1) The Earth's core is hotter than the surface of the Sun.

2) The recent advancements in space exploration include missions to Mars by various space agencies, such as NASA's Perseverance rover landing on Mars in 2021, aiming to explore the planet's geology and search for signs of past microbial life.

3) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

4) The first smartphone, the IBM Simon, was introduced in 1992 and featured a touchscreen, email capabilities, and apps such as a calendar and calculator.