Luke M Coffey Lauren Humphreys Honors Geology 2 April 21, 2016 Alien Planet Kepler-452b Our Milky Way Galaxy is filled with exoplanets—statistically speaking at least one for each of the hundreds of billions of stars in the galaxy. An astonishing finding is that the most common type of planet in our galaxy are those with sizes between those of Earth and Neptune. This has become a new class of planet that is neither terrestrial nor giant and one without an accepted theory for its formation.
Planets on orbits between the hot planets and the cold planets are also known, and of particular interest is the “habitable zone,” or “Goldilocks zone,” the zone around a star where a rocky planet with a thin atmosphere, heated by its star, can have liquid water on its surface. So far, a number of small, presumably rocky, planets in the habitable zone are known, mostly from the Kepler space telescope. This includes Earth-sized planets, one of them being Kepler-452b. In 2015 NASA scientists, using the Kepler telescope, discovered what they believe to be an Earth-like planet located 1,400 light years away (still in our Milky Way galaxy).
Now nicknamed Kepler-452b, or Earth 2. 0, it is 60% larger than Earth, yet still smaller than the larger planets. The exoplanet orbits a star slightly larger and brighter than our sun but falls in its Goldilocks Zone, meaning it is not too hot or close to the sun, but also not too cold or far away from it. This makes it a top candidate for life. The temperature of Kepler-452b would be almost just right for potential life to live on. It is mainly covered in water too, which is the key to life.
The Milky Way has almost 100 billion stars, with potentially more planets and likely alien ife. This raises the questions: “Are we alone in this universe? ” and “Are there other intelligent beings? ” What makes Kepler-452b remarkable is that it orbits its star at about the same distance that Earth orbits the sun. Also, its home star looks to be similar to our sun. This Earth-like world has a ‘substantial opportunity’ to host life, and according to NASA, if plants were transferred there, they would likely survive. However, being 1. 5 billion years older than our planet, the newly discovered cousin provides a glimpse into the future of Earth.
By the time Earth reaches the same age as the distant planet, our sun will trigger a catastrophic greenhouse effect in Earth’s atmosphere – drying up oceans and making the land a desolate desert. If Kepler-452b has a similar geographic composition to our planet, then it is in danger of entering catastrophic phase of its life. The planet is 60% bigger than Earth, and is located about 1,400 light years away in the constellation Cygnus. Its discovery brings the total number of confirmed planets to 1,030. It is the closest twin to Earth, or the Earth 2. that that’s been found yet by scientists. Kepler-452b may be larger than Earth, but its 385day orbit is only 5 per cent longer. The Goldilocks zone that it exists in allows liquid water to pool on the surface of an orbiting planet. Earth 2. 0 is also 5 per cent farther from its parent star Kepler-452 than Earth is from the sun. It receives the same kind of spectrum and intensity of light as we do on Earth, which means plants from our planet could grow there if it were rocky and had an atmosphere. It would even be possible for humans to get a healthy tan here.
However, getting to Kepler-452b might take a while, since it’s 1,400 light years away. While its mass and composition are not yet known, previous research suggests that planets the size of Kepler-452b have a good chance of being rocky. The 6 billion years Kepler-452b has spent in the habitable zone of its star is a substantial amount of time for life to arise, should all the necessary ingredients and conditions for life exist on this planet. Also, Kepler-452b could be experiencing now what the Earth will undergo more than a billion years from now.
If it is indeed a rocky planet, its location could mean that it is just entering a runaway greenhouse phase of its climate history. Its ageing sun might be heating the surface and evaporating any oceans. The water vapor would be lost from the planet forever. Even if the water on Kepler-452b were to one day evaporate forever, the presence of such vast coverings of water could point to the existence of marine life. For instance, modern “alien” cephalopods might currently dwell in its oceans.
A cephalopod is any member of the molluscan class Cephalopoda, and these exclusively marine animals are characterized by their bilateral body symmetry, prominent heads, and a set of arms or tentacles modified from the primitive molluscan foot. Cephalopods are most common in shallow near-shore environments, but they have also been found in deeper waters. They were thought to have arisen from within the tryblidiid monoplacophoran clade. However, genetic studies suggest that they are more basal, forming a sister group to the Scaphopoda but otherwise basal to all other major mollusc classes.
These would give rise to modern Octopuses, squid and cuttlefish. These marine animals have all shown themselves to be adept at escaping through spaces as small as a coin, in case they ever need to survive environmental dangers or predators. They are constrained only by their beaks, the only inflexible part of their bodies. This evolution of the beak may point to a common r, or a future descent in modification in certain animals like birds and other aviating creatures with beaks. If not octopuses, squid, or cuttlefish, a water covered planet like Kepler-452b might be home to “alien” cetaceans.
This includes whales, dolphins, and porpoises. Even though these marine creatures live in water and look like giant fish, they have a very different anatomy. Whales, in particular, can be analyzed for their uniqueness. They have placentas and give live births, feed milk to their young, are warm blooded, and do not have gills but instead have two fully developed lungs. Whales do not have noses like mammals, but have blow holes instead, just like all cetaceans. These animals have different sets of blowholes, but they all have two nasal passages in their skulls inside the head.
Whales even have hair on their heads, just like land mammals. They strangely also have arm, hand, wrist, and finger bones inside their front flippers, just like bats, hippos, and humans have in their front appendages. These modern whales do not have hind legs but do have a small set of bones where the hind legs should be, a sign of this evolution. These bones almost appear to be shrunken hip, thigh, and shin bones, ever and socket joints. The cetacean embryos start with arm and leg buds, but over time the arms grow into fins and the leg buds stop growing.
The embryos also have the two front nostrils, but overtime these move to the top of the head becoming the blowholes. As is evident in the fossil records of Basilosaurid whales, from about 34-40 million years ago, the skull contains nasal openings right in the middle of the head’s snout, not on top like modern whales or at the end of the snout like modern land animals. This points to the evolutionary occurrence of intermediate species. Basilosaurid whales also had small yet fully developed hips, complete with hips, legs, ankle, feet, and toe bones.
These tiny legs would have been much too small for walking on land, but instead may have been useful for mating and scratching away parasites. The maiacetus innuus, from about 47. 5 million years ago, has larger back legs and sturdier hips for walking on land, yet this animal is still considered to be a whale. Where their fossils have been found tell us they lived in the ocean, and their short legs with long, flat fingers and toes suggest they were strong swimmers with webbed hands and feet. Its fossilized skull and jaw teeth and ear bones match it to the modern and ancestral whales.
These fossils, along with many others found and analyzed by scientists, solidify the theory that whales came from land creatures. Lastly, the DNA of whales most closely matches with modern hippos, which most likely means that the two animals stem from a common ancestor, and evolved over time for many reasons, including natural selection, descent with modification, and exaptation. Whales are mostly carnivores while hippos are mostly herbivores, yet similarities still do exist. The ancient whale ankle bone matches the hippo ankle bone. Like whales, hippos give live births and nurse their newborns under water.
They both have multi-chambered stomachs, common for herbivores but very uncommon for carnivorous mammals. Neither animal has fur, but they both have internal testicles, which is rare among all other mammals. Because of all these reasons, it would be easy to declare that even “alien” whales or hippos could evolve from ancient land animals. Due to the evidence of evolution between two very different “alien” animals, it would be clear to say that they are related and evolved from a shared ancestor. Kepler-452b would be the perfect place for these alien aquaticdwellers.