Observations of Flares on Mars

Flare Sightings by the Japanese

In December of 1949 Tsuneo Saheki recorded a "brilliant glow" on Mars. The brilliant glow lasted for several minutes and Saheki interpreted it as an atmospheric nuclear explosion. What Saheki saw was not a man-made event, but a natural atmospheric explosion, which may explain why the explosion lacked the "double signature" that usually goes with nuclear warheads. Saheki also recorded a yellow-grey "luminescent cloud" some 700 miles in diameter that formed after the initial explosion. The yellow cloud may have been a cloud of Martian dust, as seems natural, but Saheki noted that it reached a height of 40 miles. Since the atmosphere of Mars is only 60 miles high, the dust cloud reached two-thirds of the way to outer space! Another explanation is that the cloud was a layer of atomic sodium residing in the atmosphere. This layer was ionized by the blast, and minutes later gave off a clearly visible yellow glow when it recombined after being ionized.

On November 6 1958, S. Tanabe recorded a Martian "flare". A few days later, on November 10, S. Fuikui recorded a second Martian flare. It's not entirely clear that these were natural phenomena. October of 1958 was an Earth-Mars opposition, when the distance between the planets is shortest. Studies have shown a relationship between such an opposition and decametric radiation from Jupiter and perhaps Saturn. Such oppositions also create magnetic disturbances in the Earth's atmosphere. So it's not out of the question for these oppositions to have an effect on Mars.

Solar flares generally occur in a 26-month pattern that matches the oppositions of Earth and Mars. The solar wind is ejected from the Sun at about 360 kilometers per second, and the distance between the Sun and Earth is about 149.5 million kilometers, so that a solar shockwave would take about 5 days to reach Earth, and about 8 days to reach Mars. Thus solar flares may be partly responsible for the flare sightings on Mars.

Solar flares excited by galactic cosmic radiation are "relativistic," which means they travel near the speed of light, something like radio waves. A similar relativistic effect might be created by a nuclear blast. It's possible that the British nuclear tests conducted in the Pacific in September of 1958 sent some relativistic radiation towards Mars, but a relativistic shockwave would reach Mars in minutes. The flares were seen on Mars 65 days later. Thus, nuclear tests in September can't explain the flares that were observed on Mars in November.

However, there's a more intriguing explanation, though it lacks any kind of evidence to support it. Did the British and Americans send two nuclear warheads to Mars? For example, nuclear testing in the Pacific by the British and Americans may have been a way to "open a hole" in the atmosphere for rockets to be fired into outer space. If a rocket was fired from the Pacific on September 2 on a trajectory to Mars, and it traveled 60,000 miles per hour, it would travel 93,600,000 miles in 65 days, which on a parabolic arc would certainly cover the distance between Earth and Mars during a good opposition. The opposition of August 1956 was "perfection" meaning it was very close, so October 1958 would have been "good." There's no evidence that the British and Americans did this, but it would explain the Martian flares and the delay between the Earth events and the Mars sightings.

Project A119
The first volume of the Air Force's Project A119 has been released online, and offers a possible solution to the Mars flare mystery. Project A119 was funded by the Air Force and it investigated the scientific and political ramifications of detonating an atomic bomb on or near the surface of the Moon. Interestingly, Carl Sagan wrote Chapter VIII, "Organic Matter and the Moon," which is vastly entertaining in the classic Sagan style. He postulated that the Moon does indeed harbor complex organic molecules beneath its surface. But the more relevant portion of the study is Chapter III, "Optical Studies Related to the Lunar Research Flights," and specifically Section F, "Sodium Vapor."

The Project A119 report is cautious throughout about the reality of sending a nuclear warhead to the Moon -- the dangers are well delineated. The study was carried out with the participation of the Armour Research Foundation from May 1958 to January 1959. Volume I, available online, was published in June 1959.

Section F outlines a plan to use sodium vapor in the lunar atmosphere instead of an atomic bomb. The study mentions U.S. experiments from 1955 in which sodium was vaporized in the atmosphere at an altitude of 30 to 40 kilometers (18 to 25 miles) to study chemical reactions with sodium as well as wind directions at these altitudes. "The sodium cloud is discharged at a specific moment and it glows because of resonance fluorescence emitting the sodium lines." The study pointed out that the yellow light of sodium vapor "is preferred from the point of view of visual sensitivity." The authors further noted that narrow band interference filters can enhance the contrast from the observation standpoint.

The brilliance of a sodium cloud containing a kilogram of sodium, discharged 113,000 km (70,200 miles) from Earth, is equal to a sixth magnitude star. This brightness is at the threshold of naked eye visibility against an average sky background. The study concluded that 100 kilograms of sodium would be visible against the Moon's dark side with the naked eye. The authors added that "the sodium requirements are substantially reduced when appropriate telescope magnification is employed."

Section F ends with the following advice: "One might envision a dual purpose use of solid propellant rocket motors as (1) retrodirective devices and (2) marking flares in the present context. The propellant, containing sodium, would be released on firing the rockets near the moon. It is quite likely that a known formulation can be used, thus precluding the costly development of a new special propellant formulation. Most likely, formulations currently undergoing development at NOTS (Naval Ordnance Test Station) will be applicable. These formulations include metal additives such as aluminum, boron, and magnesium. Several factors would bear on the amount of light detectable, such as missile configuration, spinning or tumbling, and angle of viewing."

Here then, in a study conducted just before the Argus and Grapple nuclear tests, is a possible modus operandi for the military: the launch of rockets with retro-rocket propellant containing sodium, as opposed to rockets with nuclear payloads. This configuration eliminated the safety concern associated with live nuclear warheads, and lightened the rocket weight at the same time. What was the objective of launching such flare rockets to Mars? Simply this: to hit the target and receive visual confirmation of such. In 1958 nobody had sent a rocket to Mars. If the U.S. could beat the Soviets there, it would be a scientific first and a great victory for the Cold War.

On October 31 1958 President Eisenhower announced a unilateral testing moratorium, with the understanding that the United States and the Soviet Union would refrain from conducting nuclear tests. The Soviet Union broke the moratorium and resumed atmospheric nuclear tests in September 1961. The largest blast ever achieved by the Soviets took place on October 30 1961, with a yield of 58 megatons. There is also evidence that the United States conducted atmospheric tests in 1959 and 1960. However, one must be cautious since there is also evidence that meteor explosions have a very similar signature to atomic explosions in the atmosphere. An Army infrasound network in operation between 1950 and 1974 collected readings on about 100 bolide events in the atmosphere, as well as readings of nuclear explosions.

A Meteor Hit in 1958 on Mars?
One problem with the Project A119 theory is that there was no deep-space radar in 1958, which means there would have been no way to send the minor course corrections to the rockets on their way to Mars. There would have been no way to fire the retro-rockets when the rockets arrived at Mars, to release the sodium vapor cloud.

Two other flares were observed on Mars on November 21 1958 by Ichiro Tasaka. The first was seen at Edom Promontorium at 13:35 Universal Time, and the second at Northern Hellas at 13:50 UT. The sightings mentioned above, by Tanabe and Fuikui, were located northeast of Solis Lacus, and at Tithonius Lacus. Astronaut Clark McClelland observed a flare on Mars at the Allegheny Observatory on July 24 1954. He hypothesized that the flare was a volcanic eruption. Tsuneo Saheki, who observed a Martian flare in 1949, also observed flares in 1951 and on July 1 1954.

The flares observed by McClelland and Saheki in 1954, both at Edom Promontorium, have all the earmarks of a periodic phenomenon caused by specular reflections of sunlight off water-ice crystals in surface frosts or atmospheric clouds, specifically at times when the sub-Sun and sub-Earth points are nearly coincident and close to the planet's central meridian (the imaginary line running down the center of the visible disk from pole to pole). This theory was proposed and subsequently observed by Thomas Dobbins in 2001. Also, Edom Promontorium has historically always been one of the brightest observable spots on Mars.

The simultaneity of events on November 21 1958, as well as the great distance between the flare sites, argues against both volcanic activity and specular reflection, and in favor of two meteors that impacted Mars fifteen minutes apart. There is very little information available about meteor hits on Mars. On Earth, meteors are captured in the mesosphere, about 93 to 96 kilometers in altitude. There they burn out or are ablated, and leave trails of metallic ions, mostly sodium. The photograph below shows two meteors and their explosive disintegration in the center. The line extending from the top border is the laser radar (lidar) beam aimed at the meteor area from the ground, just seconds after the fireball first appeared.

CCD image of two Leonid meteor trails, taken in 1998 from Kirtland AFB, New Mexico.

Strangely enough, Mars also has a "meteor layer" located about 90 kilometers in altitude. This is strange because the Martian surface pressure is about 7 millibars, or less than one percent of Earth's. At 90 kilometers altitude in the Martian ionosphere, the pressure is a thousand times weaker still. Nonetheless, electron densities hold meteor trains at that altitude, both on Earth and on Mars. The graph below shows the three electron density peaks in the Mars ionosphere.

The X-ray and meteor electron-density peaks varied during a six-year observation period.
Solar flares may have partly caused this variation, which also affected the altitude of the meteor layer.

Meteors in the Martian atmosphere follow a seasonal trend that seems to peak every eleven years, with the sunspot cycle. With this background knowledge, the flares seen on November 21 1958 can be explained as either a single bolide that broke into pieces on its collision course with Mars, or as a meteor "stack" in the Mars meteor layer that, because of a solar flare or some other solar disturbance, was pushed out of its high-density trough and exploded due to atmospheric friction. The first flare was seen at Edom Promontorium, at 0 deg S, 15 deg E, at 13:35 UT; and the second flare was seen at Northern Hellas, at 42 deg S, 70 deg E, at 13:50 UT.

The Mars meteor theory finds an analogy in the famous "Great Fireball Procession" of February 1913, which was seen by hundreds of people along a path through Canada and the United States as shown in the map below.

The trajectory of the meteor path of 1913.

The sightings took place from 8:00 pm to 8:10 pm on February 9. Mebane gives a thorough account of the dozens of eyewitness reports, but the main thing to notice is the northwest to southeast trajectory. Both Earth and Mars are inclined 23.5 degrees from the orbital plane, and the meteor path on Earth in 1913 as above, and the path from Edom to Hellas in 1958, are similarly inclined.

The Martian flare seen by Saheki in 1949 lasted for several minutes, much longer than flares attributed to specular reflections, which last about 5 seconds. The flares seen on November 21 1958 were probably similar to Saheki's 1949 sighting. Typically, on Earth anyway, a meteor drills a "tube" into the atmosphere, and this tube is heated to high temperatures around its perimeter, where the meteor is ablated due to friction. The central area of the tube is cooler and isn't as bright. A shockwave generated by a meteor would add more brightness to the impact, even if the meteor blew up in the atmosphere before reaching the ground. If the meteor hit the ground, dust would certainly be raised into the atmosphere: but there is no indication that the hit in 1958 was so drastic.

A meteor swarm was most likely orbiting Mars in the orbital plane. It could be imagined that a vertically-extended swarm or rather "stack" of large meteorites, whose lower end reached down to the 30- or 40-mile-level, was the actual satellite, and that the flares witnessed along its path were caused by the successive "peeling off" of its lower members by the air as the stack slowly lost altitude in its orbital flight. This is the best explanation for the Earth sightings in 1913, when different groups of witnesses saw bright trails and streaks belonging to different parts of the "procession."

The sightings were of slow-speed bolides in an incandescent state, which formed a chain. It was moreover a "procession" in that the meteors didn't emanate from all directions of a meteor radiant, but were members of clusters of closely related fragments originating from the partial or complete disruption of larger bodies. The clusters broke into groups, and some groups produced a thundering sound (over New York), while others were silent (over New Jersey).

Sound can be attributed to air-racked meteors. No sounds were heard over Michigan, but explosive sounds began to be heard near Hamilton, Ontario. The sounds continued to be heard into Pennsylvania. Thus the Michigan meteors began at a higher level in the atmosphere, gradually dropped downwards, and burnt themselves out somewhere in Pennsylvania after roaring over western New York at a destructively (to the meteor itself) low altitude.

The typical path-length of the 1913 procession, assuming different continuities, is estimated to have ranged from 500 to 750 miles.

On Mars, the length of the path from Edom Promontorium to Northern Hellas can be estimated as 2343 miles. This is too long for the fifteen minute difference in flare observations if one assumes that the bolides are vertically stacked. For comparison, the Mars Rover package took six minutes to make its descent to the Martian surface. One minute into its descent, friction from the atmosphere slowed it to a speed of 3.35 miles per second. The Rover module was about the weight of a light meteor, but a different shape. Therefore, a meteor of comparable size could be expected to hit the surface within six minutes of atmospheric entry.

The scenario can be calculated by assuming: a) a free-space velocity for the bolides of 12 miles per second, which is the high end of the meteor speed scale, which ranges from 3 to 12 miles per second; b) an atmospheric descent velocity identical to the Rover package, 3.35 miles per second; and c) that the top of the Martian atmosphere is 180 miles high. After doing all of the calculations the second bolide will lag behind the first by about 4000 surface miles, and will be higher than the first by about 1000 miles. Thus two separate bolides in the orbital plane of Mars in a train may have come down separately but along the same general path.

Albedo Observations
The meteorite theory has many good points, but one distracting negative point is that Edom Promontorium is one of the impact points. As early as 1896 Edom Promontorium was seen to be very bright by several astronomers. It was seen as especially conspicuous when it was near the limb of the planet. Molesworth in his drawings of the time showed the whole of Edom whitish as far as Euphrates and Orontes, and noted that "on one occassion the Sinus Sabaeus was seen to be notched by a minute circular island jutting out from Edom into the Sinus, south of the estuary of Hiddekel, with apparently a narrow canal separating it from Edom." A contemporary British astronomer noted that "the appearance of a short curved canal limiting the whiteness of Edom Promontorium might be a phenomenon of contrast, carrying us back to Mr. Maunder's theory (1882) that some of the canals might be due to differences in shade in neighboring districts."

In 1905 astronomers at the Lowell Observatory made a note of "light spots" to the effect that "two light areas were visible in Aeria on January 4, one just southwest of Pseboas Lacus, the other on the eastern side of the Sabaeus Sinus gulf, embracing Edom Promontorium. A third lay just across the long filament of the Sabaeus Sinus or Mare Icarium, over against the second in Deucalionis Regio. Edom Promontorium has a way of being bright."

During the opposition of 1939 M. Geddes noted: "Sinus Sabaeus. There was little worthy of note here except that the feature was always very dark, probably the darkest region of Mars. During August Edom Promontorium was the brightest feature on the planet, standing out sharply and clearly." These remarks confirm the large albedo difference between the adjacent regions, which led early astronomers to mistake the contrasts as canals.

Thus it seems very suspicious for Edom Promontorium to also be a meteorite impact site.

Just as Edom Promontorium has been the focus of flare sightings attributed to specular reflection off of ice, it may be that the northern rim of Hellas is also ice-bound. Craters in the eastern region of Hellas basin are associated with ice and glacier formation. Hellas basin is also known as Hellas Planitia. It has a diameter of about 2300 kilometres (1400 miles) and is the largest unambiguous crater on the planet. It's surrounded by an elevated "debris ring." The center part of the crater lies 8 kilometers below the surrounding material. The transition region is where glaciers may have existed in the past, and may continue to exist underground today. Thus, specular reflection off of ice fields near the rim of Hellas may be responsible for flares sighted from Earth during an opposition, just as with Edom Promontorium.

It turns out that a bit of detective work is required to find out where Edom Promontorium really is on today's maps. It turns out it's the northern rim of Schiaparelli crater.

An artist's conception of Schiaparelli crater after Mars terraforming has taken place.
The crater is filled with water. The artist has even added clouds. Note that the lower
right-hand region is uplands, and that a rivercourse empties into the crater.

This is the real deal taken by one of the Viking orbiters. The river channel is conspicuous
as a dark crack along the southeastern rim of the crater. Notice the dark area south
of the crater, known as Sinus Sabaeus in the albedo terminology. It's shown as green hills
in the terraforming image above. Could it be green at certain times of the year in reality?

The Viking photograph above shows how the northern rim of Schiaparelli has a much brighter albedo than the area south of it, which shows up very dark. This is the albedo difference that astronomers were seeing through their telescopes in the nineteenth and twentieth centuries.

The easy answer is to attribute flares seen on Mars to solar reflections off of ice or ice clouds. But in all fairness, one must finally attribute different sightings to different causes, and in general leave the issue open.


Clouston and Gaydon. Excitation of Molecular Spectra by Shock Waves, Nature 180 : 1342 - 1344, 1957
Wikipedia entry: Project A119, online
Chael, Eric. Whitaker, Rodney. Infrasound Signal Library, 25th Seismic Research Review, 1994?, online
Chu, Kelly, Drummond et al. Lidar Observations of Elevated Temperatures in Bright Chemiluminescent Meteor Trails..., Geophysical Research Letters, Vol. 27, No. 13, 2000, online
Withers et al. Space weather effects on the Mars ionosphere due to solar flares and meteors, EPSC 2006, online
Mebane, A.D. Observations of the Great Fireball Procession of 1913 February 9, Made in the United States, Journal of Meteoritics, Vol. 1, Number 4, p. 405, 1956, online

Outer Space

Home Page