In the dim sky of Jupiter’s moon GanymedeAstronomers, the largest satellite in the solar system, have detected evidence of water vapor for the first time, new research has found.
This discovery could shed light on similar watery atmospheres that may envelop other icy objects. Solar system Beyond that, the researchers said.
According to previous research, Ganymede is larger and only slightly smaller than Mercury and Pluto. Mars — May contain more water than all the oceans on Earth combined. However, the moon on Jupiter is so cold that the water on its surface is frozen hard. Ganymede’s liquid water lurks about 100 miles (160 km) below the crust.
Previous studies have suggested that the ice on the surface of Ganymede can change directly from solid to gas, leaving it in the form of a liquid and allowing water vapor to form part of the giant lunar thin atmosphere. rice field. But this water proof has proven to be elusive — until now.
In a new study, researchers analyzed old and new data from NASA’s Ganymede. Hubble Space Telescope.. In 1998, Hubble captured the first UV image of Ganymede. This includes photos of the aurora, a giant moon version of the light north and south of the Earth. The colorful ribbons of charged gas in these aurora helped to provide evidence that Ganymede has a weak magnetic field.
The UV signals detected in these aurora bands suggested the presence of oxygen molecules, each made up of two oxygen atoms, generated when charged particles erode the ice surface of Ganimede. However, some of these UV radiation did not match what was expected from the atmosphere of pure molecular oxygen. Previous studies have suggested that these discrepancies are related to atomic oxygen, a signal from a single oxygen atom.
As part of a large observation program to support NASA Junho Mission JupiterResearchers have tried to use Hubble to measure the amount of atomic oxygen in Ganymede’s atmosphere. Unexpectedly, they found that there was very little atomic oxygen there. This suggests that there must be another explanation for the early UV signal.
Scientists have shown how high the surface temperature of Ganimede is throughout the day at the lowest temperature of about minus 190 degrees Fahrenheit (minus 123 degrees Celsius) at noon and about minus 315 degrees Fahrenheit (193 degrees Celsius) at night. I paid attention to whether it would change. .. In the hottest areas of Ganymede, the ice can get warm enough and turn directly into steam. They said that the differences seen between many UV images from Ganymede are in close agreement with the expected location of the lunar atmospheric water based on climate.
“Atmospheric water vapor is in very good agreement with the data,” Lorenz Roth, a planetary scientist and lead author of research at the KTH Royal Institute of Technology in Stockholm, told Space.com.
The main reason why Ganymede’s atmospheric water could not be detected in previous studies is that the UV signal from molecular oxygen is so strong. “It’s hard to find another signal in this stronger oxygen signal,” Ross said.
“These findings suggest that water vapor actually exists in the atmosphere of ice bodies outside the solar system,” Ross said. “Now we may see it in more places.”
Detailed scientist Their discovery Journal Nature Astronomy Online Monday (July 26).
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Water vapor was detected for the first time on the giant Jupiter moon Ganymede
Source link Water vapor was detected for the first time on the giant Jupiter moon Ganymede