The statement that the Korolev crater on Mars was only just discovered is not accurate. The Korolev crater was actually discovered in the 1960s by the Soviet Union's Mars probe, Mars 3, which was part of the Mars program. It was named after Sergei Korolev, a prominent Soviet rocket engineer and spacecraft designer.
The reason it might appear as if the crater was only recently discovered is that our understanding of Mars has significantly improved over the years as more missions have been sent to the planet. Early missions, such as Mars 3, provided limited data and imagery of Mars, and the resolution of the images was relatively low.
In recent years, with the advancements in technology and the arrival of more sophisticated probes and orbiters, we have been able to obtain higher-resolution images and more detailed data about the surface of Mars. This has allowed us to better analyze and identify various features, including the Korolev crater.
So, while the Korolev crater was indeed discovered several decades ago, our current knowledge and understanding of it have been enhanced by more recent missions and improved imaging capabilities.