Largest Comet Outburst Leaves Dust Trail That Looks Like an Hourglass

The dust trail from the largest comet outburst ever is set to grace the skies this summer, estimated to be in July, and is predicted to be in the shape of an hourglass.

The comet 17P/Holmes let off a huge flash of gas and dust in October 2007, which brightened by a factor of a million and briefly became the latest object in the Solar System by having a dust cloud that has a diameter bigger than the Sun. Planetary scientist Maria Gritsevich from the University of Helsinki in Finland thought that the particles would simply disperse, but that did not happen.

About Comet 17P/Holmes

Edward Holmes regularly observes the Andromeda galaxy (M31), which is why he knows the region very well. But on the evening of Nov. 6, 1892, he saw something different. According to Cometography, it was a comet with a coma of 5 arc minutes across and a bright nucleus.

He was able to identify its location on Nov. 7 before the clouds could have blocked his view. He immediately reported his findings to his colleagues who also tried finding it and fortunately saw the comet with their naked eyes.

Comet 17P/Holmes is a periodic comet that has an orbital period of 6.88 years in which its orbit takes it from 2.05 AU out of 5.02 AU from the Sun.

According to the European Space Agency (ESA), the comet passed through its perihelion at 2.053 AU from the Sun and 2.77 AU in May 2007. Since then, the distance has been increasing from the Sun as the Earth tries to catch up while orbiting closer to the former.

But on the night between Oct. 23 to 24, 2007, the comet made an unexpected sight in the night sky. The largest comet outburst was brightened by a factor of several hundred thousand. That means the comet can now be readily seen by the naked eye envelopes by a fuzzy cloud in the constellation of Perseus.

It was not clear what caused its outburst, but scientists hypothesized that the sudden outgassing or release of particles from the nucleus must have been responsible for the cosmic event.

Dust Trail From Comet 17P/Holmes Set to Grace the Skies on July

Gritsevich and her colleagues designed a new model of the comet's dust trail that shows it persisted instead of simply dispersing, Space.com reported. The dust trail zing in an elliptical orbit between the original outburst point and a point at the opposite side and can now be seen from the Southern Hemisphere.

This year, the parts are beginning to accumulate near the outburst point, making it visible from the Northern Hemisphere. The combined observations from the North and South helped scientists to trace the path of the dust trail over time.

Due to the gravity and solar wind, the particles have to sort themselves by size and generally arrive at the two nodes in their orbit that give it a subtle hourglass shape with two bulges of dust on either side and a narrowed zone in the middle.

The particles are tiny and measure about a fraction of a millimeter in size, and are able to reflect the light of the Sun and making them visible as a fuzzy trail in the night sky. Gritsevich told Live Science that Northern Hemisphere observers may get a chance to see the trail in late July once the particles come out of the Sun's glare.