[:ja]NASAの小惑星探査機OSIRIX-RExが地球から512万kmの距離から撮影した地球と月です。地球と月の距離は約38万kmですが、画像中の地球ー月間の距離が38万kmを表すでしょうか？
答えはNoです。以下の地球、月、OSIRIX-RExの間の位置関係を見ると、地球ー月間の直線に対して探査機の位置が正対しておらず、142度の角度からの撮影なので、正対すると、地球と月はもっと離れるのです。
ちなみにOSIRIX-RExはOrigins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer の略で、NASAゴダード宇宙飛行センターがアリゾナ大学月惑星研究所などと共同開発している、小惑星ベンヌからのサンプルリターンを目的とした宇宙探査機です。2016年9月に打ち上げ、ベンヌ到達は2018年、地球への帰還は2023年の予定です。
参考文献：
ウェブ地球儀で地球俯瞰画像を見る： LiVEARTH
[Earthview Wonders] No.425: Earth and Moon
NASA’s OSIRIS-REx captured the Earth-Moon system from the point 5,120,000km away from the Earth. Earth-Moon distance is 380,000km but does this distance between 2 planets express the distance?
The answer is no. OSIRIS-REx is at the point where it creates obtuse angle of 142 degrees in the triangle as follows so the distance in the image is shorter than 380,000km.
The purpose of NASA’s OSIRIS-REx spacecraft (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) is to map and return samples from asteroid Bennu, a carbon-rich hunk of rock that might contain organic materials or molecular precursors to life. In other words the mission to figure out where we came from, as asteroids are remnants from the formation of our solar system. The spacecraft is expected to reach its asteroid destination, Bennu, in December 2018, with approach operations starting in August.
Reference:
See earthview photo gallery with web-globe: LiVEARTH[:en][Earthview Wonders] No.425: Earth and Moon
NASA’s OSIRIS-REx captured the Earth-Moon system from the point 5,120,000km away from the Earth. Earth-Moon distance is 380,000km but does this distance between 2 planets express the distance?
The answer is no. OSIRIS-REx is at the point where it creates obtuse angle of 142 degrees in the triangle as follows so the distance in the image is shorter than 380,000km.
The purpose of NASA’s OSIRIS-REx spacecraft (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) is to map and return samples from asteroid Bennu, a carbon-rich hunk of rock that might contain organic materials or molecular precursors to life. In other words the mission to figure out where we came from, as asteroids are remnants from the formation of our solar system. The spacecraft is expected to reach its asteroid destination, Bennu, in December 2018, with approach operations starting in August.
Reference:
See earthview photo gallery with web-globe: LiVEARTH[:]