When we think of extraterrestrials, we tend to think of little green men in flying saucers. However, no intelligence is needed to travel between planets and solar systems. There is a whole range of organisms that can do this. The intelligent ones are but a small portion of the range of possibilities.

The Tardigrade

The Tardigrade is a microscopic eight-legged creature capable of surviving the vacuum of space. They are found everywhere from mountain tops to the deep sea and mud volcanoes, from tropical rain forests to the Antarctic.

Tardigrade

By Schokraie E, Warnken U, Hotz-Wagenblatt A, Grohme MA, Hengherr S, et al. (2012) – Schokraie E, Warnken U, Hotz-Wagenblatt A, Grohme MA, Hengherr S, et al. (2012) Comparative proteome analysis of Milnesium tardigradum in early embryonic state versus adults in active and anhydrobiotic state. PLoS ONE 7(9): e45682. doi:10.1371/journal.pone.0045682, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=22716809

If Earth were to be hit by a cataclysm in which a part of our crust was thrown out into space, some Tardigrades may find themselves as involuntary astronauts. A small portion of these may later find themselves on a moon of Jupiter or some other place not too hostile to life.

Tardigrades can shut themselves down biologically for decades, or even thousands of years. So, they may find themselves alive and well at their destination where they resume their life functions.

These brave survivors of space travel can then be properly termed extraterrestrials.

Seeding a young planet

A young planet can thus be seeded:

A cataclysm on a distant planet throws up a bunch of dirt and water full of primitive life forms. This muddy mess is sprayed everywhere into space. Some of it directed towards other planets. Frozen solid in the vacuum of space, the organisms carried along for the ride survive for millions of years.

On arrival at a hospitable planet, the ecosystem of microorganisms that was blown into space comes to life once more. Since there’s an abundance of available space for the organisms, we get an explosion of life.

The Cambrian explosion that happened millions of years ago here on Earth may well have happened this way.

Dangerous newcomers

On a later date, when there’s already an abundance of life, a similar arrival of newcomers may cause great trouble. The newcomers may kill off certain species in favor of their own survival. Bacteria and parasites may cause plagues that kill a large number of inhabitants.

However, planets have magnetic shields that prevent external matter from entering their atmospheres. So, there are times when very little dirt gets in, and there are times when more dirt comes in. It all depends on the strength of the magnetic shield.

The magnetic shield is in turn dependent on solar activity. At times of low solar activity, the shield is at the weakest. All sorts of nasty stuff gets through it. This ranges from cosmic radiation that causes earthquakes and bad weather, to dirt and cosmic dust. So, the perfect time for a hostile horde of parasites to enter a planet’s atmosphere is when solar activity is at a minimum.

This is also why severe weather, volcanic eruptions, earth quakes, famines, disease and general misery tend to go hand in hand.

The Black Death

History books are full of stories in which terrible things happen in sequence or all at once.

A prime example of this is the Black Death which killed off 50 to 70% of humankind in the late middle ages.

The chronicles from that time are full of references to obnoxious fumes, asteroids and comets. These things came together, often as a package. One thing followed the other, and they were all associated with death and destruction.

So, the Black Death may well have been a strand of extraterrestrial bacteria for which the human immune system was badly prepared.

It appears then that primitive organisms, from bacteria and parasites to the Tardigrade, permeate the universe. When they rain down on young planets, they kick-start processes necessary for more complex life forms to appear. In established ecosystems, they can wreck havoc, killing off large portions of the population.

Venus

If the planet Venus is a recent newcomer to our solar system, as we suspect, we can expect the seeding process to start shortly, if it hasn’t already started.

This will turn Venus’s thick and hot atmosphere into something less lethal, and it will happen quickly. The time required for Venus to become relatively hospitable may not be millions of years, as conventional theory would have it, but more like thousands of years.

With deliberate seeding from our part, we may even be able to influence the development of Venus in a direction that is particularly welcoming to us. If so, human colonies on Venus may appear in a not too distant future.

The fact that Earth appears to be expanding indicates that it may be getting close to the end of its optimal period. Moving to a new and fresh planet is then the intelligent thing to do. There’s certainly no harm in establishing a colony on Venus should conditions open for this.

Extraterrestrials from Mars

Following this same logic, it’s not unreasonable to think that Mars was once an inhabited planet. If it had a thicker atmosphere, conditions could have been ideal.

If Mars was inhabited by intelligent life, they may once have viewed Earth in much the same way that some of us view Venus today. Earth was their planet B. They seeded it. Made conditions ripe for moving, and left Mars for their new home.

Some time into the future, some other planet may appear. Or a moon of Jupiter turns out to be ideal. A move from Venus to this other place may then make sense.

Intelligent life can in this way be sustained beyond the lifespan of their host planets. Instead of relying on random scatter to move from one planet to another, intelligent beings can seed and move to planets directly.

Interstellar extraterrestrials

However, there might eventually come a time when our region of the Milky Way galaxy becomes inhospitable to life. If matter becomes increasingly heavy and radioactive over time through mass condensation, it will eventually collapse into radiation. If so, humankind will have to move far away in order to avoid the catastrophe.

The intelligent thing to do in an eternal universe, where matter evolves in great cycles, is to be perpetually on the move from less hospitable places to more hospitable places.

We can therefore expect intelligent extraterrestrials to move from time to time. After a certain period on a planet, they move on to other places. They establish planetary colonies, and they branch out in various directions.

Conclusion

This opens for the possibility that intelligent extraterrestrials have in fact been visiting Earth in the past. They may have been here for a while, and then decided to go somewhere else. Chances are that Earth is past its prime when it comes to being hospitable to life. The visitors may have known this and decided to leave for somewhere better.

It’s also possible that we ourselves are the result of such visits. We may even be descendants of extraterrestrials.