This invisible boundary, located about 100 astronomical units (AU) from the Sun (one AU is the distance from Earth to the Sun ...

3I/ATLAS is only the third interstellar object ever detected. You can stream the object live today, or maybe see it from your own telescope!

Watch interstellar comet 3I/ATLAS live online tonight as it races toward the sun on a rare visit from beyond our solar system.

This limit of detectability suggests that the outer solar system might be filled with bodies like them, a massive population that is beyond the visibility of current surveys (Live Science).

Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars.

The European Southern Observatory has captured the clearest images yet of the interstellar visitor 3I/ATLAS as it moves inward through the solar system.