New Delhi: Scientists at the University of Toronto have streamlined the search for extraterrestrial life by using a new artificial intelligence algorithm to help send real signals to space without interference. It has helped them identify eight potential alien lifeforms, the scientists claim.
The quest to discover other advanced life in the universe involves locating technologically-generated signals – called technosignatures – because it is assumed that an advanced extraterrestrial civilization would be sophisticated enough to emit these signals.
Since the 1960s, astronomers working on “SETI” (the Search for Extraterrestrial Intelligence) have used powerful radio telescopes to search thousands of stars and hundreds of galaxies for these technosignatures.
However, interference from technology on Earth like cell phones and TV stations, human disturbance still poses major challenges in the search for intelligent life.
By simulating signals of both types, the team has trained their machine-learning tools to differentiate between extraterrestrial-like signals and human-generated interference.
This new algorithm has resulted in the discovery of eight new radio signals that could potentially be transmissions from extraterrestrial intelligence. The eight signals came from five different stars, located 30 to 90 light years away from Earth. These signals were overlooked in a previous analysis of the same data, which did not use machine learning. Read more
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New type of ice discovered
Researchers at University College London and the University of Cambridge have discovered a new type of ice that more closely resembles liquid water than any other known ices. The finding may rewrite our understanding of water and its many anomalies.
The newly discovered ice is amorphous — that is, its molecules are in a disorganised form instead of being neatly ordered as they are in ordinary, crystalline ice.
Amorphous ice, although rare on Earth, is the primary type of ice found in space. That is because, in the colder environment of space, ice does not have enough thermal energy to form crystals.
For the study, the research team used ‘ball milling’, a process that involves vigorously shaking ordinary ice together with steel balls in a jar cooled to minus 200 degrees Centigrade.
They found that, rather than ending up with small bits of ordinary ice, the process yielded a novel amorphous form of ice that, unlike all other known ices, had the same density as liquid water and whose state resembled water in solid form. They named the new ice “medium-density amorphous ice” (MDA).
The team suggested that MDA may exist inside ice moons of the outer solar system, as tidal forces from gas giants such as Jupiter and Saturn may exert similar shear forces on ordinary ice as those created by ball milling. Read more
Saturn’s moon Mimas hosts internal ocean
Scientists at the Southwest Research Institute have found more evidence suggesting that Saturn’s smallest and innermost moon Mimas may host an internal liquid ocean.
Numerical simulations of the moon’s Herschel impact basin — the most striking feature on its heavily cratered surface — determined that the basin’s structure and the lack of tectonics on Mimas are compatible with a thinning ice shell and geologically young ocean.
NASA’s Cassini Mission to Saturn identified a curious oscillation in Mimas’s rotation, which often points to a geologically active body able to support an internal ocean.
Researchers then worked to better understand how a heavily cratered moon like Mimas could possess an internal ocean. They modeled the formation of the Hershel impact basin. The models showed that Mimas’s ice shell had to be at least 55 km thick at the time of the Herschel-forming impact.
In contrast, observations of Mimas and models of its internal heating limit the present-day ice shell thickness to less than 30 km thick, if it currently harbors an ocean.
These results imply that a present-day ocean within Mimas must have been warming and expanding since the basin formed. Read more
319-mn-yr-old fish preserves earliest fossilised brain of backboned animal
Scientists have revealed the oldest example of a well-preserved vertebrate brain from the CT-scanned skull of a 319-million-year-old fossilised fish pulled from a coal mine in England more than a century ago.
The brain and its cranial nerves are roughly an inch long and belong to an extinct bluegill-size fish. The discovery opens a window into the neural anatomy and early evolution of the major group of fishes alive today, the ray-finned fishes
The team led by researchers from the University of Michigan provides insights into the preservation of soft parts in fossils of backboned animals.
Most of the animal fossils in museum collections were formed from hard body parts such as bones, teeth, and shells.
The CT-scanned brain analysed for the new study belongs to Coccocephalus wildi, an early ray-finned fish that swam in an estuary and likely dined on small crustaceans, aquatic insects, and cephalopods, a group that today includes squid, octopuses, and cuttlefish. Ray-finned fishes have backbones and fins supported by bony rods called rays.
When the fish died, the soft tissues of its brain and cranial nerves were replaced during the fossilization process with a dense mineral that preserved, in exquisite detail, their three-dimensional structure. Read more
(Edited by Uttara Ramaswamy)
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