Updated: 28/04/2020
Possible Life similarities between Jupiter's moon Europa and depths of the Oceans on Earth
NASA’s next mission back to Jupiter’s moon Europa just took another big step towards reality. The next phase of Europa Clipper has been confirmed, giving the go-ahead for the mission to proceed to final design, construction and testing.
“We are all excited about the decision that moves the Europa Clipper mission one key step closer to unlocking the mysteries of this ocean world,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “We are building upon the scientific insights received from the flagship Galileo and Cassini spacecraft and working to advance our understanding of our cosmic origin, and even life elsewhere.”
Europa Clipper will be the first spacecraft to study Europa up close since Galileo in the early 2000s, and will focus on determining the habitability of the moon’s global subsurface ocean. That ocean is thought to be quite similar to oceans on Earth, although it is completely covered by an outer ice crust. But thanks to previous studies, scientists know that it is salty with a rocky ocean bottom likely rich in chemical nutrients that life could use for food and energy. There may even be hydrothermal activity similar to the vents on the ocean bottoms of Earth. Such hot spots can be an oasis for a wide variety of life forms, even at great depths with no light.
Below Europa’s cold, icy surface lies a deep, salty liquid water ocean which could be home to some form of life. Image Credit: Britney Schmidt/Dead Pixel VFX/Univ. of Texas at Austin
That ocean makes Europa one of the best places in the Solar System to search for evidence of extraterrestrial life, along with Saturn’s moon Enceladus, which although smaller, also has a global subsurface ocean under its icy surface.
Artist’s conception of the Europa lander, which had been considered as part of the Europa Clipper mission, but now will probably be a follow-up mission at a later date. Image Credit: NASA/JPL-Caltech |
Enceladus has huge water vapor plumes that erupt from cracks in the surface near the south pole. The Cassini spacecraft sampled those plumes directly and found they contain water, salts and both simple and complex organic molecules. The plumes originate from the ocean below, so this analysis provides clues as to the conditions in the ocean and how habitable it is. Enceladus’ ocean also appears to be very similar to Earth’s oceans, and there is even more evidence for active hydrothermal vents on the ocean floor.
Europa may also have similar plumes, but they have been more difficult to confirm since they seem to be smaller and more intermittent. New evidence for them from the Hubble Space Telescope was announced last year, however. Americaspace
ALIEN OCEAN NEXT NASA'S MISSION TO EUROPA
SAN FRANCISCO — There's a good chance that NASA's highly anticipated Europa mission will do much more than just fly by the ocean-harboring Jupiter moon.
NASA has already selected the nine primary science instruments for the Europa (moon) spacecraft, whose core mission involves performing dozens of flybys to gauge the Jovian satellite's life-hosting potential. But the probe should be able to accommodate an additional 550 lbs. (250 kilograms) of payload, and NASA would rather not let that "excess" go to waste.
"There's a variety of things that we can do," Jim Green, the head of NASA's Planetary Science division, said here Tuesday (Dec. 15) during a town hall presentation at the annual fall meeting of the American Geophysical Union (AGU). "Perhaps plume probes, perhaps penetrators, or even a small lander." [Europa May Harbor Simple Life-Forms (Video)]
There's no guarantee that any additional instruments or miniprobes will make it onboard the Europa spacecraft. But the smart money may be on one or two ultimately being selected.
"We're pretty hot on doing something," Green told Space.com after his presentation.
The 1,900-mile-wide (3,100 kilometers) Europa is regarded as one of the solar system's best bets to host alien life. Though Europa is covered by an ice shell perhaps 50 miles (80 km) thick, the satellite also harbors a huge subsurface ocean that contains more water than all of Earth's seas combined.
This ocean is in contact with Europa's rocky mantle, making possible a range of interesting and complex chemical reactions, researchers say.
The $2 billion Europa mission, which does not have an official name yet, aims to investigate the habitability of the moon and its ocean.
The spacecraft is scheduled to launch in the early to mid-2020s and reach the Jupiter system 8 years later, if a "standard" rocket such as United Launch Alliance's Atlas V serves as the launch vehicle. (Using NASA's in-development Space Launch System megarocket would slash the travel time to 3 years or so, Green said.)
The probe would then perform 45 flybys of Europa over the next 2.5 years or so, studying the satellite with high-resolution cameras, a heat detector, ice-penetrating radar and other scientific gear.
None of the nine already-announced instruments were designed to hunt for signs of life. But it's possible that a small deployable plume probe — which would fly through putative plumes of water vapor near Europa's south pole, which were detected in December 2012 but have yet to be confirmed by follow-up observations — could carry life-detecting gear. So could a penetrator, which would slam into Europa's ice shell at high speeds, or a lander, which would touch down softly.
We'll all just have to wait and see if NASA will add these challenges to its Europa to-do list.
Notothenioidei is one of 18 + 1 new suborders from the order Perciformes and includes Antarctic icefish and sub-Antarctic fish. Notothenioids are distributed mainly throughout the Southern Ocean around the coasts of New Zealand, South America, and Antarctica
Evolution and geographic distribution
The Southern Ocean has supported fish habitats for 400 million years; however, modern notothenioids likely appeared sometime after the Eocene epoch. This period marked the cooling of the Southern Ocean, resulting in the stable, ice-cold conditions that have persisted to present day, excepting abrupt, rapid warming in the region in recent years. Another key factor in the evolution of notothenioids is the preponderance of the Antarctic Circumpolar Current (ACC), a large, slow-moving current that extends to the seafloor and precludes most migration to and from the Antarctic region
Alien Antarctic Fish pixelx |
These unique environmental conditions in concert with the key evolutionary innovation of Antifreeze glycoprotein promoted widespread radiation within the suborder, leading to the rapid development of new species wikipedia
Amphipod sand hopper
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from 1 to 340 millimetres (0.039 to 13 in) and are mostly detritivores or scavengers.
There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes terrestrial animals and sandhoppers such as Talitrus saltator.
The body of an amphipod is divided into 13 segments, which can be grouped into a head, a thorax and an abdomen. The head is fused to the thorax, and bears two pairs of antennae and one pair of sessile compound eyes. It also carries the mouthparts, but these are mostly concealed.
Diagram of the anatomy of the gammaridean amphipod Leucothoe incisa wikipedia |
The thorax and abdomen are usually quite distinct and bear different kinds of legs; they are typically laterally compressed, and there is no carapace. The thorax bears eight pairs of uniramous appendages, the first of which are used as accessory mouthparts; the next four pairs are directed forwards, and the last three pairs are directed backwards. Gills are present on the thoracic segments, and there is an open circulatory system with a heart, using haemocyanin to carry oxygen in the haemolymph to the tissues. The uptake and excretion of salts is controlled by special glands on the antennae.
The abdomen is divided into two parts: the pleosome which bears swimming legs; and the urosome, which comprises a telson and three pairs of uropods which do not form a tail fan as they do in animals such as true shrimp. wikipedia
Anglerfish
Anglerfishes are fish of the teleost order Lophiiformes.They are bony fish named for their characteristic mode of predation, in which a fleshy growth from the fish's head (the esca or illicium) acts as a lure.
Some anglerfish are notable for extreme sexual dimorphism and sexual symbiosis of the small male with the much larger female, seen in the suborder Ceratioidei. In these species, males may be several orders of magnitude smaller than females.
Anglerfish occur worldwide. Some are pelagic (dwelling away from the sea floor), while others are benthic (dwelling close to the sea floor). Some live in the deep sea (e.g., Ceratiidae), while others on the continental shelf (e.g., the frogfishes Antennariidae and the monkfish/goosefish Lophiidae). Pelagic forms are most laterally compressed, whereas the benthic forms are often extremely dorsoventrally compressed (depressed), often with large upward-pointing mouths. wikipedia
The above post is reprinted from materials provided by Mike Wall. Note: Materials may be edited for content and length.รข
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