Star Trek: 10 Strangest Space Anomalies You May Have Forgotten
3. Graviton Ellipses
A graviton ellipse was the first spatial anomaly ever officially encountered by humanity.
During one of Earth's earliest crewed missions to Mars in 2032, the Ares IV spacecraft was sucked into a graviton ellipse that appeared suddenly out of subspace and, with no sign of the vessel or it's pilot Lieutenant John Kelly, both were assumed lost. In reality, Kelly and the Ares IV were transported into the anomaly, where they were found, centuries later, by the crew of Voyager in the episode One Small Step.
Voyager was able to learn from Lieutenant Kelly's logs that he didn't die immediately when he impacted with the anomaly, as Starfleet suspected, but actually survived for quite some time inside the "eye of the storm," where he learned the existance of aliens from observing their lost vessels and died knowing that humanity's early struggle to reach towards the stars would one day be worth it.
The Voyager crew retrieved his remains and gave him a proper funeral, and the anomaly disappeared back into subspace.