NASA’s Curiosity Rover May Have Found Fossils on Mars
For years, theorists have suggested that Mars once contained the necessary requirements to support life. Now, NASA’s Curiosity rover may have finally found indication of this from images showing what appear to be fossilized microbial structures.
Over the past five and a half years, NASA’s Curiosity rover has been mapping and imaging the Martian surface to gain more insight on the dusty planet. In addition to snapping pictures, the nomadic vehicle has been searching for signs of water, while also determining the viability for human colonization.
Scientists know that water once flowed on Mars and have been on a quest to discover whether it still does to this day. Aside from ice caps on the Martian poles, evidence of water in Mars’ past can be seen in dried lake beds, gullies, and what was once a large ocean in the planet’s topography.
In recent images of the Gillespie Lake outcrop, in the Yellowknife Bay area, Curiosity sent back pictures of small stick-like formations in a segment of sedimentary rock. To the untrained eye these formations might not appear to be much, but to a microbiologist who has studied microbially induced sedimentary structures (MISS), the pictures seem to have some profound implications.
Nora Noffke of Old Dominion University in Virgina meticulously compared the photo to instances of MISS on Earth and published a paper that has intrigued scientists at NASA. Though she’s hesitant to make any definitive claims, her paper provides some of the best evidence to date for indications of past lifeforms.
The stick-shaped markings aren’t actually considered to be fossils of microorganisms themselves, but rather fossils of their imprints.
Some have contested that these tubular markings are more likely crystals, rather than the footprint of microorganisms. In either case, the finding shows that the area once consisted of a body of water that had the elements needed to support life.
NASA is planning on sending another rover to Mars in 2020 that is nearly identical to Curiosity, with the goal of strictly searching for signs of previous life. Once collected, samples will be sent back to Earth from a small rocket deployed from the rover.
Scientists have recently found other signs of life on the red planet, including fluctuating levels of methane in the atmosphere. Some have proposed the idea that this gas may be coming from life below the surface.
On Earth, methane is produced from bacteria, primarily in the stomachs of animals and humans. Could there be bacteria, or life containing bacteria, producing that methane below the Martian surface?
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Nemesis Star Theory; Does the Sun Have an Evil Twin?
Many people remain anxious about the threat posed from a hidden nemesis planet, known as Nibiru, that has been prophesied to collide with Earth. Though many of the proposed dates for this collision have come and gone, there is another celestial body that may be more likely to lead to an apocalyptic event: The Nemesis Star.
The Nemesis Star Theory
Binary star systems occur frequently and are actually more common than single stars. At least that’s what we thought, until a recent hypothesis proposed the possibility that every star starts out as a binary pair or multi-pair system. While the theory hasn’t been confirmed, there is significant evidence that our Sun likely has a twin, an evil twin.
The majority of stars in the galaxy are red dwarfs, which are a fifth of the size of the sun and up to 50 times fainter. These types of stars are pretty commonly paired with another star in a binary system, leading astronomers to believe that Nemesis would be the Sun’s red dwarf star companion. But due to the small size and faintness of these stars, they can be hard to find, making Nemesis all the more elusive.
binary stars courtesy wired.com
This star is thought to be responsible for 12 cyclical extinction events on Earth, including the one that killed the dinosaurs. The Nemesis Star Theory’s roots can be traced to two paleontologists, David Raup and Jack Sepkoski, who noticed that there was a periodicity to major die-outs throughout Earth’s history, occurring in 26 million year intervals. This led to a number of astrophysicists and astronomers, postulating their own Nemesis Star hypotheses.
So how would the sun’s twin be responsible for mass extinctions? The Nemesis Star Theory proposed the idea that the Earth’s binary twin must be in a large 1.5 light-year orbit, retaining just enough gravitational pull between it and the Sun so as not to drift off. But the issue with the orbit of Nemesis is the possibility that it occasionally passes through a cloud of icy debris on the fringe of our solar system, known as the Oort Cloud.
Don’t Perturb the Oort
The Oort Cloud is a theoretical sphere that is believed to orbit our solar system, consisting of planetesimals, the small icy building blocks of planets, comets, and asteroids. These planetesimals are sticky and collide with each other until they become large enough to have a significant gravitational pull, eventually becoming as large as a moon or a planet. They also create asteroids and comets which can be knocked out of orbit and sent hurtling toward the center of the solar system, crashing into planets.
There is a binary star system that once passed close enough to nearly perturb the Oort, and it was likely visible from Earth. Scholz’s Star made a flyby some 70,000 years ago, at a distance of 50,000 astronomical units (AU), with one AU being the distance from Earth to the Sun. The Oort is thought to extend from anywhere between 5,000 and 100,000 AUs and is believed to contain up to two trillion celestial objects. Astronomers are 95% certain that Shulz’s star passed within half of a light-year of us, possibly perturbing the Oort, though apparently not enough to cause a mass extinction event.
Comets are believed to exist within the Oort and are the product of a thief model, a give-and-take of celestial bodies between stars when they’re formed. In this process, comets get pulled back and forth between the gravitational field of stars. It was for this reason that the Oort was theorized, due to the number of comets coming from it, there had to have been a sibling star that pulled them out to the Oort.
The Oort courtesy of space-facts.com
Astronomers also found a dwarf planet in the Kuiper Belt, a region just before the Oort that also contains icy, celestial bodies. This planet, named Sedna, orbits the Sun in a long, drawn-out elliptical path and is one of potentially hundreds. Sedna may help to explain the Nemesis star theory, in that its far-flung orbit was likely caused by our Sun’s twin, pulling it out as it drifted off into the depths of space. Imagine if instead of 9 planets in our solar system, there were a few hundred?
So where is this Nemesis star? Several years ago, the E.U. launched the wonderfully named, Gaia satellite, to map out the stars in the Milky Way and look specifically at stars that have had a close encounter with our solar system or that might come close in the future. But whether or not Nemesis will be found is unknown; it’s possible that it could make a return for the next mass extinction, or it is possible that it drifted off, perturbing the Oort of another star.
