The universe loves to confuse us. And sometimes, the discoveries that benefit science the most are those that leave us severely confused and scrambling for crazy explanations.
1 The Moon’s Mysterious Magnetic Field
The Moon has remained magnetically inert for eons, but new research confirms that this was not always the case. Over four billion years ago, an inner molten moon-core whirled against a lunar mantle, much like Earth’s own dynamo, and a potent magnetic shield extended from the Moon. But this was presumably a much weaker version than Earth’s, since the satellite obviously lack’s Earth’s heft, right?
Surprisingly, our scrawny little moon was actually able to generate a mightier field than ours. No one knows why such a puny body displayed such potent magnetic activity, with current answers running the gamut from “we don’t know” to “magic?” The mystery reveals that there’s yet another unknown set of variables regarding our most intimately studied partner. It appears the early Moon took advantage of some exotic method to produce its awesome magnetic field. And it managed this for longer than astronomers previously thought was possible, perhaps due to constant meteor impacts that fueled Luna’s magnetism.
It appears that the field disappeared sometime around 3.8–4 billion years ago, though more research is necessary to find out exactly why. Surprisingly, studies suggest that the Moon’s core is still at least slightly liquid. So even though the Moon is within reaching distance, we’re constantly reminded that there are many fundamental questions we’ve yet to answer about lunar geology.
2 Galaxies 13 Billion Years Old
The early universe was an approximation of hell—a roiling, opaquely dense stew of electrons and protons. Almost half a billion years passed before the baby universe cooled down enough to allow the formation of neutrons. Shortly thereafter, the universal landscape settled further so that stars and galaxies could come into being.
A recent ultra-deep survey by the Subaru telescope—located in Hawaii and run by the National Astronomical Observatory of Japan—revealed seven of the earliest galaxies ever. Over 13 billion light-years distant, they appeared as unimaginably faint pinpricks of light. In fact, they were visible only after Subaru focused on a tiny patch of sky for over 100 hours of exposure.
Born only 700 million years after the big bang exploded everything into existence, these galaxies are among the earliest things ever observed and are among the first evidence of organization within the universe. These types of galaxies are characterized by intense hydrogen excitation and an absence of heavier elements since metals (other than minute amounts of lithium) hadn’t been blasted into existence yet by supernovae.
Termed Lyman-alpha emitters (LAE), these galaxies appeared suddenly and for (more or less) unknown reasons. LAE galaxies are prolific star-producers, and their extreme age offers insight into the evolution of the universe. However, astronomers aren’t sure if the ones captured by Subaru were newly formed or if they’d been present and were only made visible by a thinning of the cosmic gas that initially obscured them.