Open clusters like Orion have low fertility rate

While a Hubble Space Telescope image of visible light emitted by a protoplanetary disk in the Orion Nebula called proplyd 170-337 shows hot, ionized gas (red) surrounding and streaming off of a disk (yellow), 1.3 mm radio observations by CARMA and SMA reveal the dust disk hiding within the hot gas (contours). This protoplanetary disk has a mass more than one hundredth that of the sun, the minimum needed to form a Jupiter-sized planet. (Bally et al 2000/Hubble Space Telescope & Eisner et al 2008/CARMA, SMA)