Comet: Source of Mysterious Water on Jupiter

A composite Cassini image of Jupiter. The dark spot is the shadow of Europa. The Great Red Spot, a persistent anticyclonic storm, is at lower right. White atmospheric bands, termed zones, represent areas of upwelling; reddish bands, called belts, represent areas of downwelling. They display high-altitude ammonia ice clouds and lower clouds of unknown composition, respectively.

(Image Source: )

European Scientists Discover Source of Jupiter's Mysterious Water

By Eve Pearce, European Correspondent

Reporting for SpaceWatchtower

2013 May 4

The European Space Agency (ESA) has announced that the source of the mysterious water in Jupiter's upper atmosphere was the comet Shoemaker-Levy 9, which collided with the planet in July 1994.

The presence of the water had left scientists baffled for many years. However, they now understand that it was delivered when, during the catastrophic collision, a series of 21 fragments of the comet was dispersed into the planet's southern hemisphere. They left many dark scars on Jupiter's atmosphere for several weeks after the impact.

First extra terrestrial collision  

The significant impact of Shoemaker-Levy 9 was noted as the first direct observation of an extra terrestrial collision with a planet in our solar system. The force of the impact was so great that many astronomers were able to monitor and follow it with their ground-based telescopes. However, it was not until a year after the impact that the ESA's Infrared Space Observatory (ISO) was launched. The spacecraft then discovered the concentration of water in the atmosphere . 

The scientists at the ISO subsequently set out to study the newly found water, and went on to establish that its origin was not the planet itself. They suspected that it could have been delivered by the impact of Shoemaker-Levy 9, but they lacked any evidence to prove this theory to be correct.

More water found in southern hemisphere 

After more than 15 years of intense study, the ESA's Herschel spacecraft used its sensitive infrared vision to identify vertical and horizontal distribution of the water's chemicals. It was found that there was at least two - perhaps even three - times more water in the planet's southern hemisphere than in its northern hemisphere. 

In a statement, researcher Thibault Cavalié from the Laboratoire d’Astrophysique de Bordeaux in France, said: “Only Herschel was able to provide the sensitive spectral imaging needed to find the missing link between Jupiter’s water and the 1994 impact of comet Shoemaker-Levy 9. According to our models, as much as 95 percent of the water in the stratosphere is due to the comet impact.”

Major scientific breakthrough

The discovery is a huge breakthrough for scientists, who had explored several other possibilities as being the source of the water. At one point, they thought it could have been delivered by one of Jupiter's ice moons via giant vapour torus. Another theory was that it was from the rain of interplanetary dust particles. However, both of these theories were eventually ruled out, leaving the Shoemaker-Levy 9 collision the only other viable cause. 

Momentous event in science 

The force of the impact back in 1994 was so great that many would-be scientists were able to witness it using standard telescopes. When it was announced that there was going to be a collision, many people camped outside armed with their most powerful telescopes for a chance of witnessing it. At the time, there were several space camps - both professional and amateur - at which both scientists and enthusiasts alike camped out in various motorhomes and tents to collectively witness the collision, which happened during the night. Since then, the mystery and intrigue surrounding Jupiter has led to the formation of many enthusiast clubs and camps. Those wishing to bring a motorhome to an astronomy event would have had to seek out adequate - even specialist - motorhome insurance as they typically involve a fair amount of traveling and moving around at a moment's notice depending on where the conditions for space watching are at their best. That said, these vehicles in 1994 and in the future have proven to be good ways to go to astronomy camps in comfort, while protecting equipment for momentous occasions. 

An indication of future studies

The next Jupiter mystery to be solved is likely to revolve around the planet's moons. For years, scientists have remained puzzled by the moons. The ESA has hinted that its recent study into the cause of the planet's water is an indication of what is to come from its future studies; the Jupiter Icy Moons Explorer Mission, scheduled for launch in 2022, will set out to further understand Jupiter's atmospheric ingredients. 

The exciting discovery by the ESA is sure to fuel further intrigue and interest in the solar system's largest planet. However, it does put much of the planet's current mystery to rest. Göran Pilbratt, Herschel project scientist from the ESA said that his team's observations have “finally solved a mystery that has been open for nearly two decades.”

Source: Eve Pearce, European Correspondent Reporting for SpaceWatchtower, a project of Friends of the Zeiss.


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