Europa: Sea Life
A squid-like creature feeds on the bottom of the salty ocean thought to exist below the icy crust of this moon of Jupiter. Europa is the only large body, other than Earth, that may have large volumes of water capable of supporting life. If organisms exist in this perpetually dark sea, they may exhibit characteristics of deep sea creatures in Earth’s oceans, including bioluminescence and a nutrient chain based around hydrothermal vents.
Terrestrial Planet: Herbivore
On an imaginary Earth-like world, alien grazers use enormous vacuum-like trunks to extract food from the rocky surface. Organisms on distant terrestrial planets may well be strange in appearance and behavior, but the biochemical pathways and bodily structures required for life are most likely constant — within a certain range — across the universe. With an atmosphere and gravity similar to our own, these alien animals feed and move much like their living counterparts on Earth.
Terrestrial Planet: Herbivore
The design for this alien herbivore includes eyes placed on the sides of the head, a feature shared by most plant-eating animals on Earth to give them a wider field of view and early warning about predators. Eyes of alien animals would be most sensitive to the peculiar wavelengths created by the unique combination of stellar type and planetary atmosphere.
Terrestrial Planet: Predator
A trio of alien hunters prepares to attack a herd of plant-eaters. Like most carnivores on Earth, these imaginary alien creatures have binocular vision and bodies built for speed and quick reaction. These creatures also have membranes between the fore and hind limbs for gliding and a pair of venom-loaded stingers used to bring down prey.
Terrestrial Planet: Hunting
In this hypothetical hunting scene, alien predators finish off one of the large grazers with repeated poison stinger strikes. The ground surface in this view is actually a vertical cliff face (notice one of the predators falling to its death down to the river valley below). After the kill, the predators will follow the grazer’s falling carcass and feed down on the valley floor.
Ultra Low Temperature Planet
Another planetary extreme where life might be possible are worlds where the average temperatures are down around the levels of liquid nitrogen (colder than minus 300 degrees Fahrenheit). Such extremes would require organic components and physiologies radically different than those found on terrestrial planets largely dependent on liquid water. Theoretically, if energy is available in some form that can sustain biological activity — even at such low temperatures — life may be possible.
Gas Giant: Atmosphere Aliens
With gas giants like Jupiter and Saturn such a common type of planet, many scientists — and fiction writers — have wondered if life could evolve and survive in such dense, violent atmospheres. This imaginary skyscape shows what one of these gas creatures may look like even though a plausible mechanism for the origin of life in such conditions is beyond the scope of current biochemical investigations.
Along with indigenous aliens, the universe probably also has a fair share of life forms that have mastered the challenges of space travel. Here a fleet of “nomadic” aliens enters a wormhole opened with technologies that are beyond human comprehension.