LMA image of dual rings of DCO+ encircling the star IM Lup.

LMA image of dual rings of DCO+ encircling the star IM Lup. The rings reveal details about the conditions of this young protoplanetary disk. The existence of the outer disk was surprising, providing new insights into the formation of heavy molecules — those based on deuterium — in this and other similar systems. Credit K. Oberg, CfA; ALMA (NRAO/ESO/NAOJ); B. Saxton (NRAO/AUI/NSF)