A dark matter asteroid heads for a graviton ellipse
A display showing a dark matter asteroid
A dark matter asteroid was a celestial object composed of dark matter, that emitted electromagnetic radiation.
In 2376, a graviton ellipse being investigated by the USS Voyager was attracted to a dark matter asteroid. The two anomalies collided, causing severe gravimetric distortions inside the ellipse that caused damage to the Delta Flyer. (VOY: "One Small Step")