Category Astronomy/Space

Comet Impacts Formed Continents when Solar System Entered Arms of Milky Way

New Curtin research has found evidence that Earth’s early continents resulted from being hit by comets as our Solar System passed into and out of the spiral arms of the Milky Way Galaxy, turning traditional thinking about our planet’s formation on its head.

The new research, published in Geology, challenges the existing theory that Earth’s crust was solely formed by processes inside our planet, casting a new light on the formative history of Earth and our place in the cosmos.

Lead researcher Professor Chris Kirkland, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences, said studying minerals in the Earth’s crust revealed a rhythm of crust production every 200 million years or so that matched our Solar System’s transit through areas...

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New Water Map of Mars will Prove Invaluable for Future Exploration

Water-rich minerals at Jezero Crater
Water-rich minerals at Jezero Crater

A new map of Mars is changing the way we think about the planet’s watery past, and showing where we should land in the future.

The map shows mineral deposits across the planet and has been painstakingly created over the last decade using data from ESA’s Mars Express Observatoire pour la Mineralogie, l’Eau, les Glaces et l’Activité (OMEGA) instrument and NASA’s Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument.

Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts.

On Earth, clays form when water interacts with rocks, with...

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Grains of Dust from Asteroid Ryugu Older than our Solar System

Grains of dust from Asteroid Ryugu older than our solar system
(a) Backscattered electron (BSE) image of Ryugu thin section A0058-2. Every black area consists of ∼20 NanoSIMS maps measured. (b) An area in section C0002 with a less altered lithology than the surrounding Ryugu matrix (“clast 1”; BSE image). This area contains Mg-rich olivine, low-Ca pyroxenes, and spinel grains with sizes up to ∼15 μm (Kawasaki et al. 2022). Two of three O-anomalous grains identified in Ryugu, including one likely presolar silicate (g)–(h), were found in this region. (c)–(e) Secondary electron (SE) image of a Ryugu particle pressed into gold foil in which two presolar SiC grains were detected. The C-anomalous regions, indicated by the white arrows, are clearly associated with 28Si hotspots. (f) 17O-rich presolar oxide found in the Ryugu A0058-2 matrix...
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Astronomers Solve the Case of Missing Carbon Monoxide in Protoplanetary Disks

Credit Required: M.Weiss/Center for Astrophysics | Harvard & Smithsonian

Astronomers frequently observe carbon monoxide in planetary nurseries. The compound is ultrabright and extremely common in protoplanetary disks—regions of dust and gas where planets form around young stars—making it a prime target for scientists.

But for the last decade or so, something hasn’t been adding up when it comes to carbon monoxide observations, says Diana Powell, a NASA Hubble Fellow at the Center for Astrophysics, Harvard & Smithsonian. A huge chunk of carbon monoxide is missing in all observations of disks, if astronomers’ current predictions of its abundance are correct.

Now, a new model—validated by observations with ALMA—has solved the mystery: carbon monoxide has been hiding in ice format...

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