It is really interesting to see a space craft which is capable of measuring the speeds of stars with high precision.

That's where Gaia comes in. The European Space Agency satellite is designed to measure positions and speeds of about 1 billion nearby stars with unprecedented precision. Its vision is so sharp it should be able to discern the equivalent of a shirt button on the surface of the moon as seen from Earth,

And I also read that MACHO's(Massive Compact Halo Object's) were also considered as a leading contender for dark energ, along with black holes(later ruled out),but only WIMP's are mentioned.

A leading hypothesis posits that dark matter is composed of some kind of exotic particle, yet to be detected, that doesn't interact with light, so we can't see it. One such theorized class of particles is called WIMPs (Weakly interacting massive particles), which are thought to be neutral in charge and weigh more than 100 times the mass of a proton.

Any guesses on what happened to the MACHO theory.