Please Can some one just put a highlight on the importent idea of this essay

please Can some one just put a highlight on the importent idea of this essay
I want to see if I cover all the idea or I missed importent one

this is the essay

There are 2,671 satellites and 90 space probes that orbit earth; each is prone to damage caused by the 8,500 scraps orbiting our planet. The junk travels at over 17,500 mph in space, so even the smallest debris can cause damage. For example, debris the size of a tennis ball can cause as much damage as about 25 sticks of dynamite. NASA replaced over 80 windshields on space shuttles so far. When building the entire shuttle costs 1.7 billion dollars, one can only imagine what repairs must cost. The money used for repairs could be used for research.
Environmental Effects
Not only does space junk create a safety issue, it is also an environmental risk. Most of the junk that falls to earth lands in water, which makes up roughly 2/3 of our planet’s surface. Letting debris from space fall in the ocean is just as damaging as dumping garbage. Toxic waste from the debris harms ocean life, which can eventually make its way through the food chain and poison our food or completely eliminate a species of marine life.
Most space junk is orbiting very high, and won't fall to earth for tens to hundreds of years. Although space junk does not pose immediate problems, junk will be falling as soon as the next decade. This could cause serious problems for future generations. By taking control of space debris, we are making our planet greener.
Human Danger
Twelve million pounds of space junk has survived re-entry into the Earth's atmosphere over the past 40 years, which, assuming the average car weighs 4,000 lbs, is the equivalent of 3,000 cars crashing down and polluting the earth. If so much debris has fallen to the earth, why is it that we don't see it more often?
The reason is that about 70 percent of the earth is comprised of water, making it far more likely for junk to land in the ocean and go unnoticed by the average person. How likely is it for space junk to hit and physically harm an individual? The Center for Orbital and Reentry Debris Studies states that 50 to 200 pieces of what is considered "large" debris plummet to Earth every year. There are, on average, 130 people per square mile of land that occupy the earth. However, researcher Alex de Sherbinin calculated that more than 99% of the earth’s land is not occupied at one given time.
Lottie Williams from Tulsa, Oklahoma, is currently the only person known to have been struck by space debris. She was hit on the shoulder by a small piece from the Delta rocket. Her injuries included minor burns and were not considered serious. The other major instance of space debris falling to earth occurred when a 500 pound steel tank from the Delta II satellite fell to earth in Texas. The falling tank missed a farmer's house by just 50 feet. Debris plummeting from space, while seemingly improbably, can be fatal. We can only assume that the increasing amount of debris will lead to more incidents and, ultimately, the premature deaths of many people worldwide.
Safety of Space Teams
The immediate danger of space junk is to the teams of astronauts exploring outer space. The amount of damage that results from a collision depends on the impact. The best-case scenario would be a small penetration, which is a low risk to the space team inside. In more severe cases, astronauts would have to evacuate their station immediately or risk being subject to the loss of oxygen and losing consciousness.
As more and more nations including India, China, the Koreas and others put satellites into space, the risk of collision can only increase. Measures are already being taken to control the growth of orbital debris. The United States has always required its astronauts to bag their wastes and return them to Earth. Extra shielding will also reduce the risk of damage. For example, 2,000 pounds of additional shielding is being considered for each of six space-station crew modules. Furthermore, the European Space Agency, an international consortium, is also looking into preventive measures.