Finding the sweet spot for submillimetre observations

Observations by telescopes such as ALMA are made in a part of the electromagnetic spectrum called the millimetre. Images taken at shorter wavelengths are clearly sharper, but there are limits to the signal we can process. The line indicates the sweet spot: the shortest possible wavelength where digitization of the signal is still possible. Currently, this lies in the submillimetre regime. In 2024, researchers obtained the highest angular resolution observations ever taken from the ground, at 0.87 millimetres. 

This animation was originally produced for an ESO Chasing Starlight episode on the sharpest ground-based observations yet.