Asteroids are the best real estate in the Solar System.

Despite their celestial age, our understanding of asteroids is still in its infancy. However, the more we learn about them, the more enticing destinations they become.

Asteroids are primordial material left over from the formation of the Solar System. They are scattered throughout it: some pass close to the Sun, and others are found out beyond the orbit of Neptune. A vast majority have been collected by JupiterGÇÖs gravity into a belt between it and Mars GÇô an area known as the Main Belt. As it turns out, we have been discovering thousands of asteroids that do not belong to the Main Belt, but instead pass near EarthGÇÖs orbit GÇô nearly 9,000 to date, with almost a thousand more discovered every year.

Many of these near-Earth asteroids are easily accessible from Earth. And many contain enormous quantities of accessible resources.

AN INCREDIBLE RESOURCE
There are over 1,500 asteroids that are as easy to get to as the surface of the Moon. They are also in Earth-like orbits with small gravity fields, making them easier to approach and depart.

Asteroid resources have some unique characteristics that make them especially attractive. Unlike Earth, where heavier metals are close to the core, metals in asteroids are distributed throughout their body, making them easier to extract.

Asteroids contain valuable and useful materials like iron, nickel, water, and rare platinum group metals, often in significantly higher concentration than found in mines on Earth.

We are only just beginning to realize the incredible potential of asteroids. The first encounter of a spacecraft to an asteroid was 1991, as the Galileo flew by the 951 Gaspra asteroid on its way to Jupiter. Our knowledge of these celestial neighbors has been revolutionized by a small set of US and international missions carried out since that time. With each visit or fly-by, the science on asteroids has been rewritten.

Target Asteroids

Planetary Resources will likely visit a wide range of asteroids with a variety of spacecraft during both the prospecting and mining phases of our operations. The wide range and diversity of near-Earth asteroids offer a suite of enticing targets.

ACCESSIBILITY
Over 1,500 asteroids are as easy to reach as the Moon. When considering the return trip, that number increases to over 4,000 since an asteroidGÇÖs gravity well is quite weak when compared to that of the Moon. Several dozen asteroids require less energy than is required to put a television satellite into geostationary orbit. Water extracted from asteroids can be used for the rocket fuel needed for the return trip to Earth. This further improves the accessibility of asteroids.

DISTANCE FROM EARTH
While it is likely that some of Planetary ResourcesGÇÖ spacecraft will fly a lengthy trajectory to visit a distant asteroid, in certain cases, especially during our earliest missions, it can be helpful to target asteroids when they travel through the Earth-Moon system. Most asteroids do not travel that close to the Earth, but some do.

Given the rapid rate of discovery of near-Earth asteroids GÇô and the increasing power and capability of asteroid surveys GÇô it is quite likely that many of the best GÇ£neighborhood fly-byGÇ¥ candidates have yet to be discovered. In fact, some of Planetary ResourcesGÇÖ final destinations may only be found after our robotic explorers are already in space, a flexibility allowed by our distributed and responsive strategy for mission design.

SYNERGY WITH NASA HUMAN MISSIONS
NASA is conducting analyses of the best asteroids for a human asteroid mission in 2025. Although NASAGÇÖs requirements for a human missions are different than Planetary ResourcesGÇÖ requirements for a robotic mission, there is synergy between NASA and Planetary Resources in asteroid selection. Asteroids characterized and explored by Planetary Resources during prospecting missions may also help NASA characterize potential human-mission targets.

Can you guess what this thread was about?!