We Will Destroy Your Planet (6 page)

Starship crews, however, have the best possible view. Literally. The Earth can be sampled in total from orbit, by all possible kinds of scanners and cameras and sensors. It is a simple matter to map the entire surface, both in the visual spectrum of light for your species, and internally by mass spectrometry, radar, gravitometry, and so on. Using the appropriate sensors from orbit will give you a total picture of the Earth from core to outer atmosphere, as well as showing you where humanity has its military strongpoints, where resource deposits are, and the distribution of life forms. You will also be able to track vehicle movement, and eavesdrop on all electronic communications and broadcasts. Be aware, though, that the Earth has hundreds of languages, and you will need to be able to decode them. (Despite this, you will find from the broadcasts that humans seem to think that all other planets share one single language.)

A warning:
Do
do your research, but be aware of the limitations of your information. Military secrets, generally, are considered to be the shortest-lived as well as the most valuable, but it's less often recognized that simple information is also extremely short-lived in a military context.

As with any commander, you must make sure that your information is as precise and up to date as possible. It must be accurate, and it must be correct for the time of your attack. This brings a bit of a paradox, because, on the one hand you will want to be prepared well in advance with all of the information you need, but that information must also be current at the latest possible moment before conquest. There's no point in knowing where all the defences are before you take off, if they've moved by the time you arrive.

As you can imagine, this is especially problematic for those of you crossing the void in normal space, or even at relativistic speed. If it takes you years to reach the Earth, then the information you have gathered absolutely will be out of date by the time you arrive, unless you have some kind of time travel capability that allows you to move back through time as you cross space, in order to arrive at a point at which your information is current and correct.

It would make more sense, therefore, to conduct your reconnaissance and intelligence-gathering from a forward base – perhaps on the Moon or Mars, or at one of the LaGrange points in the Earth-Sun or Earth-Moon system – so that you can prepare to launch your attack from there.

There are several stages to an invasion of a territory, regardless of the scale or purpose of the conflict. Broadly speaking, defences and warning systems must be rendered ineffective – or at least disrupted – before the following sequence can occur: entering the target territory, establishing secure beachheads which can be linked together to form a stable controlled area for the later reception of reinforcements and supplies, eliminating military resistance in surrounding territory, and consolidating control of suppressed territory.

In Earth's history, invasions have been conducted both by crossing land borders, by landing troops at the coast from maritime ships, and by airborne transport of parachute troops. The most effective landing method for you will depend on your means of transport, and how you arrive at Earth. There is no defensive shielding, so, in order of importance, you will need to deal with the following layers of national defences across most of the planet:

First off, you will need to be sure to neutralize defensive forces on the ground, and eliminate air defences that may intercept your re-entry vehicles. Depending upon how much of the planetary society you want to preserve for whatever reason, your means of dealing with native forces will differ.

If your intent is to preserve and exploit humanity (as slaves, food, or whatever), you will need to be precise in your opening bombardment. Laser strikes from orbit, precision-guided missiles with conventional or antimatter warheads, or low-yield tactical nuclear weapons are all viable options for taking out military bases, command and control centres, and so on.

If you have no interest in preserving the native population, and simply want the planet for its mineral resources or as a strategic garrison, then 20 or so mile-wide asteroids directed to impact on low-lying plains and population centres will eliminate all practical resistance in advance, and save you a lot of time, effort, and logistics in holding the planet later.

It will greatly reduce local forces' ability to organize and coordinate their resistance if you can shut down as close to all terrestrial communications as possible. Doing so will prevent commanders from issuing orders, field units from making situation reports, governments from executing policy, military units from being directed to where your forces are, and so much more besides.

The silence between the authorities and their populations will also have the effect of leaving the populations confused and frightened. They will therefore be more concerned with panicking over their lack of knowledge than resisting your invasion. Similarly, the authorities, especially in urban areas and near political control centres, will have to divert manpower to police their own populations, thus reducing their numbers available to be deployed to the front lines and bridgehead areas where you will be landing.

Fortunately, advances in technology on Earth have actually made this task simpler, rather than more difficult. A couple of decades ago, bringing down the human communications networks would require eliminating exchange buildings filled with electromechanical technology across the globe. Every country and alliance would have to be targeted separately, as they all have separate technical setups and political systems, as well as different chains of command.

Currently, however, Earth has digital communications enabled by microwave transmissions, along with wireless frequencies, and almost all communications devices use microelectronic technology. All of which is vulnerable to the whims of electromagnetism. A strong enough electromagnetic pulse in or near the Earth's atmosphere will render all such devices over a wide area completely useless, preventing any signal transmission. In the local parlance, the technology would be ‘bricked' – in other words as electronically active as a baked lump of clay.

A sufficiently strong EMP might well be able to completely inhibit all such devices across the planet, rendering it radio-dark, and thus preventing any signal communication before your landings. The means to produce such a large EMP are varied, both in natural and artificial means.

The largest and most devastating form of EMP would be a naturally generated gamma-ray burst, either from a stellar event such as a supernova, or from a suitable large solar flare event. Solar weather would have the best chance of blanketing the entire planet with charged protons and electrons capable of taking out vital transformers, satellites, and so on. The US and UK governments, two nations which you will certainly come into contact and conflict with, have both recently produced reports acknowledging that a serious Solar energy event could knock out much of the planet's power and communications systems for weeks, and possibly up to a year.

The best way to engineer a solar coronal mass ejection, which would send a storm of particles out towards the Earth, would be to generate two massive electromagnetic fields over a sunspot – a darker area in the Sun's upper atmosphere – and let the protons and electrons build up into a loop of plasma between the fields, which would then rise in temperature well beyond the Sun's coronal temperature. When the protons and electrons in this plasma reach a terminal velocity of 900,000 mph they join the solar wind. If the particles in the plasma reach the Sun's escape velocity of 1,390,500 mph or above, they can burst into a solar flare or even a full coronal mass ejection – a blast of plasma shot into space like some kind of weapon.

When this plasma hits the Earth's magnetosphere, it actually deforms the Earth's magnetic field, even changing the reactions of compass needles. It also can induce large electrical ground currents in the conductive iron of the Earth itself. This sort of magnetic storm causes aurorae in the atmosphere, damages satellites – or, indeed, visiting and unshielded starships, so be careful about trying this – in orbit, and, if strong enough, will disrupt global communications and wreck electrical and electronic equipment on the surface or in the atmosphere.

However, if your ship is capable of travelling across interstellar distances, and/or travelling faster than light or through hyperspace, it should be capable of generating a suitable orbital EMP pulse. After all, even humanity can do that, which is handy if you're arriving by wormhole, time travel or dimensional rift, and want to use an EMP to knock out planetary communications. All you will need are some nuclear weapons.

It is well known on Earth that nuclear weapons cause an electromagnetic pulse as a first side effect of the detonation of a fission device. For the widest of coverage of the EMP effect, a detonation at an altitude of 250 miles above sea level is recommended. The area affected by the EMP effect will be a roughly U-shaped area, with 60–70% of the effect being on the equatorial side of the detonation. (That is to say, EMPs triggered in the northern hemisphere will mostly affect areas southward of the detonation area, and those triggered in the southern hemisphere will more affect areas northward of the detonation point.)

The amount of energy radiated will vary according to both the altitude of the detonation and the geographical location. The Earth's magnetic field is stronger over land masses and closer to the poles. If identical EMP devices were detonated over both the equatorial Pacific Ocean and the cities of the Eastern Seaboard of the United States, the EMP over those American cities would be at least five times stronger.

Use of nuclear warheads to knock out communications over large areas of land is, therefore, not an impractical solution to the planetary communications network. That said, if you're going to use nuclear warheads you may as well use them strategically to destroy military centres, population centres, and so on while you're at it, and leave the EMP effect just as a side effect.

Humanity has known about the dangers and effects of EMP for decades, however, and some military infrastructures have their electrical and electronic devices shielded against the effect. Interestingly, as the local geopolitical situation on Earth has drifted away from the threat of an exchange of nuclear warheads, and towards lower-key guerrilla actions, the habit of shielding new equipment against EMP has slipped in many of Earth's militaries. Not only that, but more modern technology is more fragile, and microcircuits are less robust than the thick copper wiring and cables of the past, so, with these two changes in circumstance combined, much of the Earth's technology today is actually more vulnerable to EMP than it was at earlier stages of development.

This, of course, is entirely to your advantage.

As the Earth is still not yet a unified society, each of its nation-states has its own militaries with their own command and control centres. These centres are, however, devoted to running operations concerned with other terrestrial nation-states, rather than with planetary defence.

Nevertheless, they will be used to co-ordinate any defence against an assault on the planet as a whole, though it is unlikely that – at least in the early stages of such a campaign – the militaries of rival nations would share their command structures against the common foe.

Many of the main command and control centres belonging to the major military powers are well sheltered, safely ensconced in environs – natural or artificial – proofed against nuclear warheads. In some cases these are specially designed and constructed to be proofed against nuclear strikes, while others are built under natural defences such as mountains, which were already strong enough to withstand such attacks.

Most notably, NORAD and the US Air Force's Space Command (the clue as to why this base is important is in the latter's name) are settled beneath Cheyenne Mountain in Colorado. This is where, in the
Stargate
series of media, the Stargate itself is housed, and the location from which units of Earth soldiers make their forays to other planets. As far as is known, this is still fiction, but you will probably have detected the transmissions on the way to Earth and so be wary of this facility.

Meteor bombardment is, again, going to be the best way to deal with such fortified control centres. Anything over a hundred yards or so across should deal with any underground facility, mountains above them notwithstanding.

Attacks not from space will have to use other means, and this will be tricky for those time travellers and dimension-jumpers relying on the Earth's own weapons to do the job, since, as stated, these facilities tend to be hardened against nuclear blasts. Infiltration and sabotage will be the best options for such invaders.

Those of you with the use of wormholes or teleportation, on the other hand, can have fun with materializing tactical nuclear warheads
inside
the nuke-proof fortifications and the inevitable devastating results.