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A |     Washington, Oct 12 (UNI) American space agency NASA says its recent attempt to deflect the path of an asteroid was successful, after its Dart probe struck an asteroid head-on.
Scientists have now confirmed the orbit of a 160m-wide space rock known as Dimorphos was altered when the Dart probe struck it head on last month.
Researchers came to the conclusion after making measurements using a range of space and Earth-based telescopes.
The mission was conceived to test a potential strategy to defend the Earth against threatening objects.
Dart's achievement proves such an idea would work, provided it was initiated early enough and the target wasn't overly massive.
"This mission shows that Nasa is trying to be ready for whatever the Universe throws at us," said agency administrator Bill Nelson.
"I believe that Nasa has proven that we are serious as a defender of the planet," he told reporters.
The space agency released a raft of data on Tuesday to support its assessment, including new pictures from the Hubble Space Telescope and from a small Italian spacecraft that stood off from the impact by about 50km (30 miles).
The Double Asteroid Redirection Test (Dart) took place some 11 million km (7 million miles) from Earth.
It saw the refrigerator-sized Nasa satellite drive straight into Dimorphos at 22,000km/h (14,000mph), destroying itself in the process.
The space rock orbits a much larger (780m wide; 2,550ft) object called Didymos. Before impact, the time taken for Dimorphos to make one circuit of its sibling was 11 hours and 55 minutes.
The telescope evidence now indicates this orbital period has been reduced to 11 hours and 23 minutes - a change of 32 minutes. This corresponds to Dimorphos moving closer into to Didymos by "tens of metres".
Nasa had defined a minimum successful period change of Dimorphos of 73 seconds or more. The results released on Tuesday show Dart surpassed this benchmark by more than 25 times.
"This is a 4 percent change in the orbital period of Dimorphos around Didymos. Dart just gave it a small nudge. But if you wanted to do this in the future, you'd want to do it years in advance," commented Nancy Chabot from the Johns Hopkins University Applied Physics Laboratory, which led the mission for Nasa.
"Warning time is really key here in order to enable this sort of asteroid deflection to be used in the future as part of a much larger planetary defence strategy."
Nasa's Dart programme scientist, Tom Statler, also had a word of caution about drawing too many conclusions from the experiment.
Asteroids came in many different guises, he said. Their compositions and constructions were diverse - something that was being emphasised every time a mission visited a new object.
"We should not be too eager to say one test on one asteroid tells us exactly how every other asteroid would behave in a similar situation," he stressed.
"But what we can do is use this test as an anchor point for our physics calculations in our simulations that tell us how different kinds of impacts in different situations should behave."
Four years from now, the European Space Agency (Esa) will have three spacecraft - collectively known as the Hera mission - at Didymos and Dimorphos to make follow-up studies.
UNI ING。    长城网·冀云客户端记者 乔娅 郑佳洵 白亚军“这是林业局给咱发的碳票，以前想都不敢想，靠着管护山林、净化空气也能挣钱。”承德市围场满族蒙古族自治县哈里哈乡莫里莫村党支部书记何艳丰感叹道。

B | 在省最北部的围场，一片片曾经“沉睡”的山林正在苏醒。作为京津重要生态屏障，围场森林面积达816万亩，其中集体林面积513万亩。然而，长期以来，集体林经营管理面临管理粗放、经营方式单一、林地经济效益低、林农受益程度小等难题。莫里莫村村民李晓东向记者展示林业碳票。长城网·冀云客户端记者 白亚军 摄如何让绿水青山变成真正的金山银山？滦河林场“国有带民营”的改革实践，给出了答案。为破解集体林业发展瓶颈，近两年滦河林场创新构建“国有带民营”集体林权制度改革新机制，以村集体为核心单元，整合村民个人林木资源，集中组建村级集体林场，再通过集体林场与国有滦河林场深度合作、委托经营的模式，盘活全域集体林业资源。目前，全县已成功组建莫里莫村、对亭沟村、台子水村、八十三号村、杜家店村5个村级集体林场，规范化经营林地面积达17.18万亩，规模化、专业化、科学化的林业经营新格局加速形成。何艳丰告诉记者，去年莫里莫村委托滦河林场经营了556亩林地，完成首单林业碳票交易，交易总额6420元。按照收益分配机制，70%碳汇收益归村集体所有，主要用于村里道路维修或者防汛等方面的建设，30%划归国有滦河林场用于森林的管护和保养。滦河林场“国有带民营”委托经营试点。

C | 长城网·冀云客户端记者 白亚军 摄莫里莫村是省“国有带民营”改革的首批试点村落，也是改革成效的生动缩影。目前，该村共委托国有滦河林场经营林地面积2550.4亩，其中2022年12月启动、2023年底全面完工的抚育经营地块面积1151.9亩，林地主要为38年树龄的落叶松。在国有林场专业化管护赋能下，这片曾经无人精细化打理的林地实现质效双升，上千亩抚育林木一年即可实现蓄积增值16.6万元。

D | “以前村里森林覆盖率高达83%，但村民不懂专业管护，树木长势差、卖不上价。

E | ”何艳丰坦言，自从和滦河林场合作后，林地全面落实病虫害防治、科学抚育、规范养护等专业措施，林木长势逐年向好、径级不断增大，2028年还将开展新一轮抚育作业，届时千亩林地预计可增收七八十万元。滦河林场场长王利民介绍，截至目前，该林场累计实施委托经营林木抚育3.37万亩，为乡村增收2630万元；组建凤凰岭林场、百木林场、聚宏林场、秀松湖林场、全峰珍龙林场、承德城御晟林场、承德嘉杉林场等7个家庭林场，经营规模达4万亩。滦河林场场长王利民（右）检查树木生长情况。长城网·冀云客户端记者 白亚军 摄“2026年滦河林场计划将委托经营林木面积突破30万亩，进一步带动集体林经营提质、林农稳步增收；规范有序发展林下特色产业，不断拓宽‘两山’转化路径；积极推广樟子松嫁接红松实用技术，推动林业产业提质增效。”王利民说。从“沉睡山林”到“点绿成金”，滦河林场“国有带民营”的改革实践，不只是一份碳票的兑现、一组数据的跃升，更是发展理念的深刻变革。如今，国有林场改革的种子已在多地生根发芽，生长出绿色希望，让更多村庄因林而兴，让更多百姓因绿而富。

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Published on:07:18:21