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Ganymede, Jupiter’s Moon, May Function as a Massive Dark Matter Detector

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View of Ganymede from NASA’s Juno spacecraft

junocam/nasa/jpl-caltech/swri/msss/kalleheikki kannisto

Ganymede, one of Jupiter’s moons, has the potential to act as a significant dark matter detector, with upcoming space missions possibly unveiling unique dark matter craters on its ancient terrain.

Researchers typically seek dark matter by looking for lightweight particles that seldom interact with normal matter, employing large, insulated underground detectors. Alternatively, another category of dark matter particles could grow from the size of a basketball to that of an asteroid, but these are infrequent and interact rarely with conventional matter. To detect these hefty dark matter particles, a detector of lunar or planetary scale is necessary to account for their scarcity.

William Derocco from the University of Maryland has proposed that Ganymede, the solar system’s largest moon, may hold clues to these large dark matter particles. His research indicates that they could create a unique crater on the moon’s icy surface, preserved for millions of years due to its stable geology.

Derocco estimates the extent to which these giant dark matter particles penetrate Ganymede’s thick ice layers, finding that they reach the subterranean oceans, fostering unique minerals deeper than a standard asteroid might.

Future missions, such as NASA’s Europa Clipper and ESA’s JUICE, might be able to identify these dark material craters from orbit. Derocco believes these features will be relatively small and distinct, separated from other geological formations. He suggests that “if an underground intrusion radar is used, it may reveal this melted ice column extending down through the ice.”

Utilizing a moon-sized dark matter detector could help identify particles that elude detection on Earth, according to Zachary Picker from UCLA. He states, “Experiments on Earth struggle to find dark matter particles the size of a bowling ball. Particles the size of a refrigerator or car have interactions that are too infrequent.”

The proposal is thorough and well-reasoned, as noted by Bradley Cabana from the University of Cantabria in Spain. “There’s no compelling physical rationale to assume the existence of such massive dark matter particles,” he states. “It’s about exploring all possibilities.” He describes these as extraordinary objects, incredibly dense and held together by formidable forces from obscure sectors.

Topics:

  • Dark matter/
  • Space exploration

Source: www.newscientist.com

Recent research indicates that a giant asteroid collided with Ganymede 4 billion years ago

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Jupiter’s moon Ganymede is home to an ancient impact structure called the Groove System, the largest impact structure in the outer Solar System, whose impact would have had a major impact on Ganymede’s early history.

The distribution of grooves and the location of the center of the groove system are always shown on the hemisphere away from Jupiter (top) and on a cylindrical projection of Ganymede (bottom). Grey areas represent geologically new terrains that are devoid of grooves. Gutters (green lines) are only present in geologically older terrains (black areas). Image courtesy of Naoyuki Hirata, doi: 10.1038/s41598-024-69914-2.

Ganymede is the largest moon in the solar system and has many unique features, including tectonic valleys known as grooves.

The grooves are the oldest surface features identified on Ganymede, as they are crossed by impact craters over 10 km in diameter. The grooves provide clues to the moon’s early history.

The trench is thought to be a fragment of a multi-ring impact basin structure similar to the Valhalla basin on Callisto and the Asgard basin.

The largest trench system lies across the Galileo-Marius region, the so-called Galileo-Marius trench system, which is the remnant of an ancient giant impact that radiates in concentric circles from a single point on Ganymede.

“Jupiter’s moons Io, Europa, Ganymede, and Callisto each have interesting features, but what caught my attention were the grooves on Ganymede,” said planetary scientist from Kobe University. paper Published in the journal Scientific Reports.

“We know that this feature was created by an asteroid impact about 4 billion years ago, but we didn’t know how large that impact was or how it affected the Moon.”

First, Dr. Hirata noticed that the estimated location of the impact was almost exactly on the meridian farthest from Jupiter.

“Similarities with the Pluto impact that shifted the dwarf planet’s rotation axis, as seen through NASA’s New Horizons spacecraft, suggest that Ganymede underwent a similar reorientation,” he said.

The asteroid that struck Ganymede was probably about 300 kilometers (180 miles) in diameter, roughly 20 times larger than the Chicxulub asteroid that smashed into Earth 65 million years ago, ending the age of the dinosaurs, leaving a temporary crater 800 to 1,000 miles (1,400 to 1,600 kilometers) across, according to the study.

Only an impact of this magnitude would be likely to shift the Moon’s rotation axis to its current position due to the change in mass distribution, regardless of where on the surface the impact occurred.

“We want to understand the origin and evolution of Ganymede and other Jupiter moons,” Dr. Hirata said.

“The giant impact must have had a major impact on Ganymede’s early evolution, but the thermal and structural effects of the impact on Ganymede’s interior remain largely unexplored.”

“We think that further research into the application of the internal evolution of icy moons could be done next.”

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N. Hirata. 2024. Giant impact on early Ganymede and subsequent reorientation. Scientific Reports 14, 19982. doi: 10.1038/s41598-024-69914-2

Source: www.sci.news