The impact of Comet Shumaker Levi 9 in Jupiter

In July 1994, one of the most dramatic events of a collision between two bodies in the solar system took place. Here in one article, news from that time describing the aftermath *Collection of real-time reports in the press of the year 1994

To the preliminary article by Prof. Akiva Bar-Nun published in Galileo two weeks before the event

Tzafir Rinat, Haaretz, writes on 17/7/1994 that the scientists were able to predict quite accurately what happened during the collision of the comet fragments with Jupiter. They were less successful in clarifying what was happening to the general public

The first fragment of Comet Shoemaker-Levy 9 smashed past Jupiter yesterday at 22:15 Israel time - this is what an astronomer at the Sutherland Observatory in South Africa said. The intensity of the collision was small, and it seems that the comet fragment was swallowed by Jupiter's atmosphere. It should be noted that the first of the 21 fragments of the comet was expected to smash into the surface of Jupiter in an hour. 21:54 Astronomers from all over the world were waiting last night for a collision between the comet and Jupiter. The comet moves towards Jupiter at a speed of 60 kilometers per second. It is made up of 20 fragments, and most scientists expected their collision with Jupiter to produce an explosion more powerful than any nuclear weapon on Earth. Other scientists dismissed this hypothesis, arguing that the force of the collision would be smaller. The series of clashes will continue until July 22, and its peak should be this Wednesday. Astronomers will mainly monitor the aftereffects of the explosion, since it will occur on the dark side of Jupiter and it will be impossible to distinguish it from Earth. This is the first time that scientists will be able to track a collision between a comet and a star, and not just the scars left by the comet on the star.

In Israel, the comet is being monitored from the Florence and George Wise Observatory of Tel Aviv University, located at the Ramon Observatory. The observation is carried out by Prof. Elia Leibovitz, director of the observatory, Dr. Noah Brosh and Prof. Yuri Meckler from the Department of Geophysics and Planetary Sciences at Tel Aviv University and the American astronomer D. Jim Scotti of the University of Arizona. Scotti scientifically confirmed a year ago the discovery of the comet by astronomers Eugene and Carolyn Shoemaker and David Levy. The scientists in Israel and around the world will be able to follow Jupiter until the hour, 24:30 when the star sets. According to Prof. Leibovitz, it is not clear what the impact of the collision will be on Jupiter, or to what extent it will be possible to see the explosion. Astronomers also do not know for sure what the size of the comet's parts is.

18/7/94

Spots were observed on the surface of the planet Jupiter after the impact of a comet

In the areas on the surface of Jupiter, where a comet hit, several dark spots were discovered. This is what Yigal Fatal, director of the observatory in Givatayim, said yesterday. Fatal said that in the observations conducted, three spots were seen in the southern latitude of Jupiter, in the area where the impact was predicted. The spots were larger and darker than those predicted by the collision simulations. It was possible to see the spots with a telescope, without the help of additional equipment. Additional spots were seen in the northern region of Jupiter, but it is not clear if they were created by the collision. It will be possible to know about this only after analyzing the findings of the observations. These spots have never been seen on the surface of Jupiter.

A fragment from Comet Shoemaker-Levy 9 hit Jupiter with a force of 250 million megatons

19/7/94

A fragment of Comet Shoemaker-Levy 9 hit Jupiter yesterday, with a force of 250 million megatons. The force of the impact nearly disabled one of the largest telescopes on Earth. It was the largest rupture to hit Jupiter so far.

"This is a tremendous blow," said one of the two discoverers of the comet, Eugene Shoemaker. He spoke at a press conference where he referred to the collision between the comet's fragment, called @ G, and Jupiter. The collision happened yesterday at 10:30 The remnants of the explosion were so bright that they almost put out of use the Kick telescope, which is located on Mauna Kaa in Hawaii. According to the astronomers, the brightness of the remains was the same as that of the star Jupiter as it is normally seen through the lens of the telescope. Shoemaker estimated that the energy released following the explosion was equal to 250 million megatons.

Eugene Shoemaker pointed out that the temperature generated during the collision may reach tens of thousands of temperatures. He added that if one of the fragments had hit the Earth, it would have caused the greatest natural disaster known to mankind.

Professor Ilya Leibovitz, director of the observatory at Mitzpe Ramon, said that in the reports that arrived last night, it was stated that after one of the impacts of the comet fragments, one of the moons of Jupiter vaporized for seven minutes, which apparently indicates that a large amount of dust covered that moon following the impact of the fragment. According to Leibovitz, it is still possible to see the signs left by the impact of the first comet fragment, which occurred on Saturday night. He noted that all the comet fragments landed at the same latitude, south of Jupiter's equator.

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After the great collision

31/7/00
By Tzafrir Rinat, Haaretz

The scientists were able to predict quite accurately what happened during the collision of the comet fragments with Jupiter. They were less successful in clarifying what was happening to the general public

The series of collisions between the fragments of comet Shoemaker-Levy 9 and Jupiter matched the predictions of the scientists, who predicted their intensity with great accuracy. Although they occurred on the far side of Jupiter, they also allowed scientists to take a series of photographs that clearly showed the effects of the collisions on Jupiter's atmosphere.

But although the scientists collected a lot of information during the observations of the series of collisions, the science section of "The Economist" pointed out that in the meantime they did not collect much information about Jupiter or the comet. They are still waiting for information to arrive from spacecraft and telescopes and are still engaged in analyzing the information they already have.

The light that helped in obtaining the impressive images of the results of the collisions also carries information about the composition and temperature of the gases in the collision regions. In these areas there is currently material from different layers of Jupiter's atmosphere and the remains of the comet, and only in later stages will scientists be able to know what the different components of the gaseous material are. The scientists are disappointed that the comet fragments did not penetrate deeper into Jupiter's atmosphere, because if it had, they would have been able to get more information about the different layers of this atmosphere. Most of the comet fragments collided in the upper layers of the atmosphere.

Prof. Yuri Meckler from the Department of Geophysics and Planetary Sciences at Tel Aviv University points out that following the collisions, scientists did not learn anything new about Jupiter's atmosphere. "It will take some time before they analyze the information. We hope to learn about the dynamics of Jupiter's atmosphere and the meteorology of this atmosphere. We are also interested in the composition of the clouds in the atmosphere. We know they exist but not what they are made of." The most powerful collision in Jupiter was supposed to be the rupture, Q1, but to the surprise of the scientists it almost did not leave its mark on Jupiter's atmosphere.

A few hours after the fragment collided with the atmosphere, the dark scar left by the collision disappeared. British astronomers believe that this fraction was smaller than initially thought. Another possibility is that the fragment was less stable than the other fragments and it began to disintegrate even before entering the atmosphere. In 1995, the Galileo spacecraft will enter the atmosphere of Jupiter and descend slowly with the help of a parachute. During the descent, the spacecraft will check the composition of the atmosphere and transmit its findings to Earth. Maybe then the scientists will also be able to know more about the effect that the Shoemaker-Levy impact had on the atmosphere.

And if the scientists made many achievements in accurately predicting how Shoemaker-Levy would harm justice and monitoring the harm, they were less successful in explaining what was happening in justice to the world public, who followed Shoemaker-Levy's moves with great interest. The public did not have clear information on almost all the basic data related to the collision. Many people believed, for example, that the collision might have a direct impact on Earth, potentially causing damage, even though Jupiter is a huge distance from Earth. Many also believed that it would be possible to see the collisions with the naked eye or with the help of simple optical devices, as they saw last year the meteor shower created by the comet Swift-Tuttle that passed near the Earth. However, the collisions with Jupiter, or rather, their results, could only be seen with the help of sophisticated amateur telescopes or telescopes in observatories and research institutes.

Ambiguity also arose regarding the collision itself. Many believed that the comet would collide with a solid star, but the collision was in the atmosphere of a star composed mostly of gases and liquids. Jupiter itself is defined as a planet. In an article he recently published in "Galileo" magazine, Prof. Akiva Ben Nun from the Comet Research Laboratory at Tel Aviv University wrote: "A star, unlike a planet, shines because it radiates nuclear energy. Nine planets circle around our sun, much smaller than it, so the temperature in their center is not enough to ignite nuclear combustion. They appear to us to shine only because of the sunlight that hits them and is returned to us. They are called planets and not planets, since planets are not stars."

The main failure of the scientists was in explaining the importance of tracking the collision between the comet and Jupiter. The immediate focus on the collision has led many to the conclusion that scientists are primarily interested in its immediate consequences. But the scientists are mostly interested in the long-term consequences of the collision and a better understanding of comets and Jupiter.

Another reason for the interest in the collision is the enormous importance that comets have in the formation of life on Earth. Some scientists believe that it was the comets that brought the elements of life to Earth. "The impact of comets consisting mainly of water, iron, silicates and organic substances (made up of carbon, nitrogen, oxygen and hydrogen compounds)", Ben Nun wrote in "Galileo", "brought these substances to the earthly planets, including the Earth. These compounds were broken down in the Earth's atmosphere about four billion years ago by solar radiation, lightning and thunder. The new substances that were created from them melted in the oceans on the surface of the ancient earth and created the components of life: amino acids, the components of proteins, the components of sugars, and the components of nucleic acids." Against this background, according to Ben Noon, it is clear why scientists are interested in the Shoemaker-Levy vulnerability: "They are actually reconstructing what happened on the surface of the ancient Earth."

Comets were also very important in the further development of life on Earth. The scientists speculate that an impact by a giant comet 65 million years ago brought huge amounts of dust into the earth's atmosphere, which greatly reduced the amount of sunlight reaching the ground. This led to a sharp decrease in the amount of plants that need sunlight to carry out photosynthesis, and subsequently to the disappearance of the plant-eating dinosaurs. The scientists' hypothesis is based on finding a large amount of the element iridium, which originates from meteoric dust created by comets, in a geological layer that is 65 million years old. The disappearance of the dinosaurs made possible the culture of mammals and the appearance of man.

Recently, British scientists put forward the hypothesis that the impact of a large comet fragment on the Earth in the sixth century AD led to changes in the atmosphere, resulting in damage to the food supply and severe epidemics that shocked ancient civilizations such as China and Byzantium.

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