Six years ago, scientists discovered that the beating European lander landed in the second position on the comet. This discovery provided considerable insight into the composition of the icy wanderer.
Philae Lander, part of the European Space Agency (ESA) Rosetta missionDeployed from its mothership on November 12, 2014, and made the first soft landing on the surface of a comet 2.5 miles (4 kilometers) wide. Comet 67P / Chulimov-Gerasimenko.
Philae managed to reach this milestone, but the landing did not proceed as planned. The anchor harpoon of the 220 lb (100 kg) lander failed to launch properly, Philae bounced off Comet 67P in 2000 Two different places Two hours after the first contact with the ground, he rested in the dark cave-like structure. (The gravitational force of this comet is 50,000 times weaker than that of the earth, so objects bouncing there tend to stay for a while.)
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Philae could not capture enough sunlight in its final location to charge its secondary battery, so the lander only collected scientific data for a few days.Nevertheless, the various observations of the lander are still Help scientists better understand 67P and comet.
The Rosetta team quickly discovered Philae̵
ESA Laurence O’Rourke, who led the successful hunt for Philae, said in a statement: “Philae has left us with the last mystery to be solved.” “It’s important to find the grounding point, because Philae is on. The sensor indicated that it has dug to the ground and is likely to expose the original ice layer hidden under it, which will allow us to obtain the valuable value of the billion-year-old ice layer.”
“Skull Peak Ridge” touchdown
A new research report says that the mystery has now been solved. After analyzing a large amount of data collected by the Rosetta orbiter and Pheae, especially starting from the reading of the lander magnetometer, which is located at the end of the 19-inch (48 cm) boom and recorded After each impact, the team led by O’Rourke discovered the second touchdown site.
The researchers pointed out in the report that the location is only 100 feet (30 meters) from Philae’s final resting place. New research, Published online today (October 28) in the journal Nature. O’Rourke and his colleagues determined that Philae spent nearly two minutes at the second landing site, hitting at least four different times in the process.
O’Rourke said: “When viewed from above, the shape of the boulder hit by Philae reminded me of a skull, so I decided to call this area the “cranial crest of the skull” and continue to use the subject as other features observed. “The right’eye’ of the’skeleton face’ is formed by the top surface of Philae compressing dust, and the gap between the boulders is the’skeleton roof gap’. Philae passes between them like a windmill.”
These effects unearthed bright substances, which the researchers identified as water ice. The team members said that these freshly unearthed objects looked completely different from the rest of the surface of Comet 67P, which was weathered in the harsh space environment.
One of these impacts dug a 10-inch deep (25 cm) dent into the comet 67P boulder-a scar that betrayed the very soft body. Indeed, the researchers calculated that the interior of 67P’s ice dust was “puffier than the foam on top of a cappuccino, foam bath, or beach wave,” O’Rourke said.
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The research team further calculated that the porosity of the injured boulder was 75%, which means three-quarters of its empty space. This number is consistent with the overall porosity value of Comet 67P, which was determined by the mission team members in a previous study.
Neither the Philae nor Rosetta orbiters are operating.The lander abandoned the ghost very early, and the task force guided its mothership (which was low on fuel) to a soft, controllable position. Crash on the surface of Comet 67P in September 2016. But the new results show that this long-established task began in March 2004 and has continued to make scientific results.
“This is an amazing multi-instrument result. It not only fills the gaps in Philae’s stretch journey story, but it also gives us an understanding of the nature of music. comet“, ESA’s Rosetta project scientist Matt Taylor said in the same statement, referring to this new research.
Taylor added: “In particular, understanding the strength of the comet is crucial for future landing missions.” “The interior of this comet is so fluffy, it is indeed valuable for how to design the landing mechanism and the mechanical processes required to retrieve samples. Information.”
However, planetary scientist Erik Asphaug pointed out in his “News and Views” article about Philae’s research results that designers of comet sampling missions may face real challenges. Published today in the journal Nature.
Asphaug noted that Philae’s planned touchdown site-the location of the first rebound-is flat.Although these areas (theoretically) are easier to land, they are usually covered by a few meters of “lagging” deposits, and the dust particles are too heavy to be carried away by water vapor and other volatile gases that evaporate when the comet passes. sun, Asphaug wrote.
Therefore, the plains are unlikely to contain the easily accessible primitive material left over from the early solar system. On the contrary, Asphaug wrote, the new results “recommend that the best place to sample comets will not be flat plains, but along newly exposed ridges, cliffs, and boulders, which are more difficult to fall on. “
Mike Wall (Mike Wall) is “outside“(Grand Central Press, 2018; Karl Tate illustration), this is a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook .