This Fireball Ignored the Solar System’s One-Way Signs

Trilobites A meteoroid that grazed the night sky over Australia in 2017 took a very unusual path away from Earth. It’s not unusual for meteors to illuminate night skies over southwestern Australia’s desolate landscapes. But the fireball of July 7, 2017, was different. For a full minute and a half, it just kept burning and burning and burning.

The object carved a trace of light as wide across as Texas, then faded. Many meteors disintegrate in our atmosphere, or slow down and crash into the soil. But after its light show, this one kept going, departing our planet with a celestial “thanks, but no thanks. ” Next stop: Jupiter, at the beginning of 2025.

And after tangling with that giant planet’s gravity, it will most likely be ejected into interstellar space, said Patrick Shober, a graduate student at Curtin University in Western Australia who led a team that studied the event. The July 2017 event is known as a grazing fireball, a rare type of meteoroid that hits Earth’s atmosphere at a low angle, then skims like a skipping stone on a lake. Some are legendary, like 1783’s Great Meteor, which streaked past England and over continental Europe, or the incorrectly named Great Comet of 1860, which was painted by the Hudson River School artist Frederic Church and inspired a poem by Walt Whitman. The first grazing fireball to be studied by modern science zipped over North America for 101 seconds in 1972.

But few spend this long dipping into the atmosphere. And not one has ever been as well studied. It might have gone unseen if not for the Desert Fireball Network, a set of observatories that span a vast, sparsely populated swath of Australia. The network’s goal is to fetch meteorites that land in the desert.

“We see a lot of things that people don’t see because we put the cameras in places where we can find the rock,” Mr. Shober said. But in this case, there was nothing to retrieve.

“His team estimates the rock responsible for the event entered the atmosphere weighing 130 pounds and measuring only about a foot across.”