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"Dawn" exhausted fuel detector NASA will send "successors" – Science Exploration – cnBeta.COM

The National Aeronautics and Space Administration (NASA) recently announced that the "Dawn" detector controls the feared fuel, cannot manipulate its main antenna towards the Earth or direct solar panels towards the sun. Due to lack of mobility, the "Fajar" mission officially ended. The "Dawn" is still in the orbit of Ceres and will remain for decades.

So, should the Earth send a new envoy to Ceres? What is the main mission of the new messenger? The US space network is paying attention to the report on November 6.

Need to enter the surface of Ceres

"Dawn" has found that the surface of Ceres is filled with hundreds of strange highlights, lots of ice water, and organic molecules (basic components of life). But at the end of the "Dawn" mission, scientists still have many big doubts that have not been clarified. Paul Schenk, a scientist who participated in the Ceres mission, and a member of the University's Space Research Association under the Moon and Planetary Institute, said: "To solve this problem, it might be necessary to enter the Ceres surface because information obtained from orbit is still limited. "

Must focus on the Okato crater

Schenk said he hoped to have a detector sent to explore the Occator Crater. An image taken in October 2016 by Dawn shows a bright area in Ceres, right in the crater. This crater is 92 kilometers wide and contains the largest bright spot and light in Ceres, and contains salt deposits – deposits left by salt water which freezes from the ground and freezes on the surface. This discovery revealed that Ceres's interior was warmer than scientists had expected.

In addition, the most common mineral in the Okato crater is sodium carbonate, which is also found in places with hydrothermal activity on Earth (including Yellowstone National Park, etc.). Schenk said: "It is well known that certain bacteria can survive in these places."

But he also said that the survival of microbes in Ceres was "very unlikely" because the heat produced by the impact lasted for a lifetime. It is important to know that the earliest forms of life emerged 700 million years after the formation of the Earth. "This kind of impact produces enough ice to melt sufficiently and produce ground water, which then circulates in the center. But for tens of thousands to millions of years, the heat zone shrinks and the water continues to freeze."

Schenk said that whether Ceres could be a habitat for life, the hydrothermal process seen above could help scientists understand a similar process in other celestial bodies in the solar system, such as wood which is thought to be most likely in space in the solar system. Wei Er, Titan. Like bacteria that live in deep-sea hydrothermal pits on Earth, organisms with similar features in other celestial bodies may not need sunlight, on the contrary, they may depend on geothermal energy to survive.

As far as Ceres is concerned, being exposed to other large space rocks seems to be a source of geothermal energy. Schenck said: "Hydrothermal reactions between impactors and water will clearly form minerals on the surface of Ceres, understanding how this process works on other planets including Mars, and how these materials reach the surface, etc., to understand the entire solar system. Even though we have a lot of information on this planet, the chemical properties of the Earth's crust are very different from those of Ceres. "

Landing and roaming in Ceres

Schenk said that because the Okato crater has several conditions needed for life to appear in other celestial bodies, many scientists hope to send landers to Ceres for further exploration. Ideally, any future mission will include small plows.

"Dawn" can only learn Ceres from orbit, and the closest orbital height to Ceres is 35 kilometers, but the detector that landed on the surface of Ceres can be obtained by extracting samples and analyzing them on the spacecraft to get more about Ceres composition. Information.

Schenck said that the "dawn" detector uses a spectrometer to determine the elemental composition on the surface of a dwarf planet, but the measurement results "are mainly dominated by materials that are spectrally active and can reveal absorption bands of certain wavelengths", while carbon materials good, and is likely to become "net fish." "So we might have to land on the surface to find it."

In fact, in early 2008, scientists have begun working on the initial plan for the next exploration mission from Ceres. The proposed mission, called Ceres Polar Lander, plans to send a combination of orbiters to Ceres, placing landers in the Arctic Arctic for life guidance. The mission plans to use NASA's soft landing technology to prepare for landing on Mars. Theresa Europe Alenia Aerospace and a research team at Nantes University in France presented the concept of the mission at the European Planet Science Conference.

At present there is no space agency planning to send a new mission to Ceres, but because "Fajar" has retired, this situation can change. However, Schenck said that each Ceres exploration mission proposed by NASA must be reviewed after a lengthy review. At the same time, scientists have a large amount of data from "Dawn" to filter. "We just began to understand Ceres, it took a while. To find out what we saw."

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