Beyond the Moon and Mars: Marcal Sanmarti discusses the scramble for the inner solar system.

• Author: Sanmarti, Marcal

The inner solar system is the space region that goes between our star, the Sun, and the first asteroid belt in the solar system. Distances in our solar system usually are measured in astronomical units (AU), which is the distance between Earth and the Sun--approximately 150 million kilometres. The distance between the Sun and this asteroid belt is around 3.2 AU. With our current technology, it would take around eighteen months for a crewed mission to arrive there from Earth. It is far away but pursuable. The second asteroid belt at the end of the outer solar system is at a distance of around 30 AU.

Jupiter's four main satellites have also engaged the attention of powers like the United States, the European Union and particularly Russia, but the huge distance separating Earth from Jupiter ensures that the politics of its exploration are mostly about achieving a science first, rather than establishing an outpost. The fact that the planets in the outer solar system are made of gas (according to current science) makes landings impossible. We are going to limit, then, the astropolitical analysis to the inner solar system.

What we find in our immediate solar neighbourhood in space is the Sun and then in order Mercury, Venus, Earth (and its satellite the Moon), Mars (and its satellites Fobos and Deimos) and then a series of asteroids that, even though we call them a belt, are quite far apart from each other. Let us have a look at what this inner solar system, beyond the Moon and Mars, has to offer to international politics.

Obvious value

The value of the star that gives name to our system might seem quite obvious. No Sun, no nothing. It might seem especially relevant during these times of climate change but also energy supply difficulty. Solar panels keep expanding here on planet Earth. Sunlight provides energy for our homes, devices or crops. Sunlight is the main or even only power source not just for human-made satellites and space stations orbiting Earth but also for the probes and rovers exploring the Moon, Mars and other bodies of our solar system.

A proper understanding of how sunlight or even the sun itself works is not just vital to power our devices; as we become more reliant on technology like cell phones, geolocation networks, other satellite services and electrical devices, we find we are more susceptible to the effects of space weather. A branch of the physics of the Sun or helio-physics, space weather is mostly concerned with the effect that the physics of the Sun have on Earth and its surroundings. Solar wind--a stream of charged particles released from the upper atmosphere of the Sun--is an example. It can affect not just Earth's magnetic field and atmosphere but also the amount of radiation we receive from the Sun. The effects of space weather reach spacecraft electronics, spacecraft orbital changes, spacecraft signals, long-range radio signals, humans in space, humans on commercial aviation and many other things related to our modern daily lives.

Just like the terrestrial weather, space weather can be as gentle as a rain shower or as wild as a hurricane. In 1859 a giant geo-magnetic storm coming from the Sun, called the Carrington Event, caused the telegraph systems of Europe and North America to fail. Should a solar storm of this magnitude occur today it will cause widespread electrical disruptions, blackouts and damage due to extended outages of the electrical grid. Repairs would take several months. The effect on the balance of power here on Earth would be immense. It is a serious international concern, and in New Zealand. Local astrophysicists together with Transpower New Zealand are already working on mitigation plans in case solar tsunamis (massive solar shock waves) reach the southern hemisphere, affecting this country's critical infrastructure. (1)

Solar sailing

But scientists and space agencies are also exploring whether this space weather...