Ceres Probably Formed Farther out in the Solar System and Migrated Inward

When Sicilian astronomer Giuseppe Piazzi spotted Ceres in 1801, he thought it was a planet. Astronomers didn’t know about asteroids at that time. Now we know there’s an enormous quantity of them, primarily residing in the main asteroid belt between Mars and Jupiter.

Ceres is about 1,000 km in diameter and accounts for a third of the mass in the main asteroid belt. It dwarfs most of the other bodies in the belt. Now we know that it’s a planet—albeit a dwarf one—even though its neighbours are mostly asteroids.

But what’s a dwarf planet doing in the asteroid belt?

Continue reading “Ceres Probably Formed Farther out in the Solar System and Migrated Inward”

Protoplanetary Disks Throw Out More Material Than Gets Turned Into Planets

When a young solar system gets going it’s little more than a young star and a rotating disk of debris. Accepted thinking says that the swirling debris is swept up in planet formation. But a new study says that much of the matter in the disk could face a different fate.

It may not have the honour of becoming part of a nice stable planet, orbiting placidly and reliably around its host star. Instead, it’s simply discarded. It’s ejected out of the young, still-forming solar system to spend its existence as interstellar objects or as rogue planets.

Continue reading “Protoplanetary Disks Throw Out More Material Than Gets Turned Into Planets”

Exoplanetary System Found With 6 Worlds in Orbital Resonance

200 light-years away from Earth, there’s a K-type main-sequence star named TOI (TESS Object of Interest) 178. When Adrian Leleu, an astrophysicist at the Center for Space and Habitability of the University of Bern, observed it, it appeared to have two planets orbiting it at roughly the same distance. But that turned out to be incorrect. In fact, six exoplanets orbit the smallish star.

And five of those six are locked into an unexpected orbital configuration.

Continue reading “Exoplanetary System Found With 6 Worlds in Orbital Resonance”

The Sun Might Have Once Had a Binary Companion Star

For some time now, astronomers have known that the majority of systems in our galaxy consist of binary pairs rather than individual stars. What’s more, in recent decades, research has revealed that stars like our Sun are actually born in clusters within solar nebulas. This has led to efforts in recent years to locate G-type (yellow dwarf) stars in our galaxy that could be the Sun’s long-lost “solar siblings.”

And now, a new study by Harvard astronomers Amir Siraj and Prof. Abraham Loeb has shown that the Sun may once have once had a very similar binary companion that got kicked out of our Solar System. If confirmed, the implications of this could be groundbreaking, especially where theories on how the Oort Cloud formed and whether or not our system captured a massive object (Planet Nine) in the past.

Continue reading “The Sun Might Have Once Had a Binary Companion Star”

The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago

The Milky Way has a number of satellite galaxies; nearly 60 of them, depedending on how we define them. One of them, called the Sagittarius Dwarf Spheroidal Galaxy (Sgr d Sph), may have played a huge role when it comes to humans, our world and our little civilization. A collision between the Milky Way and the Sgr d Sph may have created the Solar System itself.

Continue reading “The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago”

We Know We’re Made of Stardust. But Did it Come From Red Giants?

We’ve all heard this one: when you drink a glass of water, that water has already been through a bunch of other people’s digestive tracts. Maybe Attila the Hun’s or Vlad the Impaler’s; maybe even a Tyrannosaurus Rex’s.

Well, the same thing is true of stars and matter. All the matter we see around us here on Earth, even our own bodies, has gone through at least one cycle of stellar birth and death, maybe more. But which type of star?

That’s what a team of researchers at ETH Zurich (Ecole polytechnique federale de Zurich) wanted to know.

Continue reading “We Know We’re Made of Stardust. But Did it Come From Red Giants?”

Some of Earth’s Gold Came From Two Neutron Stars That Collided Billions of Years Ago

For about a century now, scientists have theorized that the metals in our Universe are the result of stellar nucleosynthesis. This theory states that after the first stars formed, heat and pressure in their interiors led to the creation of heavier elements like silicon and iron. These elements not only enriched future generations of stars (“metallicity”), but also provided the material from which the planets formed.

More recent work has suggested that some of the heaviest elements could actually be the result of binary stars merging. In fact, a recent study by two astrophysicists found that a collision which took place between two neutron stars billions of years ago produced a considerable amount of some of Earth’s heaviest elements. These include gold, platinum and uranium, which then became part of the material from which Earth formed.

Continue reading “Some of Earth’s Gold Came From Two Neutron Stars That Collided Billions of Years Ago”