planetesimals tagged posts

Supernova immersion model suggests Earth-like planets are more common in the universe

New supernova theory suggests Earth-like planets are more common in the Universe
Schematic picture of the system assumed in this study. Credit: Science Advances (2025). DOI: 10.1126/sciadv.adx7892

Rocky planets like our Earth may be far more common than previously thought, according to new research published in the journal Science Advances. It suggests that when our solar system formed, a nearby supernova (the massive explosion of a star near the end of its life) bathed it in cosmic rays containing the radioactive ingredients to make rocky, dry worlds. This mechanism could be ubiquitous across the galaxy.

Earth-like planets are thought to form from planetesimals (objects made of rock and ice) that were dried out early in the solar system’s history...

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Super-Earths and mini-Neptunes: More Earth-like planets may exist

illustration of planets

A new study presents a compelling new model for the formation of super-Earths and mini-Neptunes – planets that are 1 to 4 times the size of Earth and among the most common in our galaxy. Using advanced simulations, the researchers propose that these planets emerge from distinct rings of planetesimals, providing fresh insight into planetary evolution beyond our solar system.

A new study by Rice University researchers Sho Shibata and Andre Izidoro presents a compelling new model for the formation of super-Earths and mini-Neptunes — planets that are 1 to 4 times the size of Earth and among the most common in our galaxy...

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To Stick or to Bounce: Size determines the Stickiness of Cosmic Dust Aggregates

Micrometer-scale dust particles from protoplanetary disks, or sites around stars with particles and hydrogen and/or other gasses, aggregate to form planetesimals, or kilometer-scale building blocks of planets. Planetesimals, in turn, merge due to mutual gravity. ©JAMSTEC

Microparticle dust aggregates, which are thought to play a role in the formation of new planets, are less likely to stick together after a collision when the aggregates are larger.

Current evidence suggests that microparticles of cosmic dust collide and stick together to form larger dust aggregates that may eventually combine and develop into planets...

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Where did Earth’s Water come from? Not Melted Meteorites, according to scientists

The dashed white line in this illustration shows the boundary between the inner solar system and outer solar system, with the asteroid belt positioned roughly in between Mars and Jupiter. A bubble near the top of the image shows water molecules attached to a rocky fragment, demonstrating the kind of object that could have carried water to Earth. Credit: Jack Cook/Woods Hole Oceanographic Institution. Click image to download hi-res version.

Water makes up 71% of Earth’s surface, but no one knows how or when such massive quantities of water arrived on Earth.

A new study published in the journal Nature brings scientists one step closer to answering that question...

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