(CNN) The sun is the literal star of the show in our solar system, but we're still trying to figure out our celestial disco ball.
Debates about the sun were first posed by ancient Greek philosophers. Thousands of years later, the combined work of people like Copernicus, Galileo, Kepler and Newton helped determine that planets orbit the sun.
Many questions about our sun remain, like the nature of the energized wind that streams away from it across the solar system, or why the fiery orb's outer atmosphere is so much hotter than the surface.
It's why NASA sent the Parker Solar Probe on a seven-year mission to investigate in 2018. The spacecraft has already uncovered surprising things.
Now, at its closest approach to the sun yet, we're getting to the good stuff.
It's official: Humans have used a spacecraft to "touch the sun" and revealed some unusual insights about our star.
The Parker Solar Probe successfully flew through the sun's corona, or upper atmosphere, to sample particles and our star's magnetic fields. This NASA goal was 60 years in the making.
Because the spacecraft will continue to draw closer to the sun, especially during an anticipated peak in solar activity, even more surprises are sure to be in store as the mission goes on.
This critter's got legs and knows how to use them. In fact, it has the most legs of any living animal.
It's a true millipede with 1,306 legs. Mille means "thousand" in Latin, but known millipede species topped out at 750 legs until this discovery.
Scientists found the real McCoy living deep underground in Western Australia. It's only 3.7 inches (9.5 centimeters) long, but it has 330 body segments.
In case you're wondering, the researchers recounted the legs, just to be sure.
A previously unknown human population lived on the isolated Faroe Islands hundreds of years before the Vikings arrived -- and researchers found out thanks to ancient sheep poop.
The rugged archipelago, located between Norway and Iceland, was first reached by people who brought livestock with them in 500 AD. The Vikings later arrived in the 800s.
Analysis of sediment cores taken from a lake on one of the Faroe Islands helped researchers establish a timeline of when the non-native sheep, and their human owners, arrived.
The exact identity of these people remains a mystery, but the team has an idea of who they were, thanks to some intriguing clues.
Mars is the scientific gift that keeps on giving. This week, researchers made several groundbreaking discoveries that change our understanding of the red planet.
It turns out that the Perseverance rover has been driving over the remains of ancient volcanic lava for months -- something that was "completely unexpected" for mission scientists.
The rocks that Percy has sampled so far were also found to have interacted with water multiple times, and some of them include organic molecules.
And a European orbiter investigating Valles Marineris on Mars -- picture the Grand Canyon, but 10 times longer, five times deeper and 20 times wider -- found it has "significant amounts of water."
The Arctic is suffering as our planet warms. The typically frozen biome failed its annual health check due to the climate crisis.
More than 100 scientists shared the news in the Arctic Report Card this week. The report tracked changes in sea ice, snow, temperatures, animals and even vegetation, all pointing to the fact that the Arctic is melting.
Meanwhile, researchers warned that a critical ice shelf in Antarctica could shatter within the next five years. Its presence is safeguarding the so-called "Doomsday glacier."
Antarctica's Thwaites Glacier already accounts for about 4% of annual global sea level rise. Irreversible changes throughout the planet could result from its demise.
Keep these facts in your hat for trivia night:
-- These meat-eating dinosaurs could sprint as fast as Usain Bolt -- yet another reason to be glad "Jurassic Park" isn't real.
-- NASA's Juno mission just revealed dreamy new images of Jupiter and the otherworldly sounds of its moon Ganymede.
-- Are neurosurgeons and rocket scientists really smarter than the rest of us? This is what the research team found.
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