Webb Weighs an Early Twin of the Milky Way

By Brian Koberlein - December 13, 2024 02:24 PM UTC | Extragalactic
Astronomers have used JWST to weigh a galaxy in the early Universe, finding that it has roughly the same mass as the Milky Way should have had at the same time in the Universe's history. The galaxy was seen in a gravitational lens and contains a collection of star clusters, so astronomers have nicknamed it the "Firefly Sparkle Galaxy." The galaxy also contains companion dwarf galaxies, similar to the Milky Way's Magellanic Clouds, which probably merged with it.
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Do the Fastest Spinning Pulsars Contain Quark Matter?

By Brian Koberlein - December 13, 2024 11:40 AM UTC | Stars
When a massive star dies as a supernova, it can leave behind a pulsar, a rapidly spinning neutron star. The fastest pulsars can spin upwards of 700 times a second, blasting out regular pulses of energy. In a new paper, researchers propose that the fastest-spinning pulsars could contain quark matter in their cores. This would be even denser matter than neutrons and help explain how surprisingly massive neutron stars can spin so rapidly, maybe reaching 1,000 Hz.
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Early Earth's Oceans of Magma Accelerated the Moon's Departure

By Brian Koberlein - December 12, 2024 10:50 AM UTC | Planetary Science
When the Earth was struck by a Mars-sized planet in its early history, it ejected a debris cloud that led to the formation of the Moon. In the beginning, the Moon was extremely close to the Earth, but then conservation of angular momentum led to the Moon drifting away from the Earth - it's still doing it today. Because the Earth was covered in oceans of magma, researchers think the Moon moved quickly away from the Earth, getting to 25 Earth radii within 100,000 years.
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Cosmology is at a Crossroads, But New Instruments are Coming to Help

By Brian Koberlein - December 05, 2024 11:48 AM UTC | Cosmology
Thanks to Hubble, JWST, and the Planck mission, we're starting to see cracks in the current ideas in cosmology, expressed by the Hubble Tension, the Cosmic Shear Tension, and the role dark energy plays in the expansion of the Universe over time. Good news: powerful new instruments are already surveying the Universe and should measure any deviations from the widely held cosmological models. It's a fun time to be an astronomer.
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MeerKAT Confirms the Gravitational Wave Background of the Universe in Record Time

By Brian Koberlein - December 04, 2024 02:42 PM UTC | Cosmology
Astronomers are collecting evidence for the gravitational wave background of the Universe, caused by merging supermassive black holes. Now, the MeerKAT radio telescope has confirmed the discovery first made by the NANOGrav experiment, but in a third of the time. For the last five years, MeerKAT has monitored dozens of millisecond pulsars once a week, detecting subtle changes in their radio emissions as gravitational waves flow by.
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Maybe Venus Was Never Habitable

By Brian Koberlein - December 04, 2024 11:02 AM UTC | Planetary Science
The planetary science community argues back and forth about when Venus was last habitable. Did it lose its oceans billions of years ago, or more recently? A new paper suggests that Venus has been a hellscape for its entire history. No oceans, ever. This result comes from the ratio of atmospheric chemicals and how quickly they're replenished by volcanic outgassing. On Earth, volcanic eruptions are mostly steam from interior water, but on Venus, they're 6% water at most.
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White Dwarfs Could Have Habitable Planets, Detectable by JWST

By Brian Koberlein - December 03, 2024 11:28 AM UTC | Exoplanets
White dwarfs are dead stars like our Sun. Although they're no longer performing fusion in their cores, they're still hot and putting out radiation that could support life. A new paper calculates that a white dwarf could support planets in a new habitable zone for 7 billion years, providing the right temperature and radiation to support a biosphere. They're also small and dim, which makes it easier to study planets in orbit around them for potential biosignatures.
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What's Inside Uranus and Neptune? A New Way to Find Out

By Brian Koberlein - December 02, 2024 11:24 AM UTC | Planetary Science
Uranus and Neptune are "ice giants," containing chemicals like methane and ammonia, but compressed under intense pressure. This is just speculation from a couple of flybys with Voyager 2 and telescope observations. A new paper suggests that Uranus and Neptune have distinct layers, which don't easily mix and could explain their unusual magnetic fields. Below the cloud layers is a deep ocean of water and then a compressed fluid of carbon, nitrogen, and hydrogen.
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Interstellar Objects Can't Hide From Vera Rubin

By Brian Koberlein - November 30, 2024 10:50 AM UTC | Planetary Science
When the Vera Rubin Observatory comes online in a few months, it'll be the most effective asteroid and comet hunter ever built. And not just the homegrown variety, Rubin will discover interstellar objects like Oumuamua and Borisov passing through the Solar System. A new paper suggests the kinds of machine learning algorithms that will have the best chance of uncovering these fast-moving objects as they move through the field of view from night to night.
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