The solar system does not end neatly at Neptune’s orbit. This episode reveals the vast, invisible structure of icy debris beyond the known planets, shaped by gravity and time. From scattered objects ...

The eighth and most distant planet from the sun, Neptune, reaches opposition with the sun on Sept.23, when it will be in its best position for viewing for the year. Neptune is too faint to see with ...

The trans-Neptunian object nicknamed Ammonite moves across the sky over several hours in May 2023. Its diameter is estimated to be between about 135 and 235 miles. NAOJ / ASIAA Astronomers have just ...

Neptune takes 16 h 6 min 36 s (0.6713 days) to complete a single sidereal rotation, and 164.8 Earth years to complete a single orbit around the Sun. This means that a single day lasts 67% as long on ...