Some of this stuff is known as mysterious darkmatter, others are things like dark comets, which as their name suggests, are far more difficult to see from Earth than something like ...
Taking advantage of a cosmic 'double lens,' astronomers resolved more than 40 individual stars in a galaxy so far away its light dates back to when the universe was only half its present age.
"Up to this year, most observations were consistent, with dark energy being the cosmological constant. Nonetheless, 2024 was full of hints pointing out this might not be the case." ...