We have a refined estimate for the mass of the neutrino, the most abundant massive particle in the Universe: its mass is 500,000 times less than an electron
Source:
https://www.newscientist.com/article/2224528-the-mystery-of-the-mass-of-the-neutrino-could-soon-be-solved/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home