Scientists may have discovered large amounts of water hidden deep beneath the surface of Jupiter's famous Great Red Spot. The discovery, which was made using ground-based telescopes, opens up the possibility that extremophile lifeforms could exist in the atmosphere of the enigmatic gas giant.
Jupiter is one of the most visually striking and scientifically fascinating planets in our solar system. It is twice as massive as all of the other planets in our solar system combined, and its surface plays host to mindbogglingly epic storms that have been known to rage for over a hundred years.
Whilst Earth-based observatories, orbital telescopes and unmanned probes such as NASA's Juno spacecraft have greatly expanded our knowledge of Jupiter, the gas giant still harbors many secrets.
One of the long-standing mysteries surrounding Jupiter regards the amount of water contained in its hydrogen and helium dominated atmosphere. Jupiter's eclectic family of 79 moons are predominantly made up of ice, and so it would make sense for the planet itself to contain significant amounts of water.
Discovering significant amounts of water in Jupiter's gaseous atmosphere would help scientists understand the dynamic, turbulent nature of the planetary giant, as well providing insights into the formation of our solar system. On Earth, water is thought to have played a major factor in the emergence of life, and serves as the driving force for numerous critical atmospheric processes.
Scientists believe that water could fulfill the same role as a key atmospheric driver on Jupiter, albeit on a far greater scale. Furthermore, where there is water, there is the potential for life. Extremophiles have been discovered living in some of the most hostile environments known to exist on Earth. Whilst the emergence of life in Jupiter's atmospheric clouds is difficult to imagine, it can't be ruled out.
Finally, scientists cannot say for sure what lies at the planet's heart. However, the discovery of significant amounts of water molecules residing deep within the atmosphere would suggest that the gas giant boasts a rocky, icy core, rather than a core comprised of a dense soup of super-hot material.
Scientists had previously attempted to estimate the amount of water hidden within the Jovian atmosphere by directing a probe to plunge into its surface. On December 7, 1995, NASA's Galileo probe entered Jupiter, and transmitted a full 58 minutes of data before finally being crushed by extreme atmospheric pressures.
It was discovered that the region in which Galileo had taken the dive was much drier than expected. A satisfactory answer to the water question continued to elude planetary scientists, but new research is changing that.
In a new study published in the Astronomical Journal, scientists peered into the eye of Jupiter's Great Red Spot in an attempt to find the elusive atmospheric water. The Great Red Spot is a colossal storm twice the size of our planet that has been raging for about 150 Earth years.
The team searched for thermal, or infrared radiation escaping the spot from deep within the planet's interior. The raw data was captured by instruments mounted on two observatories located on the summit of Maunakea, Hawaii – NASA's Infrared Telescope Facility and the Keck 2 telescope. The raw data was then analyzed using specially designed software.
The data showed that Jupiter's atmosphere was divided into three distinct cloud layers. Since Jupiter does not have an identifiable surface, its impossible to give an altitude for each of the layers relative to the ground as we can for the layers of Earth's atmosphere. Instead, Jupiter's atmospheric depth is measured in bars – one bar being equivalent to Earth's atmosphere at sea level. The deeper into Jupiter's atmosphere you go, the greater the pressure.
Experts believe that the uppermost cloud layer is comprised of ammonia, the middle of ammonia and sulphur, and the bottom liquid and water ice. In line with this model, the team discovered the chemical signature of water at a depth of 5 - 7 bars, or roughly 100 miles below the surface.
This corresponds to the point just above the deepest of the three cloud layers where scientists believe the gas giant's interior temperature drops to the freezing point for water. The results also indicate that Jupiter's atmosphere contains 2 – 9 times as much oxygen as the Sun.
One of the benefits of the new technique is that it relies solely on ground-based observations. Similar studies could therefore be made of the other gas giants that populate our solar system – Saturn, Uranus, and Neptune - without the need to spend money and time launching spacecraft to make in situ measurements of their atmospheres.
Moving forward, the team hopes to compare its data with that collected by the Juno spacecraft, which is currently searching for water in Jupiter's atmosphere using its own infrared spectrometer. If the ground-based observations are corroborated by the Juno data, the researchers will be confident in examining the rest of Jupiter's atmosphere.
A paper detailing the findings has been published in the Astronomical Journal.
Scroll down to watch a video zooming in on Jupiter's Great Red Spot.
Source: NASA, Clemson University