The Universe Can't Hide Behind the Zone of Avoidance Any Longer

By Brian Koberlein - November 18, 2023 01:35 PM UTC | Cosmology
The Solar System sits within the galactic plane, so it was once impossible to look past the core of the Milky Way through countless stars and clogging dust to the distant cosmos. This region was called "The Zone of Avoidance." But those days are over. While visible light is blocked, infrared and radio can pierce through the region, revealing galaxies on the far side of the Milky Way. Astronomers are finding thousands of previously hidden galaxies behind the core.
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The Oort Cloud Might be More Active Than We Thought

By Brian Koberlein - November 13, 2023 01:43 PM UTC | Planetary Science
Astronomers have seen meteors strike the Earth on hyperbolic trajectories for decades; they would have escaped the Solar System if our planet hadn't gotten in the way. They could have come from other solar systems, but an interstellar meteorite has never been found. Instead, these might be coming from the Oort Cloud, perturbed by a rogue planet or star passing close to the Solar System. It might be happening more often than we thought.
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If You Account for the Laniakea Supercluster, The Hubble Tension Might Be Even Larger

By Brian Koberlein - November 11, 2023 11:22 AM UTC | Cosmology
When you measure the Universe's expansion rate to relatively nearby galaxies against the expansion rate in the cosmic microwave background radiation, the numbers don't agree, and their error bars don't overlap. This is the Hubble Tension. A new paper suggests the difference might be even greater by 2-3% (1.1 km/s/Mpc) when you account for the gravitational effect from the Laniakea supercluster, which dominates the gravity in our part of the Universe.
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If We Could Find Them, Primordial Black Holes Would Explain a Lot About the Universe

By Brian Koberlein - November 10, 2023 01:49 PM UTC | Black Holes
As far as we know, black holes can only be formed by the death of massive stars, but a persistent theory says that black holes of all masses could have formed directly in the early Universe. These primordial black holes would help explain several mysteries in astronomy: outlier mergers of black holes, dark matter, and young supermassive black holes. How are they different from stellar mass black holes, and what upcoming instruments could detect them?
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