Parker Solar Probe is humanity's first mission to a star.NASA/Johns Hopkins Applied Physics LaboratoryNASA's Parker Solar Probe is about to make its closest approach to the sun.The spacecraft will fly within 3.8 million miles of the solar surface.The spacecraft is collecting essential data that can help inform forecasting models on Earth.The fastest human-made object is hurtling toward the sun at this very moment, approaching speeds of 430,000 mph — and on December 24, it's scheduled to make history.NASA's Parker Solar Probe launched in 2018 and has completed 21 close flybys around the sun.