better than what we can achieve in conventional labs. Third, the system must be as close to absolute zero as possible to avoid decoherence due to the scattering of thermal photons and blackbody radiation. If these pressure and temperature conditions could be attained (in outer space, for instance ), we could consider a matter-wave scattering experiment in a Talbot-Lau interferometer like the one we discussed above in the case of C70. It would be set up such that the collapse time and the travel time between the last grating and the Tabolt point are similar. Then, one could use the mass to tune the ratio C/ttravel between these times. If the ratio is above one (C > ttravel), wave fringes should be observed at the Talbot point; if it is below one, the system would collapse before reaching L, and a Moiré pattern (expected for particles crossing the grating) would be observed.