In 2014, Amelia Quon and her team at NASA set out to build a helicopter capable of flying on Mars. Because Mars's atmosphere is only one percent as dense as Earth's, the air of Mars would not provide enough resistance to the rotating blades of a standard helicopter for the aircraft to stay aloft.For five years, Quon's team tested designs in a lab that mimicked Mars's atmospheric conditions. The craft the team ultimately designed can fly on Mars because its blades are longer and rotate faster than those of a helicopter of the same size built for Earth. According to the text,why would a helicopter built for Earth be unable to fly on Mars? A) Because Mars and Earth have different atmospheric conditions B) Because the blades of helicopters built for Earth are too large to work on Mars C) Because the gravity of Mars is much weaker than the gravity of Earth D) Because helicopters built for Earth are too small to handle the conditions on Mars

## Step 1<br />The problem is a comprehension question based on a given text. The text discusses the challenges of building a helicopter for Mars, due to the planet's unique atmospheric conditions. <br /><br />## Step 2<br />The text states that Mars's atmosphere is only one percent as dense as Earth's. This means that the air on Mars would not provide enough resistance to the rotating blades of a standard helicopter for the aircraft to stay aloft. <br /><br />## Step 3<br />The text also mentions that the team at NASA tested designs in a lab that mimicked Mars's atmospheric conditions. They found that the craft they ultimately designed could fly on Mars because its blades are longer and rotate faster than those of a helicopter of the same size built for Earth. <br /><br />## Step 4<br />Based on the information provided in the text, we can conclude that the reason a helicopter built for Earth would be unable to fly on Mars is because Mars and Earth have different atmospheric conditions.