New radio images of the Jovian moon have finally provided some answers to long-standing questions about its atmosphere.
Io is the most volcanic spot in the solar system. More than 400 active volcanoes span its surface, an expression of the internal stress of the moon as it is seen in different directions by gravity, not only by Jupiter but also by the planet’s other three galillion moons.
Io’s thin atmosphere and surface are dominated by sulfur dioxide – yes, brimstone – carved from the interior. It exits as a gas through volcanic partitions and maws and freezes on the ground at night as it cools, causing the moon to turn its sick yellow and orange.
But just how much of that gas comes directly from volcanoes, versus how hot is the surface of sulfur dioxide in sunlight? It has been difficult to determine.
“It was not known which process governs the dynamics in the atmosphere of Io,” said astronomer Imke de Pater of the University of California, Berkeley.
“Is it volcanic activity, or gas that is submerged by the icy surface when Io is in sunlight? What we show is, in fact, that volcanoes have a big impact on the atmosphere.”
Researchers finally have some answers, and are simultaneously able to detect the amount of volcanic sulfur dioxide on the Moon.
– Roman Taxhenko (@_RomanTkachenko) 10 April 2018
For a world that is constantly leaking volcanic gas, Io’s atmosphere is surprisingly thin; Most of that gas escapes through a complex contact with Jupiter and its magnetic field at a rate of about 1 metric ton per second, which contributes to a giant donut of plasma, called the Io plasma torus that is Jupiter Revolves around
The rest of the atmosphere can reveal a lot about geological processes in the interior of the Moon, which in turn can help us understand some of the dynamics of planets beyond our solar system.
If we know precisely the effects of competitive gravity effects on IO, and why those effects do not have the same effect on other bodies, then we can make more educated conclusions about how gravity affects them.
Therefore, astronomers used the Atacama Large Millimeter / Submillimeter Array (ALMA) in Chile to take a closer look at Io under the radio wavelength as it moves in and out of Jupiter’s shadow – the Jovian eclipse.
The first thing they found is that sulfur dioxide does not remain in the atmosphere of Ayo. At night, the temperature drops below the freezing point of sulfur dioxide.
When this surface re-circulates in broad daylight, the frozen sulfur dioxide returns to the atmosphere, refilling it in about 10 minutes – faster than expected.
This strangely bizarre volcano became the perfect tool to study atmospheric contributions.
Columbia University astronomer Statia Lusz-Cook reported, “When the ion passes into Jupiter’s shadow, and comes out of direct sunlight, it is too cold for sulfur dioxide gas, and it condenses on the surface of the ion is.”
“During that time we can only see sulfur dioxide volcanically. So we can see how much of the atmosphere is affected by volcanic activity.”
In ALMA images, the team was able to clearly identify, for the first time, evidence of streams of sulfur dioxide and sulfur monoxide emanating from volcanic sources.
In the volcanic fields with sulfur dioxide or monoxide, they saw something else – potassium chloride, another volcanic gas.
This suggests that different volcanoes are tapping into different magma reservoirs, rather than sharing them. This suggests some interesting complexity beneath the surface of the IO.
From their images, the team was able to calculate the volcanic contribution to Io’s atmosphere. About 30 to 50 percent of sulfur dioxide comes directly from volcanoes.
Obviously future work will help narrow that down. The team says that the next step in their research is trying to take the temperature of the atmosphere at Ayo, especially at low altitudes. This will be more challenging, but not impossible.
“In order to measure the temperature of the atmosphere of Ayo, we need to get a higher resolution in our observations, which requires us to observe the Moon longer. We can only do this when Io sunlight Happens in, because it doesn’t spend. A lot of time in the eclipse, “said Day Pater.
“During such an observation, the Io will rotate to tens of degrees. We will need to implement software that helps us create random images. We did this first with Jupiter’s radio built with Alma and Very Large Array. Done with pictures. ”
The research is available in two papers, published in one The Planetary Science Journal, And in press with another The Planetary Science Journal And uploaded to arXiv.