European Space Agency and NASA’s Solar and Heliospheric Observatory observed a bright comet plunging toward the sun at nearly 1.3 million miles per hour on August 3–4, 2016. Like most sungrazers, it was torn apart and vaporized by the intense heat and forces near the sun.
ESA/NASA/SOHO/Joy Ng
What is a sungrazer comet?
Comets are balls of ice and dust that orbit the sun. “When they come into the inner solar system, the sun heats them and starts to vaporize them,” says Mihos. “The tail of the comet is the ice on the comet’s surface being vaporized and leaving behind a trail of gas and dust.”
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Kreutz sungrazers are a particular class of comet—ones thought to have originated from a larger comet that broke up centuries ago—characterized by very elongated orbits. While they spend most of their time far away from the sun, they eventually plunge through the sun’s outer atmosphere, called the corona, at very high speeds. Here, temperatures often reach 2 million degrees Fahrenheit— conditions that can quickly tear apart an object made largely of ice.
Why are comets so unpredictable?
Comets are inherently unstable objects thanks to their loosely bound composition. As they approach the sun and begin to vaporize, their structure shifts—altering how they spin, shed material, and move through space. That constant change makes their behavior difficult to predict.
“Comet C/2026 A1 is a little bit special in the sense that of all the Kreutz-class comets that have been identified, it was discovered farthest from the Sun,” says Mihos. “In other words, we can watch it coming in and see how it behaves as it gets nearer and nearer to the Sun.”