice" (http://www.astronomy.com/asy/default.aspx?c=a&id=4009). Astronomy Magazine. Retrieved 2007-03-16.

89. ^D E Malin, M. et al. 2010. An overview of the 19852006 Mars Orbiter Camera science investigation. MARSINFORMATICS. http://marsjournal.org

90. A "MOC Observes Changes in the South Polar Cap"(http://mars.jpl.nasa.gov/mgs/msss/camera/images/CO2_Science_rel/index.html). Malin Space Science Systems.Retrieved 2007-02-22.

91. A "Evaporating ice" (http://www.astronomy.com/asy/default.aspx?c=a&id=3503). Astronomy.com. Retrieved2007-02-22.

92. A Orbiter's Long Life Helps Scientists Track Changes on Mars(http://mpfwww.jpl.nasa.gov/mgs/newsroom/20050920a.html)

93. A Mars Emerging from Ice Age, Data Suggest (http://www.space.com/scienceastronomy/mars_ice-age_031208.html)



94. ^ Colaprete, A; Barnes, JR; Haberle, RM; Hollingsworth, JL; Kieffer, HH; Titus, TN (2005-05-12). "Albedo of the

South Pole of Mars.". Nature 435 (7039): 184188. Bibcode:2005Natur.435..184C(http://adsabs.harvard.edu/abs/2005Natur.435..184C). doi:10.1038/nature03561(http://dx.doi.org/10.1038%2Fnature03561). PMID 15889086 (//www.ncbi.nlm.nih.gov/pubmed/15889086).

95. ^ Jakosky, Bruce M.; Haberle, Robert M. (1990). "Year-to-year instability of the Mars Polar Cap". J.Geoph\s Res

95: 13591365. Bibcode:1990JGR....95.1359J (http://adsabs.harvard.edu/abs/1990JGR....95.1359J).doi:10.1029/JB095iB02p01359 (http://dx.doi.org/10.1029%2FJB095iB02p01359).

96. ^ Fenton, Lori K.; Paul E. Geissler and Robert M. Haberle (5 April 2007). "Global warming and climate forcing by

recent albedo changes on Mars" (http://humbabe.arc.nasa.gov/~fenton/pdf/fenton/nature05718.pdf). Nature 446(7136): 646649. Bibcode:2007Natur.446..646F (http://adsabs.harvard.edu/abs/2007Natur.446..646F).doi:10.1038/nature05718 (http://dx.doi.org/10.1038%2Fnature05718). PMID 17410170(//www.ncbi.nlm.nih.gov/pubmed/17410170). Retrieved 2007-09-06.

97. ^ Access : Hot times in the Solar System : Nature News (http://www.nature.com/news/2007/070402/full/070402-7.html)

98. ^ Fenton, Lori K.; Geissler, Paul E.; Haberle, Robert M. (2007). "Global warming and climate forcing by recent

albedo changes on Mars" (http://humbabe.arc.nasa.gov/~fenton/pdf/fenton/nature05718.pdf). Nature 446 (7136):646649. Bibcode:2007Natur.446..646F (http://adsabs.harvard.edu/abs/2007Natur.446..646F).doi:10.1038/nature05718 (http://dx.doi.org/10.1038%2Fnature05718). PMID 17410170(//www.ncbi.nlm.nih.gov/pubmed/17410170).

99. ^ "Look to Mars for the truth on global warming" (http://www.canada.com/nationalpost/story.html?id=edae9952-3c3e-47ba-913f-7359a5c7f723&k=0). National Post. Retrieved 2007-03-02.

100. ^ "Global warming on Mars, ice caps melting" (http://www.skepticalscience.com/global-warming-on-mars-intermediate.htm). Skeptical Science. Retrieved 17 September 2013.

101. ^ Ker Than (12 March 2007). "Sun Blamed for Warming of Earth and Other Worlds"(http://www.livescience.com/environment/070312_solarsys_warming.html). Live Science. Retrieved 2007-09-06.

102. ^ Kate Ravilious. "Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says"(http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html). National Geographic Society.Retrieved 2007-03-02.

103. ^ Hargitai Henrik (2009). "Climate Zones of Mars" (http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1199.pdf).Lunar and Planetary Institute. Retrieved 2010-05-18.

104. ^ http://www.cbsnews.com/8301-205_162-57487070/curiosity-rover-touches-down-on-mars/

Further reading

Jakosky, Bruce M.; Phillips, Roger J. (2001). "Mars' volatile and climate history". Nature 412 (6843): 237

244. doi:10.1038/35084184 (http://dx.doi.org/10.1038%2F35084184). review article

E[ternal links

NASA Martian Climate page (http://mars.jpl.nasa.gov/science/climate/)

Mars Today (http://humbabe.arc.nasa.gov/MarsToday.html), current conditions on Mars.Nature study explains mystery of Mars icecaps. (http://www.physorg.com/news4106.html)Mars could be undergoing major global warming (http://www.newscientist.com/article.ns?id=dn1660)

Mars Global Surveyor MOC2-1151 Release(http://www.msss.com/mars_images/moc/2005/07/13/index.html)

Global warming on Mars? (http://www.realclimate.org/index.php?p=192)Images of melting ice cap: Evidence for Recent Climate Change on Mars

(http://mars.jpl.nasa.gov/mgs/msss/camera/images/CO2_Science_rel/index.html)



Article from National Geographic on the issue of Martian Global Warming

(http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html)Weather Reports (http://cab.inta-csic.es/rems/marsweather.html) from the Curiosity Rover (REMS)(http://cab.inta-csic.es/rems)

HRSC Clouds (http://hrscview.fu-berlin.de/cgi-bin/ion-p?ION__E1=UPDATE%3Aion%3A%2F%2Fhrscview2.ion&ION__E2=control%3Aion%3A%2F%2Fhrsc

view2.ion&image=9520_0000&image1=3+images&pos=32.704N%2C+297.883E&scale=80&viewport=900x900&basemap_on=on&basemap=MOLAelevation&labels_on=on&hrsc_on=on&mode=nd&panshar

pen=on&ir2re=on&persp=on&pview=South&exag=1&UPDATE=Update+view&image0=9520_0000&code=91663528)

Retrieved from "http://en.wikipedia.org/w/index.php?title=Climate_of_Mars&oldid=597526708"

Categories: Mars Climate history

This page was last modified on 28 February 2014 at 14:39.

Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply.By using this site, you agree to the Terms of Use and Privacy Policy.

Wikipedia is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.

Documents

Climate of Mars - Wikipedia, The Free Encyclopedia