- Neutrino (Wikipedia)
A neutrino (/njuːˈtriːnoʊ/ new-TREE-noh; denoted by the Greek letter ν) is an elementary particle that interacts via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles (excluding massless particles). The weak force has a very short range, the gravitational interaction is extremely weak due to the very small mass of the neutrino, and neutrinos do not participate in the electromagnetic interaction or the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected.
- Messier 28 (Wikipedia)
Messier 28 or M28, also known as NGC 6626, is a globular cluster of stars in the center-west of Sagittarius. It was discovered by French astronomer Charles Messier in 1764. He briefly described it as a “nebula containing no star… round, seen with difficulty in 31⁄2-foot telescope; Diam 2′.”
![With an apparent magnitude of 7.7, the [Messier 28] cluster appears as a faint patch of light through a pair of binoculars. Large telescopes can resolve its individual stars more effectively.](https://pinchy.cc/commons.wikimedia.org/wiki/M28_-_HST-U-V-IR.jpg/description-1-2/){kind=link}