The European Space Agency Will Send Its First Mars Rover to One of These Two Mysterious Sites


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The European Space Agency Will Send Its First Mars Rover to One of These Two Mysterious Sites

Yesterday 3:55pm

Image: ESA/ATG medialab

Mars rovers are great for many reasons, most importantly, because they allow us to live vicariously through a hunk of metal exploring the Red Planet. NASA’s currently working on a yet-to-be-named rover mission slated for 2020, and is in the process of narrowing down a landing location. Similarly, the European Space Agency (ESA) has just announced that it’s debating two locations for its 2020 ExoMars rover, which will search for signs of ancient life.

“While all three sites under discussion [by ESA] would give us excellent opportunities to look for signatures of ancient biomarkers and gain new insights into the planet’s wetter past, we can only carry two sites forward for further detailed analysis,” Jorge Vago, ESA’s ExoMars rover project scientist, said in a press release. “Both candidate sites would explore a period of ancient martian history that hasn’t been studied by previous missions.”

Texture map for Oxia Planum. Image: NASA/JPL-Caltech/Arizona State University; analysis: IRSPS/TAS-I

The two sites in question, Oxia Planum and Mawrth Vallis, lie just north of the equator, and are both feature geologic deposits that are thought to have formed under wet conditions at some point in Mars’ distant past. Besides the fact that places preserving a history of ancient oceans are a solid choice for alien hunting, both locations are relatively low in elevation, which will afford ExoMars enough atmosphere to help it slow down during its parachute descent.

Mawrth Vallis. (Image: ESA/DLR/FU Berlin)

Oxia Planum is thought to have beds of clay-rich minerals, as it’s believed that about 3.9 billion years ago, several streams of water flowed into this region. Just a few hundred kilometers away, Mawrth Vallis exhibits similar clay-rich deposits, according to observations from orbit. The ESA expects to have a finalized decision about the landing site a year before the big launch.

The ExoMars rover is part of a series of Martian missions by the ESA and Russia’s Roscosmos State Corporation. Last year, the ExoMarsTrace Gas Orbiter reached Mars’ atmosphere, which it’ll soon begin to scope out for methane and other atmospheric gases that could reveal some sort of biological activity, past or present. This next installment will get down and dirty on the surface of the Red Planet itself, and beam information back to Earth via the Trace Gas Orbiter. That’s assuming, of course, that the ExoMars 2020 rover landing goes more smoothly than ill-fated Schiaparelli landing attempt this past fall.

With all this impending Mars exploration, someone better find something good on that planet. No pressure, though.

[ESA]

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This Elusive Giant Octopus Snacks on Giant Jellies


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This Elusive Giant Octopus Snacks on Giant Jellies

A female Haliphron holding an egg-yolk jellyfish in her arms. (Image: MBARI)

The giant deep-sea octopus Haliphron is so rare that marine biologists have seen it just three times in 27 years. Using a robotic sub, scientists have finally caught video footage of this animal at mealtime—revealing its distinct preference for gelatinous sea creatures.

A new study published in Scientific Reports is providing the first observational evidence of Haliphron atlanticus, a normally camera-shy giant deep-sea octopus, feasting on gelatinous prey. Previously, scientists had argued that jellies lack nutritional value, but these latest findings are forcing a reevaluation.

Despite its size, very little is known about this deep-sea octopus. It’s rarely seen in the wild, so much of our knowledge has been gleaned from specimens found in fishing nets. Prior to the new study, marine biologists weren’t even sure what it ate.

This animal is sometimes referred to as the “seven-arm octopus” because of the way the male tucks one of its eight arms into a sac underneath its eye. The males are diminutive, just 12 inches (30 cm) long, but the females are giants, measuring 13 feet (4 meters) in length and weighing as much as 165 pounds (75 kg). It’s one of the more extreme cases of sexual dimorphism in a species.

Using a remotely-operated vehicle (ROV), marine biologists Henk-Jan Hoving of GEOMAR Helmholtz Centre for Ocean Research Kiel and Steve Haddock of the Monterey Bay Aquarium Research Institute (MBARI) observed Haliphron in action. On a recent expedition to the Monterey Submarine Canyon off the California coast, their robotic sub spotted the octopus with a large jellyfish cradled in its clutches.

Image: MBARI

Taking advantage of its large size, Haliphron had managed to grasp and hold the entire jelly, estimated to be about 11 inches (30 cm) in width, within its webbed arms. It then used its beak to bite through the “bell” of the jelly, gaining access to the digestive cavity and the food inside, and to reach the more nutritious parts. By this stage of the meal, the jellyfish was dead, but its bell and its outer fringe remained intact. Incredibly, Haliphroncontinued to hold on to these body parts after it had finished its meal. The scientists suspect this was for defensive purposes or to capture more prey; the jellyfish’s stinging tentacles are still active even after it’s dead.

This field observation inspired the researchers to revisit archived footage ofHaliphron. When they did so, they noticed at least one Haliphron specimen holding onto what appeared to be a gelatinous sea creature. To corroborate these observations, the researchers analyzed the stomach contents of five specimens caught in trawling nets. All of the bellies contained traces of gelatinous zooplankton. In addition, three of the five octopuses had stomachs full of jellyfish, one contained a siphonophore (jellyfish-like floaters), and one a salp (a snake-like gelatinous blob).

Haddock and his colleagues believe that gelatinous sea creatures are an unappreciated food source for marine animals—this despite the fact that other animals, such as ocean sunfish, leatherback sea turtles, tuna, and other large fish, also eat jellies. It’s generally thought that these organisms lack nutrients, but given that the animals who feast upon them tend to be large, this idea doesn’t, ahem, hold water. In the new study, the biologists argue that the weight of a jelly translates to significant biomass, and therefore calories.

Haliphron, like so many other creatures in the ocean, follows a very simple, but effective, strategy: move and eat slowly—but grow large.

[Scientific Reports]