The Chernobyl reactor core did not "melt into" the earth. While there was a meltdown, it wasn't a process of continuous melting downwards. Here's a breakdown of what happened:

* The explosion and fire: The core explosion and subsequent fire released a massive amount of radioactive material into the atmosphere.

* Melting and solidification: The intense heat from the meltdown caused some parts of the core to melt. This molten material then solidified into a dense, radioactive mass called the "lava-like corium."

* Containment: This corium eventually settled in the lower part of the reactor building, forming a "lava lake" in a basement area.

* No "melting into" the Earth: The corium never reached the Earth's crust. It's contained within the destroyed reactor building, covered by a concrete sarcophagus.

So, while the Chernobyl meltdown was a severe accident, the reactor core didn't "melt into" the Earth. It was a localized meltdown that solidified and is now safely contained within the reactor structure.