C/2017 U1 now A/2017 U1

The strange interstellar object has been reclassified. Originally it was thought to be a comet but it never grew tails. Robert Weryk's object is now known called A/2017 U1, as per the Minor Planet Center.

The NASA article shows an animated graphic of the interloper.

The unusual object was measured at 400 meters in diameter. A medium-sized rock.

It was moving remarkably fast outside of the solar system, around 25.5 kilometres per second. That's about the same speed as the Earth as it orbits around the Sun.

It came in from "above" the solar system. On 2 Sep, it passed through the plane of the planets and went inside the orbit of Mercury.

On 9 Sep, it slung around the Sun.

On 14 Oct, it went under the Earth at a distance of approximately 24 million km or 60 LD! Cosmologically, darned close.

It speed up to 44 km/s!