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Cometary Organics

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Qicheng Zhang. Username: @qicheng.

Planet Mercury reaches inferior conjunction today. While not a "proper" transit as it misses the photosphere by almost half a degree, Mercury's lack of a substantial atmosphere (unlike Venus) makes it extremely dark at high phase angles, which enables SOHO's LASCO C2 coronagraph to see the disk of the planet (~1 px diameter) silhouetted as a black dot against the bright solar corona.