Mars is the only planet in the solar system where dust storms can encircle the entire globe. This page tracks all major documented events and explains the seasonal cycle that drives them — with implications for every solar-powered mission.
5
Global Storms
8
Total Events
3–5
Mars Years Between Globals
104
Days (2018 Storm Duration)
1971-09-22 → 1972-01-01 · 100 days
Peak opacity: Effectively opaque from orbit — entire disk featureless in visible light
The 1971 global dust storm was the first planet-encircling storm observed from orbit by NASA's Mariner 9 and the Soviet Mars 2/3 orbiters. When Mariner 9 arrived on November 13, 1971, it found the entire Martian disk obscured; only the summits of Olympus Mons and the three Tharsis Montes protruded above the dust. Mariner 9's controllers placed the spacecraft in a holding orbit for roughly three months before the atmosphere cleared sufficiently for systematic mapping to begin. The storm almost certainly contributed to the 20-second failure of the Mars 3 lander on December 2, 1971.
Missions Affected:
1977-06-05 → 1977-07-20 · 45 days
The first of two global dust storms observed by the Viking mission in 1977 developed in the southern hemisphere during local summer and expanded planet-wide over several weeks. Viking lander meteorology instruments recorded elevated wind speeds and pressure fluctuations, while Viking orbiter cameras tracked the storm's evolution for the first time from an orbiting platform. This storm, combined with the second 1977 event, provided the first systematic dataset for modelling dust storm initiation and global transport.
Missions Affected:
1977-08-23 → 1977-10-05 · 43 days
A second planet-encircling storm developed just weeks after the first 1977 event cleared, reaching global scale by early September. Viking instruments captured the storm's rapid expansion and decay, and the back-to-back occurrence of two global storms within a single Martian year was unexpected — it demonstrated that global storms can cluster temporally and is still not fully explained by global circulation models. Together the two 1977 storms remain the most systematically studied pair of global Mars dust events in the pre-Mars Global Surveyor era.
Missions Affected:
2001-06-26 → 2001-11-01 · 128 days
Peak opacity: Tau > 5 at multiple locations (near-complete solar opacity at surface)
The 2001 global dust storm was the largest observed in the modern robotic era at the time of occurrence, and the first to be tracked continuously by an orbiting spacecraft (Mars Global Surveyor) from initiation through decay. It began as a regional storm in Hellas Basin before expanding planet-wide within two weeks. The storm's peak opacity made surface solar illumination comparable to a heavily overcast Earth day. Mars Odyssey's arrival during the storm's decay required mission planners to adjust its aerobraking profile, as the elevated dust had expanded the upper atmosphere.
Missions Affected:
2018-05-30 → 2018-09-11 · 104 days
Peak opacity: Tau > 8.0 at Opportunity's Perseverance Valley location — complete opacity
The 2018 global dust storm was the most thoroughly studied planet-encircling Mars dust event in history, tracked by five orbiters and two surface vehicles simultaneously. Opportunity's solar panels were completely blanketed; the rover sent its last transmission on June 10, 2018, and never recovered. Curiosity, powered by an RTG, drove through the storm providing unprecedented in-situ measurements of dust loading, temperature profiles, and atmospheric opacity during a global event. The storm lasted approximately 104 days from first detection to global clearing, and its detailed observation record has transformed atmospheric modelling of dust storm initiation and global transport mechanisms.
Missions Affected:
2007 · 53 days
Tau ~5.5 at Opportunity's location (solar panel output fell to <1% of normal)
The 2007 regional dust storm presented the most severe threat to surface solar-powered missions since the Viking era. At its peak, Opportunity's solar panel output dropped to less than 1% of normal levels, forcing the rover into a near-total hibernation mode with only survival heaters active. JPL engineers monitored power margins daily and prepared contingency plans for a permanent loss of communication. Opportunity survived; when the storm cleared, wind gusts unexpectedly cleaned dust from the solar panels, restoring power levels higher than before the storm. The event shaped future mission planning for dust event survivability.
2019 · 54 days
The first regional dust storm following the 2018 global event offered scientists an opportunity to study the Martian atmosphere as it returned to a more typical dust regime. Curiosity measured the storm's opacity and documented its limited spatial extent, confirming it remained well below global-storm intensity. The event helped validate models of storm size prediction and post-global-event atmospheric recovery timescales.
2021
Perseverance's MEDA meteorology instrument detected hundreds of dust devil passages across its first Martian year of surface operations at Jezero Crater, providing the highest-cadence record of dust devil activity for any Mars landing site to date. Several vortices were captured on camera, and pressure-drop signatures were used to derive vortex diameter and strength statistics. Dust devils at Jezero are more frequent than at InSight's Elysium Planitia site, consistent with Jezero's lower latitude and stronger summer insolation. Dust devil activity is a primary mechanism for lofting dust into the Martian lower atmosphere during non-storm periods.
Mars dust activity follows a strongly seasonal pattern tied to orbital position (solar longitude Ls) and the eccentricity of Mars's orbit. Because Mars's orbit is significantly more elliptical than Earth's (eccentricity ~0.093), the planet receives ~40% more solar energy at perihelion (Ls 251°) than at aphelion (Ls 71°). This pronounced annual forcing drives a predictable dust season centred on southern summer / perihelion passage. The northern hemisphere spring and summer (Ls 0°–180°) is the quietest dust period. Local and regional storms can initiate at any season but are statistically much more likely from Ls 180° onward.
Peak Risk Season
Southern summer (Ls 180°–310°) — Mars is closest to the Sun at perihelion (Ls 251°), maximising solar heating and atmospheric instability. All known planet-encircling dust storms have initiated between Ls 180° and Ls 310°.
Global Storm Frequency
~1 planet-encircling storm every 3–5 Mars years on average, based on the observational record from 1971 to 2026. Events have occurred in: 1971, 1977 (×2), 1982, 1994 (partial), 2001, 2018. Not every perihelion season produces a global event.
Regional Storm Frequency
~1–2 regional storms per Mars year (approximately every 687 Earth days), concentrated in the Ls 180°–310° season window.
Dust Devil Season
Dust devils peak in northern and southern summer respectively, driven by strong daytime convection. They are most active at mid-latitudes in summer, typically occurring between 09:00–15:00 local solar time. They contribute a background aerosol loading of tau ~0.3–0.6 but do not cause global storms.
Mission Impact
Solar-powered missions face the greatest risk during perihelion dust season. Power reduction of 50–99% is possible during regional or global storms. Nuclear-powered missions (Curiosity, future missions) are immune to power loss but still experience instrument exposure and reduced visibility. Dust deposition rates and occasional cleaning events (wind gusts) determine long-term solar panel efficiency trends.
Global storms require not just initiation but positive feedback: once dust loading exceeds a threshold, radiative heating of the dust layer accelerates upper-level winds that lift still more dust, creating a runaway process. The mechanisms that determine whether a regional storm 'goes global' in any particular year are not fully understood and remain an active area of research.