New radio images collected by a group of telescopes on Earth observed the direct impact of this volcanic activity on the moon’s thin atmosphere for the first time.
A study incorporating data collected from these images has been accepted for future publication in the Journal of Planetary Sciences.
Images captured by ALMA, or the Atacama Large Millimeter / submillimeter range of telescopes in Chile, provide a new perspective on the moon and its distinctive color palette of yellow, white, orange and red. These colors are caused by the sulfur gases emitted by many of the moon’s volcanoes that freeze when they meet the cold temperatures of the ice surface.
Although the idea of a volcanic moon hints at Io to be a hot celestial body, Io’s surface is always cold at minus 230 degrees Fahrenheit.
Io’s atmosphere is so dim that it is a billion times thinner than Earth’s. Previous observations and studies of the moon revealed that this atmosphere is largely composed of sulfur dioxide gas.
“However, it is not known what process drives the dynamics of Io’s atmosphere,” said study author Imke de Pater, professor of astronomy, earth and planetary sciences at the University of California, Berkeley, in a statement. Is it volcanic activity, or is it a gas rising (moved from a solid state to a gaseous state) from the ice surface when Io is in sunlight? “
Researchers used ALMA to take pictures of the moon as it moved in and out of Jupiter’s shadow to understand more about the moon’s atmosphere.
“When Io passes into the shadow of Jupiter, and it is out of direct sunlight, it is very cold for the sulfur dioxide gas, and it condenses on the surface of Io. During that time, we can only see sulfur dioxide from volcanic sources. So we can see exactly how “Much of the atmosphere is affected by volcanic activity,” Statia Losks Cook, co-author and astrophysicist at Columbia University, said in a statement.
The clarity of the ALMA images revealed distinct plumes of sulfur dioxide and sulfur monoxide from volcanoes, contributing 30% to 50% of the moon’s atmosphere. Scientists have also seen potassium chloride gas, a common component of magma, emerging from volcanoes. Researchers believe this indicates that magma reservoirs differ between volcanoes.
Io is slightly larger than our moon, but couldn’t be more different. Moreover, its environment is unlike anything found on Earth.
The moon, named for a dead woman who turned into a cow during a battle between Zeus and Hera in Greek mythology, has fountains of lava that can erupt to reach tens of miles.
Some Io volcanoes are so powerful that their eruptions can be seen with large telescopes on Earth.
The surface is also covered with lakes of molten silicate lava. With such a dramatic scene, it would be adventurous to fly near Io, but you wouldn’t want to live there.
Io is stuck between the enormous gravity of Jupiter and the pulling of orbits from other moons of the planet such as Europe and Ganymede, which contributes to activity on Io. Some volcanoes are huge, like Loki Patera, which is 124 miles wide.
The moon lies in a closed orbit around Jupiter, which means that the same side of the moon is always facing the planet.
Hot volcanoes on a cold moon
The ALMA images revealed that Io’s atmosphere becomes incredibly unstable as it passes through Jupiter’s massive shadow. This happens every 42 hours during Io’s orbit around Jupiter.
During these “eclipses,” Io’s sulfur dioxide is reduced, indicating that the moon’s lower atmosphere is collapsing and freezing at the surface. But when Io emerges from Jupiter’s shadow and receives sunlight, the gas returns.
“Once Io gets into the sunlight, the temperature increases, this (sulfur dioxide) ice leaches into the gas, and it repairs the atmosphere in about 10 minutes, faster than the models predicted,” said de Pater. .
But the researchers’ data showed that not all of the sulfur dioxide gas freezes during the temperature drop that Io experiences while in Jupiter’s shadow. In fact, ALMA was able to detect global radio emissions of sulfur dioxide from what researchers call phantom volcanoes, which do not emit smoke or detect particles, but rather release gas into the atmosphere that is warm enough to prevent it from condensing and freezing.
How do these hot processes unfold on such a cold moon? The locomotive of Jupiter, Ganymede, and Europe heats the interior of Io, creating volcanoes that release hot sulfur dioxide gas.
Finally, the gas condenses and solidifies in a thick layer of sulfur dioxide ice on the surface of Io. This layer is covered in volcanic dust, which creates the distinctive Io Colors.
“By studying the atmosphere of Io and volcanic activity, we learn more not only about the volcanoes themselves, but also about the process of tidal heating and the interior of Io,” said Luszcz-Cook.
Future observations and studies will allow the researchers to determine the temperature of the ion’s lower atmosphere, which remains unknown until now.