The Asteroid 2011MD passing Earth today is quite exciting news for amateur astronomers, while its closest distance of 7,500 miles poses no threat to Earth's inhabitants.

Asteroids are not always so adorable and safe.

Since the formation of the earth, the planet has been hit by numerous asteroids and comets whose orbits bring them into the inner solar system. These objects known as NEOs (Near Earth Objects) still pose a danger to Earth today.

According to Pan-STARRS, there is strong scientific evidence that cosmic collisions have played a major role in the mass extinctions documented in Earth's fossil record.

For every thousand or so of those objects, there is one with an orbit crosses that of Earth, raising the possibility of a future collision, stated the website. In 1991 the U.S. Congress directed NASA to conduct workshops on how potentially threatening asteroids could be detected, and how they could be deflected or destroyed.

Our top representative of planet Earth, NASA, is getting ready to launch missions to investigate a possibly life-threatening asteroid.

NASA's upcoming robotic mission called OSIRIS-Rex (Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer) will be led by the University of Arizona.

An unmanned spacecraft will be launched in 2016, aimed at collecting samples from asteroid 1999 RQ36. The space rock is thought to be rich in the building blocks of life, and also carries the possibility of threatening Earth in the year 2182.

Budgeted for approximately $800 million, the mission aims to inject nitrogen into the asteroid and collect the dirt or gravel that gets stirred up. Anything collected by this inverse vacuum cleaner approach not only could give scientists a better idea about the odds of the asteroid striking Earth in 2170, currently at 1-in-1,800, but mights show organic- and water-rich material similar to what possibly seeded early Earth with the ingredients for life, according to

The spacecraft is scheduled to arrive at the asteroid by 2020, and bring samples back to Earth in 2023.

Besides collecting rock samples, plans for the 400 days spent near 1999 RQ36 include mapping the inside and outside of the asteroid and investigating the chemistry and mineralogy, according to Scientists hope to measure the so-called Yarkovsky effect, which describes how asteroids gain a gentle push from emitting thermal radiation from their night side.

The target asteroid, named 1999 RQ36 after the year it was discovered, measures 575 meters (one-third of a mile) in diameter. That's about the size of five football fields, which prevents it from spinning too fast when the spacecraft approaches. A large supply of loose dirt, or regolith on the surface of the asteroid would allow for easy sampling as well. The asteroid is a primitive B-class carbonaceous asteroid, likely to contain amino acids and other materials that serve as the building blocks of life on Earth. The key to the history of the solar system and the origin of life on Earth may lie in the upcoming close encounter with this asteroid.

While there are over 500,000 asteroids known, 1999 RQ36 is so far public enemy No.1 for space rock scientists, carrying the highest probability of impacting the Earth.

And yet the crisis goes together with an unprecedented opportunity when 1999 RQ36 serves as a time capsule from the early solar system to teach us how life began on our planet.

OSIRIS-REx will explore our past and help determine our destiny, said Dr. Michael Drake, Director of the University of Arizona's Lunar and Planetary Laboratory. It will return samples of pristine organic material that scientists think might have seeded the sterile early Earth with the building blocks that led to life. Such samples do not currently exist on Earth. OSIRIS-REx will also provide the knowledge that will guide humanity in deflecting any future asteroid that could collide with Earth, allowing humanity to avoid the fate of the dinosaurs.