LINK<\/strong><\/a><\/p>\n\n\n\n“Highlights<\/p>\n\n\n\n
\u2022 The 0.7-\u03bcm absorption maps of Ryugu were generated by the new flat correction.
\u2022 The 0.7-\u03bcm absorption strength at the equator is stronger than the average.
\u2022 It is suggested that the materials at the equator are fresher than the average.
\u2022 The returned samples should contain hydrous minerals with 0.7-\u03bcm absorption.”<\/p>\n\n\n\n
“Global multiband images of the C-type asteroid (162173) Ryugu were obtained by the optical navigation camera telescope (ONC-T) onboard Hayabusa2. The 0.7-\u03bcm absorption depth of the surface reflectance spectrum, which indicates the presence of hydrous minerals, was not clearly seen on Ryugu using flat field correction data obtained in the preflight measurement. The flat field correction data were obtained in the preflight calibration test only at room temperatures (24\u201328\u202f\u00b0C), whereas most observations around Ryugu were performed at a charge-coupled device (CCD) temperature of approximately \u221230\u202f\u00b0C. To obtain higher accuracy measurements, we used a new flat field correction method using the Ryugu surface reflection data. We confirmed that the flat-field patterns are different in high and low temperature conditions. The 0.7-\u03bcm absorption map generated by the new method shows that the 0.7-\u03bcm absorption near the equator (5\u00b0N\u20135\u00b0S) is stronger than that from 30\u00b0N to 30\u00b0S. We found that the excess of the absorption depth at low latitudes was 0.072%, corresponding to 2.7\u03c3. The spectral analysis also shows that the Ryugu surface at low latitudes is bluer than that at high latitudes and bluer materials tend to show stronger 0.7-\u03bcm absorption than redder materials, suggesting that this region has been subjected to less space weathering and less solar heating.”<\/p>\n","protected":false},"excerpt":{"rendered":"
Shingo Kameda, Yasuhiro Yokota, Toru Kouyama, Eri Tatsumi, Marika Ishida, Tomokatsu Morota, Rie Honda, Naoya Sakatani, Manabu Yamada, Moe Matsuoka, Hidehiko Suzuki, Yuichiro Choe, Masahiko Hayakawa, Chikatoshi Honda, Hirotaka Sawada, Kazuo Yoshioka, Kazunori Ogawa, Seiji…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[77,2350,130],"tags":[3872,5828,263,1771,3991,2244,4704,1479,4684,4899],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25867"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=25867"}],"version-history":[{"count":2,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25867\/revisions"}],"predecessor-version":[{"id":25869,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/25867\/revisions\/25869"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=25867"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=25867"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=25867"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}