To put things into perspective, Mars, which is relatively close to us in the solar system, is about 34 million miles away. So AJ129 is flying practically “tight parallel parking” distance in terms of interstellar distances.
Yet that is still several thousand times the width of Earth, so we aren’t even close to getting hit. So, despite some alarming press coverage, NASA tweeted out to a concerned citizen (in Spanish) telling them that any cries of armageddon are “a lie.”
AJ129 is thought to be about 0.745645 miles wide (just under 3/4’s of a mile) and has an elliptical orbit, meaning that it roughly intersects with Earth’s orbit about once every 16 years. It’s quite an enterprising little guy and even has its own Wikipedia page!
You can see for yourself just how close AJ129 is coming to us by checking out the white oval here compared to Earth’s orbit in blue:
Source: Big Think