Space Junk Everything seemed normal in space. Astronauts were working on a space station. Suddenly, Mission Control1 ordered them to leave the station. They rushed to the escape pod.2 Inside the pod, they waited for further orders. A small piece of space junk was speeding toward the space station at 28,000 kilometers (17,500 miles) per hour. The crew could be in danger! Ten minutes later, Mission Control sent an all-clear order. The station and crew were safe. Leftover Litter More than 1,600 pieces, large and small, became space junk. There are other kinds of space trash, too. Astronauts drop tools. They lose screws and drop gloves. Even chipped paint can become space junk. So can regular trash that's tossed from space stations. Small Scraps, Big Damage All this trash can cause problems. Litter that's orbiting Earth can travel at 7.7 kilometers (about 5 miles) per second. That's fast! No wonder space junk can crack windows, chip heat shields,3 and rip solar panels. Sometimes space junk falls to Earth. Friction with particles in Earth's atmosphere causes most junk to burn up. Really big pieces slam into the ground. Some splash into oceans. That's why scientists track space junk. They use radar and telescopes. These tools can track objects larger than a grapefruit. Millions of pieces are much smaller than this. These small pieces can do big damage. Yet there is no way to track them. Scientists are thinking of ways to clean up space. One way is to shoot lasers at space trash. The lasers would push the litter farther away. The only problem is Earth's gravity would eventually pull it back. It would become a problem again later. Here's another way. Make spacecrafts with giant nets. The nets would catch the litter. Then the litter could be dumped into Earth's atmosphere. The litter would burn up. Scientists still need to find other solutions. No doubt they will. Collecting space junk before it falls to Earth would most likely have a positive effect on the natural environment by
protecting space stations that orbit Earth from the junk keeping the junk from falling into Earth's habitats transforming space junk into useful materials permitting humans to leave junk in space
Question: Space Junk Everything seemed normal in space. Astronauts were working on a space station. Suddenly, Mission Control1 ordered them to leave the station. They rushed to the escape pod.2 Inside the pod, they waited for further orders. A small piece of space junk was speeding toward the space station at 28,000 kilometers (17,500 miles) per hour. The crew could be in danger! Ten minutes later, Mission Control sent an all-clear order. The station and crew were safe. Leftover Litter More than 1,600 pieces, large and small, became space junk. There are other kinds of space trash, too. Astronauts drop tools. They lose screws and drop gloves. Even chipped paint can become space junk. So can regular trash that's tossed from space stations. Small Scraps, Big Damage All this trash can cause problems. Litter that's orbiting Earth can travel at 7.7 kilometers (about 5 miles) per second. That's fast! No wonder space junk can crack windows, chip heat shields,3 and rip solar panels. Sometimes space junk falls to Earth. Friction with particles in Earth's atmosphere causes most junk to burn up. Really big pieces slam into the ground. Some splash into oceans. That's why scientists track space junk. They use radar and telescopes. These tools can track objects larger than a grapefruit. Millions of pieces are much smaller than this. These small pieces can do big damage. Yet there is no way to track them. Scientists are thinking of ways to clean up space. One way is to shoot lasers at space trash. The lasers would push the litter farther away. The only problem is Earth's gravity would eventually pull it back. It would become a problem again later. Here's another way. Make spacecrafts with giant nets. The nets would catch the litter. Then the litter could be dumped into Earth's atmosphere. The litter would burn up. Scientists still need to find other solutions. No doubt they will. Collecting space junk before it falls to Earth would most likely have a positive effect on the natural environment by
A. protecting space stations that orbit Earth from the junk
B. keeping the junk from falling into Earth's habitats
C. transforming space junk into useful materials
D. permitting humans to leave junk in space
Answer: