| Micele |
4 januari 2019 11:21 |
Zo simpel was het ook weer niet, de Chinezen is het toch maar gelukt.
#NASA was alvast onder de indruk:
De landing werd beschreven als "een indrukwekkende prestatie" door NASA-beheerder Jim Bridenstine.
Citaat:
https://nl.wikipedia.org/wiki/Zuidpool-Aitken-bekken
Het Zuidpool-Aitken-bekken is een inslagkrater op de Maan. De krater is ongeveer 2500 kilometer in diameter, en 13 kilometer diep. Daarmee is het de op een na grootste bekende inslagkrater in het zonnestelsel. De grootste bevindt zich op het noordelijk halfrond van Mars, en is viermaal zo groot.
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Citaat:
https://en.wikipedia.org/wiki/Von_K%...(lunar_crater)
Von Kármán is a lunar impact crater that is located in the southern hemisphere on the far side of the Moon. The crater is about 180 km in diameter and it is located within an even larger impact crater known as the South Pole–Aitken basin of roughly 2,500 km (1,600 mi) in diameter and 13 km (8.1 mi) deep.[1] Von Kármán crater is the site of the first soft-landing on the lunar far side by the Chinese Chang'e 4 spacecraft on 3 January 2019.
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Uitgebreide technische uitleg via:
Citaat:
https://www.theguardian.com/science/...n-basin-crater
Far side of the moon: China's Chang'e 4 probe makes historic touchdown
Lander sends back first close-up shot of previously unexplored side of the moon
(....)
The landing was described as “an impressive accomplishment” by #Nasa administrator Jim Bridenstine :
Citaat:
https://twitter.com/JimBridenstine/s...78873422016513
Jim Bridenstine Geverifieerd account
@JimBridenstine
Congratulations to China’s Chang’e-4 team for what appears to be a successful landing on the far side of the Moon. This is a first for humanity and an impressive accomplishment!
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Martin Wieser, a scientist at the Swedish Institute of Space Physics and principal investigator on one of the instruments onboard Chang’e, said: “We know the far side from orbital images and satellites, but we don’t know it from the surface. It’s uncharted territory and that makes it very exciting.”
A significant challenge faced by the Chinese team was the inability to communicate directly with the spacecraft. Signals to and from the rover are being relayed through a satellite called Queqiao (Magpie Bridge). Queqiao is in a “halo orbit” on the other side of the moon, from where it can communicate with both Chang’e and the Earth.
During the final phases of the approach, however, Chang’e 4 was on its own and could not be operated remotely. Starting from an altitude of 15km, the craft used a rocket booster to decelerate.
At 100 metres above the lunar surface, the probe briefly hovered to identify obstacles and measured the slopes on the surface. Avoiding any boulders or ditches, it selected a relatively flat area and resumed a slow, vertical descent, touching down softly in the Von Karman Crater within the South Pole-Aitken Basin, according to a report by the Xinhua news agency.
During the final phases of the approach, however, Chang’e 4 was on its own and could not be operated remotely. Starting from an altitude of 15km, the craft used a rocket booster to decelerate and a high-tech camera and laser measurements to avoid boulders and ditches.
Chang’e 4 targeted the Von Kármán crater, which was predicted to have a smooth volcanic floor and which sits within the great Aitken basin.
“This is a great technological accomplishment as it was out of sight of Earth, so signals are relayed back by their orbiter, and most of the landing was actually done autonomously in difficult terrain,” said Prof Andrew Coates, a space scientist at UCL’s Mullard Space Science Laboratory. “The landing was almost vertical because of the surrounding hills.”
(....)
The Aitken basin, where Chang’e 4 has landed, is the Moon’s largest and oldest impact crater. Dating when the basin was created could help narrow down the window for a period of heavy bombardment of the moon and inner planets by asteroids left over from the formation of the solar system. Intriguingly, the timing of the heavy bombardment closely coincides with when life appeared on Earth and scientists are trying to work out the exact sequence and whether the bombardment by asteroids might have created the conditions for life.
“Understanding the intensity and timing of the bombardment is important as … that was going on about the same time that life appeared on Earth,” said Ian Crawford, professor of planetary science and astrobiology at Birkbeck University, London. “The Earth has lost its record of that very early time.”
During the coming weeks mission control are expected to spend time testing that the rover is operating as expected, before starting to collect data and beam it back to Earth. Weiser said he expected to get the first batch of data back in mid-February.
In the next phase of China’s lunar programme, the Chang’e 5 and 6 missions will attempt to collect lunar samples and return them to Earth. Chang’e 5 is due to launch in December next year.
• This article was amended on 4 January 2019 to correct the spelling of Nasa administrator Jim Bridenstine, from Brindestine as an earlier version said.
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