There’s So Much Pressure at the Earth’s Core, it Makes Iron Behave in a Strange Way

New observations of the atomic structure of iron reveal it undergoes "twinning" under extreme stress and pressure. Image Credit: SLAC National Accelerator Laboratory

It’s one of nature’s topsy-turvy tricks that the deep interior of the Earth is as hot as the Sun’s surface. The sphere of iron that resides there is also under extreme pressure: about 360 million times more pressure than we experience on the Earth’s surface. But how can scientists study what happens to the iron at the center of the Earth when it’s largely unobservable?

With a pair of lasers.

Continue reading “There’s So Much Pressure at the Earth’s Core, it Makes Iron Behave in a Strange Way”

The Early Solar System was Messier and More Violent Than Previously Believed

This artwork shows a rocky planet being bombarded by comets. Image credit: NASA/JPL-Caltech

Our conventional models of planet formation may have to be updated, according to a pair of new papers.

Accretion is the keyword in current planet formation theory. The idea is that the planets formed out of the solar nebula, the material left over after the Sun formed. They did this through accretion, where small particles accumulate into more massive objects. These massive boulder-sized objects, called planetesimals, continued to merge together into larger entities, sometimes through collisions. Eventually, through repeated mergers and collisions, the inner Solar System was populated by four rocky planets.

But the new research suggests that the collisions played out much differently than thought and that objects collided with each other several times, in a series of hit and runs, before merging. This research fills some stubborn holes in our current understanding.

Continue reading “The Early Solar System was Messier and More Violent Than Previously Believed”

Many Sunlike Stars Gobbled up Some of Their Planets

New research shows that other sunlike stars in our galaxy aren’t so kind to their planets. Up to a quarter of them may consume planets before they even establish a solar system. That consumption leaves behind a distinct chemical fingerprint in the stars, which can help researchers understand how common planetary systems are…and how often they get destroyed.

Continue reading “Many Sunlike Stars Gobbled up Some of Their Planets”

This is how you get Tatooines. Binary Star Planet Formation

One of the less appreciated aspects of George Lucas’ vision for Star Wars was that he predicted the existence of planets in binary star systems years before we saw even the first exoplanet.  Now a team from the University of Cambridge and the Max Planck Institute for Extra-terrestrial Physics have found how exactly those planets can form without being torn apart by their accompanying suns.

Continue reading “This is how you get Tatooines. Binary Star Planet Formation”

The Sun is Mellow Yellow Today. Billions of Years Ago? Not So Much

Planetary formation theory has been undergoing a lot of changes recently, with an ever expanding litany of events that can potentially impact it.  Everything from gravity to magnetic fields seems to impact this complex process.  Now scientists want to add another confounding factor – massive solar flares thousands of times more powerful than the most powerful we have ever observed from the Sun.

Continue reading “The Sun is Mellow Yellow Today. Billions of Years Ago? Not So Much”

Does Mercury Have a big Iron Core Because it’s so Close to the Sun’s Magnetic Field?

Magnetic fields are great for lots of things – directing explorers, levitating trains, and containing nuclear fusion reactions are just an example of what these invisible forces can do.  Now we can ascribe another feature to magnetic fields – they can give planets a rocky core.

Continue reading “Does Mercury Have a big Iron Core Because it’s so Close to the Sun’s Magnetic Field?”

Astronomers see an Accretion Disk Where Planets are About to Form

Planet formation is notoriously difficult to study.  Not only does the process take millions of years, making it impossible to observe in real time, there are myriad factors that play into it, making it difficult to distinguish cause and effect.  What we do know is that planets form from features known as protoplanetary disks, which are made up of gas and dust surrounding young stars.  And now a team using ALMA have found a star system that has a protoplanetary disk and enough variability to help them nail down some details of how exactly the process of planet formation works.

Continue reading “Astronomers see an Accretion Disk Where Planets are About to Form”

Planets may Start Forming Before the Star is Even Finished

An illustration of a protoplanetary disk. Planets coalesce out of the remaining molecular cloud the star formed out of. Within this accretion disk lay the fundamental elements necessary for planet formation and potential life. Credit: NASA/JPL-Caltech/T. Pyle (SSC) - February, 2005
An illustration of a protoplanetary disk. Planets coalesce out of the remaining molecular cloud the star formed out of. Within this accretion disk lay the fundamental elements necessary for planet formation and potential life. Credit: NASA/JPL-Caltech/T. Pyle (SSC) - February, 2005

Planets form from the accumulation of countless grains of dust swirling around young stars. New computer simulations have found that planets begin forming earlier than previously thought, when a planet’s star hasn’t even finished forming yet.

Continue reading “Planets may Start Forming Before the Star is Even Finished”

Magnetic Fields Help Shape the Formation of New Planets

In all of scientific modeling, the models attempting to replicate planetary and solar system formation are some of the most complicated.  They are also notoriously difficult to develop.  Normally they center around one of two formative ideas: planets are shaped primarily by gravity or planets are shaped primarily by magnetism.  Now a new theoretical model has been developed by a team at the University of Zurich (UZH) that uses math from both methodologies to inform the most complete model yet of planetary formation.

Continue reading “Magnetic Fields Help Shape the Formation of New Planets”