[J3L2404]

'From these two observations, physicists have created theories for a new kind of mass and a new kind energy'

There is also gravitational lensing and some others but no direct evidence. IANAP but our not fully understanding gravity and the Flyby and Pioneer anomalies hint at some breakdown of known physics. The first and farthest craft sent by man has a distance anomaly, directed at the sun, hmm. Plus the thought of new laws on gravity is much more exciting than dark matter and there should be a slew of new findings as data analysis gets better so its anyones guess.