Scientists are considering the possibility of sending humans to Mars in the coming decades. Although there have been successful manned missions to the Moon in the 1960s and 1970s, Mars is 150 times further away from Earth than the Moon is. Thus the project of sending humans to Mars would require solving an array of problems the Moon missions did not have to face.
One problem is that a round-trip to Marsand back is likely to take at least two years. The trip to the Moon lasted only a few days, and it was easy to bring enough supplies of food, water, and oxygen; but the cargo capacity of space vehicles is too limited to put on board the food, water, and oxygen required by a crew for a period of two years. Without those essentials, though, a Mars mission is impossible.
A second problem is that astronauts on the Mars mission would be in the zero-gravity environment of space for many months at a time. Spending a long time in the zero-gravity environment has negative effects on the human body, such as decreased muscle mass and lower bone density. Over the course of a two-year mission, the effects would be so severe, they would make it impossible for humans to make the trip without experiencing grave medical problems
Finally, astronauts on a mission to Mars would be exposed to dangerous levels of space radiation, much of which comes in the form of charged particles emitted by the Sun. Earth's magnetic field, which normally protects us from dangerous solar radiation, would not be able to protect a spaceship traveling in interplanetary space. Constructing a shield that would protect the whole spaceship from space radiation is at present impossible because if would add too much weight to the ship.
The lecturer explained three different solutions to overcome the problems encountered in Mars mission
First, author mentioned the limitation of space vehicle to carry as much as food and water for a round trip of two years. The lecture thinks that it can be solved by hydroponic, which is a technique of growing plants in water rather than the soil. As hydroponics needs little space it can be easily cultivated in a spacecraft. Also she mentioned that as all plants inhale carbon dioxide and exhale oxygen,scientist in the space ship can get fresh air. She added to the point that hydroponic technology can recycle water, thus the problem of scarcity of fresh water can also be solved.
Second, the heath problems including loosing muscle mass and lower bone density due to low gravity can be easily resolved by regular exercise and vitamin and nutrient supplements.
Third, professor argues that sun radiation are not always harmful. He points out the fact that it is possible to make a small shield or shelter which can easily give protection during the time of sun's harmful radiation. It is also possible to keep certain radar instruments which can alarm when sun radiates dangerous rays.
All in all, professor clearly explained three methods to recover from the dangers of Mars expedition.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2020-01-20 | f.jafary66@gmail.com | 80 | view |
| 2020-01-18 | naziii | 3 | view |
| 2020-01-07 | 3dra | 3 | view |
| 2019-12-27 | Amirreza97 | 3 | view |
| 2019-12-16 | jeffhjz | 3 | view |
- Do you agree or disagree with the following statement?To improve the quality of education, universities should spend money on salaries university professors.Use specific reasons and examples to support your answer. 76
- Did bees (a type of insect) exist on Earth as early as 200 million years ago? Such a theory is supported by the discovery of very old fossil structures that resemble bee nests. The structures have been found inside 200- million-year-old fossilized trees i 83
- Pterosaurs were an ancient group of winged reptiles that lived alongside the dinosaurs. Many pterosaurs were very large, some as large as a giraffe and with a wingspan of over 12 meters. Paleontologists have long wondered whether large pterosaurs were cap 73
- One of the main problems with the internal-combustion engine is that it relies on petroleum, either in the form of gasoline or diesel fuel. Petroleum is a finite resource; someday, we will run out of oil. The hydrogen needed for fuel-cell engines cannot e 76
- Burning coal in power plants produces a waste product called coal ash, a material that contains small amounts of potentially harmful chemicals. Environmentalists in the United States are concerned about the damage such harmful chemicals may be doing to th 80
Grammar and spelling errors:
Line 2, column 56, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...entioned the limitation of space vehicle to carry as much as food and water for a...
^^
Line 2, column 250, Rule ID: SENTENCE_FRAGMENT[1]
Message: “As” at the beginning of a sentence requires a 2nd clause. Maybe a comma, question or exclamation mark is missing, or the sentence is incomplete and should be joined with the following sentence.
...g plants in water rather than the soil. As hydroponics needs little space it can b...
^^
Line 2, column 329, Rule ID: SENT_START_CONJUNCTIVE_LINKING_ADVERB_COMMA[1]
Message: Did you forget a comma after a conjunctive/linking adverb?
Suggestion: Also,
...n be easily cultivated in a spacecraft. Also she mentioned that as all plants inhale...
^^^^
Line 2, column 406, Rule ID: COMMA_PARENTHESIS_WHITESPACE
Message: Put a space after the comma
Suggestion: , scientist
... inhale carbon dioxide and exhale oxygen,scientist in the space ship can get fresh air. Sh...
^^^^^^^^^^
Line 2, column 481, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...t fresh air. She added to the point that hydroponic technology can recycle water,...
^^
Line 2, column 561, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...r, thus the problem of scarcity of fresh water can also be solved. Second, the h...
^^
Line 4, column 283, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...keep certain radar instruments which can alarm when sun radiates dangerous rays. ...
^^
Transition Words or Phrases used:
also, first, if, second, so, third, thus
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 8.0 10.4613686534 76% => OK
Auxiliary verbs: 8.0 5.04856512141 158% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 9.0 12.0772626932 75% => More relative clauses wanted.
Pronoun: 12.0 22.412803532 54% => OK
Preposition: 25.0 30.3222958057 82% => OK
Nominalization: 5.0 5.01324503311 100% => OK
Performance on vocabulary words:
No of characters: 1085.0 1373.03311258 79% => OK
No of words: 216.0 270.72406181 80% => More content wanted.
Chars per words: 5.02314814815 5.08290768461 99% => OK
Fourth root words length: 3.83365862548 4.04702891845 95% => OK
Word Length SD: 2.66402502259 2.5805825403 103% => OK
Unique words: 137.0 145.348785872 94% => More unique words wanted.
Unique words percentage: 0.634259259259 0.540411800872 117% => OK
syllable_count: 332.1 419.366225166 79% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 3.0 8.23620309051 36% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 0.0 2.5761589404 0% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 10.0 13.0662251656 77% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 21.0 21.2450331126 99% => OK
Sentence length SD: 45.0439785099 49.2860985944 91% => OK
Chars per sentence: 108.5 110.228320801 98% => OK
Words per sentence: 21.6 21.698381199 100% => OK
Discourse Markers: 4.0 7.06452816374 57% => More transition words/phrases wanted.
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 7.0 4.19205298013 167% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 0.0 4.27373068433 0% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.0669012179483 0.272083759551 25% => The similarity between the topic and the content is low.
Sentence topic coherence: 0.0264234657307 0.0996497079465 27% => Sentence topic similarity is low.
Sentence topic coherence SD: 0.0240360518034 0.0662205650399 36% => Sentences are similar to each other.
Paragraph topic coherence: 0.0458388552895 0.162205337803 28% => Maybe some paragraphs are off the topic.
Paragraph topic coherence SD: 0.0336418166476 0.0443174109184 76% => OK
Essay readability:
automated_readability_index: 13.0 13.3589403974 97% => OK
flesch_reading_ease: 58.62 53.8541721854 109% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 11.84 12.2367328918 97% => OK
dale_chall_readability_score: 9.21 8.42419426049 109% => OK
difficult_words: 62.0 63.6247240618 97% => OK
linsear_write_formula: 11.5 10.7273730684 107% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
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It is not exactly right on the topic in the view of e-grader. Maybe there is a wrong essay topic.
Rates: 3.33333333333 out of 100
Scores by essay e-grader: 1.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.