A | While scientists and science fiction authors alike have long dreamed of sending crewed missions to Mars, a new study suggests these plans may hit a snag – a big one.,The authors of a yet to be peer-reviewed study argue that the participants of such a mission to Mars would end up being exposed to radiation – namely, to “energetic charged particles from Galactic and Solar origin” – both while in transit and while on the planet itself, with the “thin spacecraft shield” and “rarefied Martian atmosphere” offering little in the way of protection.,The research team attempted to gauge the impact of a simulated 1,000-day mission to Mars on various organs of the human body, and concluded that astronauts may be exposed to radiation doses above one Sievert, which is over the safe limit set by most space agencies, New Scientist points out.,“We suggest mitigation strategies such as improved ways of shielding and dietary supplements, and make recommendations for the safety of astronauts in future crewed missions to Mars,” the team wrote in the abstract of their work available on the arXiv preprint server.,Ideas about how astronauts may be protected from radiation during a mission to Mars have already been proposed, such as the concept of a radiation shield comprised of a fungus found growing at the Chernobyl Nuclear Power Plant.,Last year, one architecture studio even unveiled a project for a self-sufficient and sustainable city that would be built on the red planet itself.。
原标题：手机收到7.7级地震预警 官方致歉是偏差大了 韩乔生：不知道大家有没有被吓出冷汗快科技8月24日消息，
今天上午，# 长宁地震误报 #登上热搜，不少网友在社交平台晒出截图，称手机收到了7.7级地震预警弹窗。
据了解，今日8时26分，四川宜宾市长宁县发生4.7级地震。
B | 针对大量用户收到7.7 级预警信息一事，成都高新减灾研究所发布情况说明。通报显示：8月24日8:26四川宜宾长宁发生4.7级地震，成都高新减灾研究所的大陆地震预警网对该地震的预警震级序列依次为7.7级（震后第5秒）、6.4级（震后第6秒）、3.7级（震后第7秒）、4.1级（震后第8秒）、3.9级（震后第16秒）。震级在地震发生的第17秒自动收敛到3.9级。对此次较大的偏差，成都高新减灾研究所表示致歉，并将尽快查明原因，改进技术、改进服务。
知名主持人韩乔生也就此事发文感慨：不知道大家有没有被今早手机弹出的7.7预警吓出一身冷汗？我自己看到弹窗那一刻，也着实心里一紧。事后中国地震台网正式测定，本次地震为4.7级，震源很浅，周边多地震感明显。他指出，出现7.7级这个数字，是地震预警系统在地震发生后短短数秒内，依靠有限监测数据快速测算产生的巨大偏差，后续数值会持续迭代修正。成都高新减灾研究所也针对本次较大偏差发布情况说明并且公开致歉。
C | 韩乔生表示：亲身经历就能体会，弹窗跳出来的那一刻很容易心生恐慌。
D | 预警的初衷是为大众争取避险窗口，但初估数据客观上会存在误差。面对地震相关消息，一切还是要以中国地震台网的正式通报为准。
