Spacecraft Flies Through Dusty Tail of Exploded Comet in Unique Chance Encounter

A comet that broke apart in advance of it was thanks to surface in Earth’s night sky past yr has now however specified us a scarce and excellent reward.

As its disembodied tail continued its journey via the Photo voltaic System, a spacecraft orbiting the Solar was equipped to pass by its tail, fairly by possibility. The European Area Agency’s Solar Orbiter has now offered us a exceptional glimpse into the tail of a disintegrated comet.


The results have been introduced at the Royal Astronomical Society’s National Astronomy Conference 2021.

Comet C/2019 Y4 (ATLAS) was uncovered in December of 2019, and immediately comet-watchers were fired up. Its path all-around the Sunshine was anticipated to choose it close enough to Earth to be obvious with the bare eye. Ahead of it could get to that issue though – and extended prior to its predicted perihelion – the comet disintegrated.

010 comet(NASA/ESA/STScI/D. Jewitt, UCLA/CC BY 4.)

Above: Hubble Area Telescope graphic of comet C/2019 Y4 (ATLAS) on April 20 2020, providing the sharpest watch to date of the break up of the sound nucleus of the comet.

In April of past year, images from the Hubble Space Telescope showed the fragments of the comet, shattered as its ices sublimated in the growing warmth drawing nearer to the Sunshine. This is not basically an unusual prevalence, but it did fairly dash our hopes of comet-viewing.

There were being other hopes pinned on C/2019 Y4 (ATLAS), way too. Not extended just after it released, the Photo voltaic Orbiter workforce noticed that its route would convey it as a result of the comet’s tail. The spacecraft wasn’t made for this kind of face, and nor ended up its instruments meant to be switched on at this issue, but the researchers figured why not try out to see what they could?


When the comet disintegrated, the group figured that, since they experienced currently geared up, they might as properly adhere to via with their strategies, even nevertheless there may be nothing to detect. Nonetheless, when Photo voltaic Orbiter made its planned rendezvous with the cometary tail, it did without a doubt detect one thing.

Now experts have reconstructed the encounter to find out accurately what the probe detected.

“We have discovered a magnetic industry construction observed at the beginning of June 4th 2020, linked with a total magnetic subject reversal, a neighborhood deceleration of the stream and huge plasma density, and enhanced dust and energetic ions situations,” write a workforce led by physicist Lorenzo Matteini of College College or university London.

“We interpret this framework as magnetic subject draping all over a low-discipline and large-density object, as anticipated for a cometary magnetotail. Within and about this large-scale structure, numerous ion-scale fluctuations are detected that are dependable with modest-scale waves and buildings generated by cometary select-up ion instabilities.”

In other words, Photo voltaic Orbiter’s instruments detected the magnetic discipline of the comet’s tail, embedded in the ambient interplanetary magnetic area. This authorized them to understand extra about C/2019 Y4 (ATLAS)’s ion tail.


Comets, you see, have two tails. There’s the dust tail that 1 is made up of dust ejected by the comet as icy content sublimates, making a dusty atmosphere termed a coma all around the cometary nucleus. Radiation pressure from the Solar and the photo voltaic wind pushes dust absent, forming a tail.

The ion tail, on the other hand, is generated when solar ultraviolet light-weight ionizes molecules in the coma. The ensuing plasma generates a magnetosphere it is also pushed absent by the solar wind, and that is the ion tail.

The team’s final results confirmed that the magnetic field of the ion tail stays for a time just after the comet disintegrates. The magnetic industry embedded in the photo voltaic wind then bends and drapes all around the magnetic industry of the ion tail.

The probe’s measurements, they stated, are reliable with an face with a cometary magnetic and plasma construction embedded in the solar wind, possibly involved with a fragment of the damaged comet, or a part of the tail that was formerly disconnected.

“This is pretty a unique celebration, and an exciting option for us to examine the make-up and construction of comet tails in unprecedented element,” Matteini stated.

“With any luck , with the Parker Solar Probe and Solar Orbiter now orbiting the Sunshine closer than at any time prior to, these events might become substantially additional frequent in long run!”

The results have been introduced at the National Astronomy Assembly 2021.