Rough Notes:

Ionized Moon

  

Six views of Phobos. Credit: A. Tayfun Oner. Click to enlarge.

 

Nov 1, 2017

Phobos could be electrically charged.

Of the two Martian moons, Phobos is the largest, at 28 by 20 kilometers. Its most prominent feature is Stickney crater, a ten-kilometer-wide excavation that is almost as large as Phobos, itself. If the crater was caused by the impact of an asteroid, it should have blasted the moon into fragments, yet there is little sign of any blast debris.

There are what appear to be fracture lines around Stickney, so some astronomers assert that they are evidence for a severe shock, and that they were distorted by an impact. Closer examination reveals that the striations are, in reality, chains of small craters and not cracks. In fact, the crater is rounded and smooth, with no large breccias, although Phobos is covered with almost a meter of ultra-fine dust.

Phobos is about the same size as asteroids Mathilde, Eros and Ida, and it exhibits features like the relatively gigantic craters that are endemic to those bodies, so what is the common event that creates such similar structures without obliterating the objects in the first place? The answer is electricity.

In previous Pictures of the Day about Mars, scenarios for how it was devastated by electric arcs in the recent past were presented. Those events gouged-out Valles Marineris, Olympus Mons and Arabia Terra in a relatively short period, ejecting gigatons of rock from the planet. Could it be that Phobos and Deimos are remnants of that overwhelming cataclysm?

The thunderbolts that carved up Mars threw big chunks of its crust into orbit, as well as into long ellipses around the Sun. They were smoothed and eroded by the arcs while accelerating through the planet’s electric fields. Touchdown points where the electric discharges were most intense became deeply incised craters. That is why Phobos and the asteroids mentioned are covered in dust, have little or no large boulders, and are defined by huge craters that look like they are half-melted.

Phobos is composed of iron oxide, silicon dioxide, various carbonates and other ceramic compounds, so it is nearly identical to the surface composition of Mars. According to a recent press release, the presence of so much dust could present a problem to any missions designed to land on the moon because, “… powerful solar eruptions could electrically charge areas of the Martian moon Phobos to hundreds of volts…”

In 1998, the Lunar Prospector detected a surprisingly high voltage as it passed through Earth’s magnetotail, a part of the plasma sheath that envelops our planet. The Moon passes through it once a month during full moon phase; the electric differential was found to occur during that passage. The Moon passage through the ionized plasma affects materials in the lunar regolith. Electrons accumulate, producing a negative charge on the ultra-fine dust particles, causing them to repel each other and drift off the surface. Charge differential between the day and night side of the Moon has been measured at more than 1000 volts.

The press release states that the solar wind charges Phobos. When charged particles strike its day side, they are absorbed by the surface, which might cause astronauts and rovers to accumulate significant electric charges: up to ten thousand volts in some materials. Special electric charge dispersal systems will be needed in order to prevent arcing to instruments or to oppositely charged surface materials.

Stephen Smith

 

Phobos

  
The north pole of Phobos. Credit: ESA/DLR/FU Berlin (G. Neukum)

The north pole of Phobos. Credit: ESA/DLR/FU Berlin (G. Neukum)

 

Jan 21, 2013

Did meteor bombardment scar Phobos?

Phobos is the largest of the two moons of Mars. Deimos is so small that studying its surface has been problematic for astronomers because it cannot be readily observed from Earth. Only the Viking 2 orbiter, and more recently, the HiRise camera onboard the Mars Reconnaissance Orbiter captured close up images. Phobos, on the other hand, has been examined by Earth stations and by satellites sent to Mars orbit.

In the image above, Stickney crater is visible on the left. Stickney is a ten kilometer-wide excavation that is nearly the size of Phobos itself. In previous Thunderbolts Picture of the Day articles, rocky bodies with craters almost as large as themselves have been discussed. As was pointed out, the “impact” craters should have blasted the objects into fragments, but little sign of the collisions is visible other than the craters. In the case of Phobos, the moon is 28 by 20 kilometers in size, so Stickney crater is nearly half as large as the moon.

Some astronomers have reported that the striations and fracture lines evident around Stickney demonstrate that the moon did undergo severe shock, and that it was distorted by the impact of whatever formed the crater. However, on closer examination it was revealed that the striations are, in reality, chains of small craters. No “fracture lines” are visible – no cracks as if from a titanic shock wave passing through the moon’s body. In fact, the area surrounding the crater is rounded and smooth with no large blast debris (although the moon is covered with almost a meter of finely divided dust).

Because Phobos is in the same size range as some asteroids such as Mathilde, Eros and Ida, and it exhibits features like the relatively gigantic craters that are endemic to those bodies, what is the common event that creates such similar structures without obliterating the objects in the first place? The answer is electricity.

In past reviews of Mars, for example, it appears that the Red Planet was immersed in a plasma flame sufficiently large to gouge out Valles Marineris, Olympus Mons and Arabia Terra in a relatively short period. Gigatons of rock and dust were literally ejected from the planet and thrown into space at escape velocity. Blocks of stone as large as Manhattan Island look like they fell from a great height and shattered on impact, leaving fields of enormous boulders with sharp, angular edges covering hundreds of square miles. Could it be that Phobos, Deimos, Ida and the rest are also the remnants of that overwhelming cataclysm?

In a possible scenario, the thunderbolts that carved up Mars threw big chunks of its crust into orbit, as well as into long ellipses around the Sun. While ramming through the electrical fields involved with the EDM process, they were smoothed and eroded by the arcs. Touchdown points where the discharges were more intense became deeply incised. The result is that Phobos and the asteroids mentioned are covered in dust, have little or no large boulders, are defined by huge craters and look like they’re half-melted.

In conclusion, Phobos and Deimos appear to be the remains of a catastrophic event that electrically devastated their parent planet, leaving them as wandering orphans forever looking down on what was once their home.

Stephen Smith

Fear and Panic

  
Phobos

The north pole of Phobos. Credit: ESA/DLR/FU Berlin (G. Neukum)

 

Dec 10, 2015

The two moons of Mars will soon receive a visitor.

According to a recent press release, the Japan Aerospace Exploration Agency (JAXA) plans to launch a probe to the enigmatic Martian moons, Phobos and Deimos. It is hoped that the newly minted mission will return samples of each moon back to Earth.

The last time a spacecraft was scheduled to visit the Martian moons was the ill-fated Phobos-Grunt. It was to observe Phobos and its environment from orbit, as well as place a lander on the surface that would bring samples back to Earth. A Chinese-made orbiter (Yinghuo-1) also flew with Phobos-Grunt. Launched in November 2011, its escape path to Mars failed, contact was lost, and it subsequently burned-up in the atmosphere on January 15, 2012.

Phobos is the largest of the two moons of Mars. Deimos is so small that it is a problem for astronomers because it cannot be easily observed from Earth. Only the Viking 2 orbiter, and more recently, the HiRise camera onboard the Mars Reconnaissance Orbiter captured close up images. Phobos, on the other hand, has been examined by Earth stations and by satellites sent to Mars orbit.

Stickney crater is a ten kilometer-wide excavation that is nearly the size of Phobos itself. In previous Pictures of the Day, rocky bodies with over-sized craters were pointed out. The “impacts” that left such comparatively enormous craters craters should have blasted the objects into fragments, but little sign of the collisions is visible other than the craters. In the case of Phobos, it is 28 by 20 kilometers in size, so Stickney crater is nearly half as large.

Some astronomers report that the striations and fracture lines evident around Stickney demonstrate that the moon did undergo severe shock, and that it was distorted by the impact of whatever formed the crater. However, on closer examination, the striations are revealed as chains of small craters, not “fracture lines” as if from a shockwave passing through the moon’s body. The area around the crater is blunted and smooth, with no large breccias, although the moon is covered with almost a meter of ultra-fine dust.

Phobos is similar in size to some asteroids such as Mathilde, Eros and Ida. It exhibits features, such as the aforementioned gigantic craters, that are endemic to those bodies. What is the common event that created such similar structures without obliterating the objects in the first place? The answer is electricity.

The theory of Mars immersed in a plasma flame sufficiently large to gouge out Valles Marineris, Olympus Mons and Arabia Terra in a relatively short period is the topic of many past Pictures of the Day. Gigatons of rock and dust were ejected from the planet and thrown into space at escape velocity. Blocks of stone as large as Manhattan Island appear as if they then fell from a great height and shattered on impact, leaving fields of enormous boulders with sharp, angular edges, covering thousands of square kilometers. Could it be that Phobos, Deimos, Ida and the rest are also the remnants of that overwhelming cataclysm?

In a possible scenario, the thunderbolts that carved up Mars threw big chunks of its crust into orbit, as well as into long ellipses around the Sun. While ramming through the electric fields involved with that process, they were smoothed and eroded by plasma discharge events at varying potential. For example, touchdown points drilled-in where the discharges were more intense. The result is that Phobos and the asteroids mentioned are covered in dust, have little or no large boulders, are defined by huge craters, and look like they’re half-melted.

Stephen Smith