NASA is planning an elaborate space mission by 2021 that will see a rocket zip out to an asteroid, capture it, and then bring it close to Earth. When it is safely in orbit near home, scientists can study it and thus plan Mars missions--as well as anti-collision systems if an asteroid impact threatens Earth.
NASA has set aside about $100 million for the plan in its next budget, and estimates the final cost will be less than the original figure of about $2.65 billion. Asteroid studies are important given the buzz about asteroid mining companies. Russia's near-miss with a meteor recently highlighted the importance of better understanding the composition of space rocks.