We present a new IRAC , Spitzer IRAC images of the HH 34 outflow .
These are the first images that detect both the knots along the southern jet and the northern counterjet ( the counterjet knots were only detected previously in a long slit spectrum ) .
This result removes the problem of the apparent coexistence of a large scale symmetry ( at distances of up to \sim 1 pc ) and a complete lack of symmetry close to the source ( at distances of \sim 10 ^ { 17 } cm ) for this outflow .
We present a quantitative evaluation of the newly found symmetry between the HH 34 jet and counterjet , and show that the observed degree of symmetry implies that the jet production region has a characteristic size < 2.8 AU .
This is the strongest constraint yet derived for the size of the region in which HH jets are produced .