近地小行星之起源與演化;Origin and Evolution of Near-Earth Asteroids

NCU Institutional Repository > 理學院 > 天文研究所 > 研究計畫 > Item 987654321/62388

jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/62388

题名:	近地小行星之起源與演化;Origin and Evolution of Near-Earth Asteroids
作者:	阿部新助
贡献者:	國立中央大學天文研究所
关键词:	物理
日期:	2012-12-01
上传时间:	2014-03-17 11:31:40 (UTC+8)
出版者:	行政院國家科學委員會
摘要:	研究期間：10108~10207;Small bodies of the solar system such as asteroids and comets represent both a potentially rich resource for future space exploration and a threat to the very existence of humankind on Earth due to impact risks. Near Earth Objects (NEOs) have the advantage of being much more accessible for scientific research and space missions than small bodies in the outer solar system beyond Jupiter. A study of NEOs will provide crucial evidences to answer the key questions; (a) How are asteroids and meteorites (and meteor showers) related to each other; compositions and their orbital associations? (b) What are the main characteristics of near-Earth asteroids’ population, size, shape, and rotation? The Panoramic Survey Telescope And Rapid Response System “Pan-STARRS” is a project, initiated by the Institute for Astronomy, University of Hawaii, to repeatedly survey covering three quarters of the entire sky. Since May 2010 the prototype single-mirror telescope “Pan-STARRS-1 (PS1)” has been operating on Mt. Haleakala in Hawaii. The PS1 Science Consortium in 4 countries including National Central University Taiwan is undertaking its 3.5-years scientific research program until Oct 2013. Solar System moving objects such as asteroids and comets are crucial targets for the PS1 project. As of April 2011, about 340 NEOs have been detected and 68 of them were newly discovered asteroids. National Central University (NCU) team has established our own follow-up procedure using TenagraII 32”(~81cm) remote telescope in Arizona, USA. My (Taiwanese) regular contribution to the discovery of PS1 NEOs will surely increase until Oct 2013, the end of PS1 operation. The expected discovery rate of new NEO is about 10-30 per month by PS1 telescope. In order to keep our contribution (follow-up observations of ~50% of PS1 NEOs), I plan to use TenagraII remote telescope about 1 hour every 3 night throughout a year. About 550,000 asteroids were discovered to date and ~7200 of them are NEOs and ~ 1,100 are PHOs (Potentially Hazardous Objects), a subset of NEOs closely approach Earth’s orbit. However, connection between NEOs/PHAs and Earth impactors such as meteorites or meteors are still under debate due to observational biases, large uncertainties of orbital elements and chaotic orbital evolutions due to perturbations by planet gravity and thermal effect called Yarkovsky effect. PS1 NEOs provide more opportunities to investigate the NEO family (which shares nearly identical orbit) and its connection to meteorites. The PS1 provides not only ‘discovered NEOs’ but also ‘known NEOs’ that have observed before. Thus, the orbit of re-observed known NEO by PS1 enables to carry out the minor thermal force “Yarkovsky effect”; absorbed thermal energy during the day is radiated away when the heated surface rotates to afternoon side. This unbalanced thermal radiation produces a tiny acceleration that gradually changes the asteroid’s orbit. In order to understand chaotic orbital evolution, mathematical integrations of orbital elements of NEOs considering the Yarkovsky effect are carried out using the computational cluster.
關聯:	財團法人國家實驗研究院科技政策研究與資訊中心
显示于类别:	[天文研究所] 研究計畫

文件中的档案:

档案	描述	大小	格式	浏览次数
index.html		0Kb	HTML	312	检视/开启

在NCUIR中所有的数据项都受到原著作权保护.

社群 sharing

数据加载中.....