Listen to this article
The first step in opening up a new frontier is to map it. Our priority for developing the frontier of space should be building a comprehensive and dynamic map of the inner solar system. This should include not only planets and moons but also the millions of resource-rich asteroids.
Government agencies and private entities need to work together on this, to spur economic development, to advance our understanding of the origin of our solar system and to protect Earth from asteroid impacts.
Unlike mapping the surfaces of planets, charting the solar system is complicated by the fact that planets and asteroids are moving in three-dimensional orbits around the sun. Plotting a course to visit an object requires that we know not only where it is now but also its precise orbital parameters so that we can calculate where its trajectory will take it.
The cosmic map’s unique component will be the near Earth asteroids, whose orbits bring them close to Earth and make them strategically, scientifically and economically important. Asteroids are remnants of the formation of our solar system. Studying them and their orbital parameters helps us understand the origins and evolution of the solar system. Knowing which asteroids are easily accessible gives us many more targets for exploration.
Asteroids can hit Earth with devastating effect. In 2013, a 17m-wide asteroid exploded near the Russian city of Chelyabinsk, releasing 30 times more energy than the Hiroshima bomb.
In 1908, a 45m-wide asteroid near the Stony Tunguska river in Siberia destroyed an area the size of metropolitan London. The best known impact is the 10km-wide asteroid that 66m years ago hit what is today the Yucatán area of Mexico, killing off the dinosaurs and 70 per cent of species. Having a map of near Earth asteroids and their orbits will allow us to forecast impacts years ahead and to nudge threatening objects safely off course.
Near Earth asteroids are likely to be drivers of economic expansion because they can provide valuable raw materials and water (to make rocket fuel). It makes sense to harvest such materials in space rather than take them from Earth, obviating the need for expensive rockets to escape from our gravity field.
Preliminary commercial activity is under way. Having a map of near Earth asteroids is akin to charting potential resources that could one day serve as the basis of a resource registry and allow private enterprise to protect its investments. But we cannot mine, explore or defend against an asteroid if we do not know where it is.
Astronomers have observed near Earth asteroids for more than 100 years yet only the largest few are in our inventory: 95 per cent of those larger than 1km in diameter are known, whereas the list of smaller but still dangerous rocks (30m-plus) has barely begun.
Data on the composition and size of each asteroid would be useful to scientists, asteroid miners and planetary defenders. Once these measurements are taken, a significant computational effort will be needed to calculate orbits and associated uncertainties. The data will then need to be put into a form that is accessible to all.
Gathering and processing data for the asteroid map is already part of a worldwide effort by astronomers as well as physicists and computer scientists. Funding is primarily from government agencies; several private corporations and non-profits are making investments.
There has been great progress but more investment is needed in technologies and telescopes.
It is time for space agencies, private corporations, academics and non-profits to work together on a co-ordinated asteroid mapping project, with the goal of filling in the still-missing details on the millions of asteroids in our inner solar system.
Danica Remy is president of the US-based B612 Foundation. Ed Lu is executive director of B612’s asteroid institute