As club sandwiches go, this would undoubtedly be the biggest one in the solar system: Scientists on Friday last week said that one of Jupiter’s moon’s, Ganymede, may possess ice and liquid oceans stacked up in several layers much like the multilayered sandwich.
This arrangement may raise the chances that the distant icy world harbors life, they said.
NASA’s Galileo spacecraft flew by Ganymede in the 1990s and confirmed the presence of an interior ocean, while also finding evidence for salty water, perhaps from the salt magnesium sulfate.
Photo: Reuters / NASA / Jet Propulsion Laboratory-Caltech
At about 5,300km in diameter, Ganymede is the largest moon in the solar system and dwarfs Mercury.
Friday’s announcement was made by a team of scientists that performed computer modeling of Ganymede’s ocean, taking into account for the first time how salt increases the density of liquids under the type of extreme conditions present inside the moon. Their work followed experiments in the laboratory that simulated such salty seas.
While earlier research suggested a routine “sandwich” arrangement in which there is ice at the surface, then a layer of liquid water and another layer of ice on the bottom, the new study indicated that there might be more layers than that.
Steve Vance, an astrobiologist at NASA’s Jet Propulsion Laboratory in California, said the arrangement might be like this: A layer of ice sits on the moon’s surface, with a layer of water below, then a second layer of ice, another layer of water under that, then a third layer of ice, with a final layer of water at the bottom above the rocky seafloor.
“That would make it the largest club sandwich in the solar system,” Vance said by telephone. “I suppose I’m also a fan of club sandwiches. My fiancee points out that I order them every time we go out to eat.”
Ganymede’s oceans are estimated to be about 800km deep and the moon holds perhaps 25 times more water than Earth’s oceans.
With enough salt, liquid water on Ganymede could become so dense that it sinks to the bottom, the researchers said. That means water may be sloshing on top of rock, a situation that may foster conditions suitable for the development of microbial life.
Some scientists suspect that life first formed on Earth in bubbling thermal vents on the ocean floor.
“Our understanding of how life came about on Earth involves the interaction between water and rock. This [research] provides a stronger possibility for those kinds of interactions to take place on Ganymede,” added Vance, whose study was published in the journal Planetary and Space Science.
Ganymede is one of five moons in the solar system thought to have oceans below icy surfaces. Two of the five, Europa and Callisto, orbit Jupiter, while the other two, Titan and Enceladus, circle Saturn.
‘IN A DIFFERENT PLACE’: The envoy first visited Shanghai, where he attended a Chinese basketball playoff match, and is to meet top officials in Beijing tomorrow US Secretary of State Antony Blinken yesterday arrived in China on his second visit in a year as the US ramps up pressure on its rival over its support for Russia while also seeking to manage tensions with Beijing. The US diplomat tomorrow is to meet China’s top brass in Beijing, where he is also expected to plead for restraint as Taiwan inaugurates president-elect William Lai (賴清德), and to raise US concerns on Chinese trade practices. However, Blinken is also seeking to stabilize ties, with tensions between the world’s two largest economies easing since his previous visit in June last year. At the
Nearly half of China’s major cities are suffering “moderate to severe” levels of subsidence, putting millions of people at risk of flooding, especially as sea levels rise, according to a study of nationwide satellite data released yesterday. The authors of the paper, published by the journal Science, found that 45 percent of China’s urban land was sinking faster than 3mm per year, with 16 percent at more than 10mm per year, driven not only by declining water tables, but also the sheer weight of the built environment. With China’s urban population already in excess of 900 million people, “even a small portion
UNSETTLING IMAGES: The scene took place in front of TV crews covering the Trump trial, with a CNN anchor calling it an ‘emotional and unbelievably disturbing moment’ A man who doused himself in an accelerant and set himself on fire outside the courthouse where former US president Donald Trump is on trial has died, police said yesterday. The New York City Police Department (NYPD) said the man was declared dead by staff at an area hospital. The man was in Collect Pond Park at about 1:30pm on Friday when he took out pamphlets espousing conspiracy theories, tossed them around, then doused himself in an accelerant and set himself on fire, officials and witnesses said. A large number of police officers were nearby when it happened. Some officers and bystanders rushed
Beijing is continuing to commit genocide and crimes against humanity against Uyghurs and other Muslim minorities in its western Xinjiang province, U.S. Secretary of State Antony Blinken said in a report published on Monday, ahead of his planned visit to China this week. The State Department’s annual human rights report, which documents abuses recorded all over the world during the previous calendar year, repeated language from previous years on the treatment of Muslims in Xinjiang, but the publication raises the issue ahead of delicate talks, including on the war in Ukraine and global trade, between the top U.S. diplomat and Chinese