International astronomers have for the first time witnessed the birth of a planetary system beyond Earth's sun that could one day resemble our own.

Given 3I/ATLAS' highly eccentric orbit, this will be its one and only visit to our solar system, as its trajectory does not loop back around the sun. That's why astronomers around the world are using a wide variety of telescopes to observe the comet during its brief visit, before it returns to interstellar space.

The Gemini North telescope in Hawaii recently snapped a close-up of the comet that's captured the world’s attention.

A team of international astronomers, including a University of Michigan doctoral student, were the first to publish the discovery of just the third known interstellar object to visit our solar system on July 3.

Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's not aliens.)

Harvard astronomer Avi Loeb suggests that if interstellar object 3I/ATLAS isn't a comet, nor an asteroid, it may have been "sent" to us.

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today."

Very few meteorites from this planet ever reach Earth and none have been scientifically proven. A study investigated two stones linked to Mercury.