Scientists captured a repeating fast radio burst (FRB), the second ever seen, which could help unravel the mystery of these enigmatic ultrastrong, ultrabright radio signals.
In September 2018, Astronomers found an unusual infrared signal from a neutron star, likely caused by a dust disk, but the explanation remains unclear.
Saturn's moon Hyperion is a strange, irregular rock with numerous craters and a particle beam of static electricity flowing out into space, as observed by NASA's Cassini spacecraft.
The universe's strongest substance is created from the remains of a dead star, where the pressure can be so high that protons and neutrons become tangled and can resist 10 billion times the force needed to shatter steel.
Hubble Space Telescope spotted a quasar from the early universe and used it to estimate the universe's expansion rate, which suggested that it is expanding faster today than it was back then, conflicting with other measurements and leaving physicists puzzled.
Moonmoons, theoretical submoons orbiting moons, have been dubbed the latest astronomical craze by the internet, with recent calculations suggesting their potential existence.
Tabby's star, which initially confounded astronomers with its strange dips in brightness, is now believed to be surrounded by an abnormal ring of dust causing the phenomenon.
A high-energy neutrino detected by the IceCube Neutrino Observatory in Antarctica in September 2017 provided astronomers with information on its origin, having been flung at Earth by a flaring blazar 4 billion years ago.
Researchers initially thought a galaxy contained little to no dark matter, but subsequent work showed it did contain dark matter, albeit in lower quantities, which paradoxically supported an alternative theory that dark matter may not exist.
The ghostly, ultradiffuse galaxy DGSAT 1, which is nearly invisible due to its thinly spread out stars, sits alone and is believed to be a living fossil from just 1 billion years after the Big Bang.