The epoch of matter-radiation equality, a fascinating era in the evolution of the Universe, leaves a unique imprint on the matter power spectrum, manifesting as a characteristic turnover. This intriguing feature can serve as an alternative standard ruler, the longest in the cosmos, that has the potential to shed light on the Hubble tension. I will present our latest findings derived from the quasar sample of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). Additionally, I will outline our ongoing endeavours to accurately measure this turnover using the cutting-edge Dark Energy Spectroscopic Instrument (DESI) and Euclid.