Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff, Lauren bob Obam. Here lurking near the orbit of Jupiter is an asteroid like no other. It's an alien from another star system. This visitor may have arrived at our solar system billions of years ago and didn't buy a return ticket. It's now a permanent resident, trying to blend in. Alas blending in is hard to do when you're orbiting the Sun the wrong way, it's also a possible sign
that the asteroid wasn't born here. It was first discovered in twenty fourteen by astronomers working at the Leakala Observatory on Maui and given the designation twenty fifteen b Z five h nine. It's since been given a Hawaiian name, Eavela,
and is affectionately called Bezed. To understand why Bezed's retrograde orbit is a old hill sign that it isn't from round these parts, we first must realize why the planets all orbit the same way around the Sun. Our star was born from a dense region inside a stellar nursery also known as a molecular cloud, as the gas and dust clumped together under gravity to spark the first nuclear
reactions that would become our sun. The cloud spun increasingly faster around that protostar as the material collapsed of physical consequence of the conservation of angular momentum. Over time, a protoplanetary disk of material formed, all spinning in the same direction. Everything that was born from this disc, all of our planets and asteroids, orbited in the same direction like clockwork. Buta orbits the wrong way, a sign that's something strange
is afoot. And it's not just the asteroids retrograde orbit that reveals that it came from another star. It's also the length of time that it's been living in that orbit. For the article, this episode is based on How Stuff Works. Spoke with fatid Na Muni, an astronomer at the Cote Diazor Observatory in France and the lead author of a study looking into the asteroids orbit that was published in
twenty eighteen. He said, it's not the fact that the asteroid now has a retrograde orbit that makes it of interstellar origin. It's the fact that it had the same orbit four point five billion years ago. That is the only evidence, and it is incontrovertible. Namuni and co author Helena Morris of Sal Paulo University in Brazil ran sophisticated computer simulations of BEZ to figure out that it was likely captured over four and a half billion years ago by the gravity of our young son when it was
starting to evolve with its stellar siblings. They found that it wasn't just an asteroid born from the Sun's protoplanetary disc that was gravitationally disturbed by a massive planet and flipped into retrograde orbit. Nope, it had to come from outside the Solar System, and like a gravitational catcher's mit, the Sun caught the interstellar orphan and adopted it as
its own. More I said in a press statement. Asteroid immigration from other star systems occurs because the Sun initially formed in a tightly packed star cluster where every star had its own system of planets and asteroids. The close proximity of the stars, aided by the gravitational forces of the planets, help these systems attract, remove and capture asteroids from one another. There are a handful of known retrograde objects in our Solar System, and the researchers think that
alab isn't the only one. To have originated from another star. During the earliest epoch of our solar system, many asteroids were likely transferred from star to star, and the researchers are in the process of identifying other interstellar adoptees that were captured by our solar system and have orbits near
massive Jupiter. Namuni said, from our work, we see that if objects similar to be Z were captured by Jupiter at the same time and had slightly different orbits, they do not stay with Jupiter like BEZ for four and a half billion years. They tend to leave Jupiter's orbit and go beyond Neptune and assume polar orbits, that is,
orbits that are perpendicular to the ecliptic. We are currently studying the known asteroids of that type to see if we can link them to be Z. A one exciting thing about Okavleb is that it's staying local and thus could be a potential target for a future spacecraft mission. If we could directly sample material from BEZ, we could study the composition of an ancient exoplanetary system. In doing so, we might learn surprises about the evolution of our own planet.
For example, depending on whether we found water with a similar isotopic composition to Earth's water on the asteroid, we might be able to figure out whether interstellar asteroids contributed to the delivery of water to our planet, a discovery that may have profound implications for the origins of life on Earth. Although exciting, some experts aren't convinced of Beza's interstellar beginnings, arguing that it might instead be an extinguished
comment whether or not it's truly interstellar. More research is needed to study its chemical composition, perhaps via a sample return mission, to see whether it's made from the same material that's seated our solar system billions of years ago. Today's episode is based on the article and alien asteroid's been lurking in our solar system since the beginning on
houstofworks dot com. Written by Ian O'Neill. Brainstuff is production of iHeartRadio in partnership with Hastuffworks dot Com and is produced by Tyler klang A. Four more podcasts from my heart Radio. Visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.