Mercury Is Not Alone In Orbit, And Scientists Don’t Know Why – Eos

Mercury is not alone in its orbit, and scientists still don’t know why.

A cloud of cosmic dust follows Earth’s closest approach to the Sun. And although other planets, like Earth and Venus, also have a dusty companion in their seasonal journeys, Mercury really shouldn’t.

In a new study published in International Journal of Science, Scientists have tried to find the origin of Mercury dust. And although they still don’t know how this possible cloud formed, they do know that it probably has a different origin story than the one that accompanied our planet.

Traffic Orbital Traffic

A ring of terrestrial dust formed from a giant cloud of dust, called the zodiacal or interplanetary dust cloud, which occupies the space between the stars.

Interstellar dust comes from a variety of sources including interstellar collisions, cometary actions, and cometary explosions. Scattered through the cloud are densely packed regions that host the comet’s paths, dense dust in interstellar belts, and rings of dust near stars. Unlike the well-known rings of Saturn, however, even the largest regions in the dust cloud can be detected using only sophisticated instruments.

The dust particles travel through the solar system, and are pulled towards the Sun. But, like travelers on the road, they make stops along the way.

For example, as grains formed in the asteroid belt move towards the Sun, they cross paths with the inner planets. Planets like Mars are relatively small and have very little gravity, so dust travels through them without much trouble, but more massive planets like Earth can trap debris in their orbits.

Once trapped, the stars and dust move in lock-step in a so-called orbital resonance. Like a musical instrument, the dust-locked worlds move together in the same measure: in perfect harmony, two revolutions of dust for every revolution of the world, three revolutions of dust for every two revolutions of the world, and others.

Eventually, the dust escapes the cosmic dance and continues to migrate—until it meets the next planet. “Like [they are] in heavy traffic on the highway,” said David Nesvorný, a researcher at the Southwest Research Center in Boulder, Colo., who was not involved in the latest study. “You need to stop, and then start moving again until the next jam.”

Effect on Salvation

Earth and Venus have enough to prevent dust migration, but Mercury doesn’t.

Earth and Venus have enough to prevent dust migration, but Mercury doesn’t. This close to the Sun, the elements including the solar wind, solar radiation, and strong magnetic fields should, naturally, kick dust into the sky, and Mercury is not strong enough to capture space debris in its gravitational pull.

These conditions, scientists argue in the new study, means that the rings of Mercury can not form as the Earth did. The ring probably wasn’t fed by a comet or asteroid blowing the planet’s wind, either.

After taking out the dust source, the team turned their attention to Mercury itself. What if a satellite or a comet falls into this world? The impact of a large body would eject matter from Earth’s gravitational well and into orbit to form the dust ring we see today.

True, but Not Confirmed

The rings around Mercury are young, so to test the theory, the team needed to find evidence of a recent collision. “We concluded that nothing could have lived there for more than 20 million years,” said Petr Pokorný of the Catholic University of America and NASA Goddard Flight Center, who led the study.

Using data from NASA’s MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) spacecraft, the team discovered two craters larger than 40 kilometers in diameter on Mercury’s surface that could be less than 50 million years old. Cohesive debris from these attacks likely littered space.

“At the moment, the news is not good.”

To test whether this makes sense, the authors built a simple effect model and showed that in principle, this scenario could work. However, a closer look shows that the information does not add up. “At the moment, the news is not good,” said Pokorný.

For example, scientists estimate that the size of the ring is equal to that of an asteroid with a diameter of 1-1.5 km. These two effects alone cannot account for all the dust in circulation.

Perhaps, the authors wrote, several small asteroids could hit Mercury and add to the debris. This theory is reasonable, but it is difficult to test because of the small size of the small size and the small size of the small size is a challenge to date. The old craters drip when they are hit by recent asteroids, so scientists can date a crater based on how it is marked. Mallory Kinczyk, a postdoctoral researcher at Johns Hopkins University’s Laboratory of Physics, who was not involved in the new study, said: reduction.” Judging the age based on only a few well-known holes will lead to inaccurate estimates, Kinczyk said.

Nesvorný does not believe that small asteroid impacts will solve the problem, however. The model presented in the latest study predicts that only a fraction of the emission from the Earth’s surface will transfer to space. Stronger designs can prioritize more efficient transfers, he said. If so, then perhaps the two main effects the team discovered are enough to explain the rings. For now, though, the case remains open.

– Jure Japelj, Science writer

Solution: Japelj, J. (2023), Mercury is not alone in orbit, and scientists don’t know why, Yau, 104, doi.org/10.1029/2023EO230069. Posted on February 27, 2023.

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