Question Your World: What’s the First Thing to Visit Us from Outside Our Solar System?

Posted: November 2, 2017

For a long time now, humanity has looked up at the stars and wondered if we would ever be visited. Well, we just were. What's the first thing to visit us from outside our solar system?

Astronomers around the world have been paying attention to an unexpected visitor from beyond our solar system. No, sadly, it’s not aliens. This exciting visit is from an asteroid from another planetary system.

Scientists have been observing an object a little less than a quarter of a mile wide that is currently cruising through our celestial backyard. For now, the object is being called A/2017 U1.

By tracing the object’s path and speed of travel, scientists have determined that this is the first ever object observed to come from beyond our solar system.  A pretty awesome astronomical first and all of us are alive to learn more about what’s out there!

On October 14, this object came as close to the Earth as it’s going to get, about 15 million miles away from us.  This distant traveler is only going to be in our solar system for a relatively short time because it’s flying through super, super fast. How fast is it going? Consider that the Voyager 1 spacecraft, which is on its way out of the solar system, is traveling at just over 10 miles per second. This fast-traveling foreign object is moving through interstellar space at about 16 miles per second (over 57,000 miles per hour!), too quickly to be held by the Sun’s gravity, so it swung around our star on a hyperbolic path and will never return. 

Image credit: Getty Images

So, why is it here? Scientists have studied models and done the math to understand the early days of our solar system. They've discovered that gas giants like Jupiter, Uranus, and Neptune were not always where they are now. As a solar system and its planets develop, motion and migration begins to happen. Motion of big objects like planets can cause some dust and rock debris to be flung around and sometimes even ejected out of the solar system altogether. That's how it worked here, giving a hint as to how other solar systems potentially form too. Perhaps this distant traveler was ejected out of its initial home stellar system and has been drifting through space, as it will continue to do after its quick pass through our solar system.

While it’s in our neck of the cosmic woods, scientists are studying it as much as possible to determine all the various details of this object in order to better classify it and to further understand the natural world that surrounds us.

Stay tuned as more studies are done on this foreign traveler by real scientists and of course those Ancient Aliens guys, too.