Before it crashes, Cassini may solve one of the greatest mysteries of Saturn’s rings.
Cassini has nine months before it will make a final, fatal plunge into Saturn’s atmosphere. In the 20 years the craft has been in space, it has seen storms on Saturn’s surface, sent a probe down to its moon Titan, and shown us the eerie beauty of Saturn’s hexagonal north pole. As it is rapidly running out of fuel, it’s been given one last mission: to solve the mystery of the planet’s rings.
“We’re uncertain by quite a large margin about how much stuff is really there [in the rings],” Preston Dyches, a NASA spokesperson for the Cassini mission, says. “That has major implication for how they formed and how old they are. That’s still one of the biggest mysteries of Saturn — how did it get these rings — which tells us things about how planets form and how planets form around other stars.”
Studying Saturn’s rings helps scientists understand how planets and solar systems form. It’s likely the Earth and all the planets in our solar system formed out of a ring of gas and debris around the sun.
To solve the mystery, Cassini has recently begun a series of unprecedented and perilous “ring grazing” orbits. Cassini’s “grande finale,” as NASA is calling it, might be its most impressive feat to date.
Cassini will spend its final months getting an unprecedented look at Saturn’s rings
Cassini goes offline in September 2017. Until then, it will undergo two sets of ring-grazing orbits.
Up first: On November 30, Cassini began the first of 22 orbits that get very close to the planet’s outer rings. The orbits bring Cassini to the outer edge of the rings. There, it will study the density of these outer rings and the small moons that exist near them. This is what the orbits look like: