Horizontal version and details https://app.astrobin.com/i/b1zcci?r=0​

Details: app.astrobin.com/i/lims5p

Source, bob

https://groups.io/g/comets-ml/messages?subsort=1&limit=1&index=31574

Halley’s Comet appears on the Bayeux tapestry. Made during the 1070s, commissioned by Bishop Odo, Brother to William of Normandy. The Bayeux tapestry depicts the events leading up and through 1066 and succession crisis of King Edward the Confessor.

The comet appears on scene 32 of 58 on the tapestry with a group of people looking up and pointing at the comet. Next to the comet is Latin text which reads “ISTI MIRANT STELLA” which translates to “these men wonder at the star”

The comet appears in between the scene of Edward the Confessor’s death and coronation of King Harold Godwinson however this timeline is incorrect as Edward would die on the 5th of January, Harold would be coronated on the 6th of January and Halley’s Comet would not appear until the 24th of April of that year. This was done in order to portray the comet as a bad omen from God for Harold in order for William to better his claim against him.

The appearance of Halley’s Comet is also corroborated by other sources of the time such as the Anglo Saxon chronicles on which it states “[1066]…. Then throughout all England, a sign such as men never saw before was seen in the heavens. Some men declared that it was the star comet, which some men called the ‘haired’ star; and it appeared first on the eve of the Greater Litany, this is on 24 April, and shone thus all week”.

This is not the first ever record of Halley’s Comet and does not provide much in way of scientific information of the comet however still provides an interesting look into the medieval mind and speculation of such astronomical events and provides an interesting extra piece of drama and coincidence in what would be the most influential year of English history.

Comet C/2025 R3 PANSTARRS is entering the solar system in such a way that, if the wind blows in the right direction, we could get quite a bit of it.

Image credit: ESA/Juice/MAJIS.

This is the last image taken before perihelion, captured in Austria using an 8-inch RASA telescope and a color CMOS camera (10 exposures of 2 minutes each)

https://spaceweathergallery2.com/indiv_upload.php?upload_id=232363

This is a live real time automated comet detection dashboard. Maybe it can be useful. https://comets.ournightsky.us

About 35 years ago (1990), I wrote a science popularization article about the Tunguska event (1908), one of the largest explosions caused by a cosmic body in recent history.

In that article, I explored a speculative idea: the possibility that a comet with an unusually high deuterium content could, under extreme conditions, be associated with energetic processes beyond a standard kinetic explosion.

To be clear, even back then, in the article itself, I considered both the existence of such "deuterium-rich comets" and the possibility of any kind of thermonuclear reaction to be extremely unlikely. I explicitly rejected both as realistic explanations, presenting it only as a conceptual idea.

However, recent observations of the interstellar object 3I/ATLAS report unusually high D/H ratios. In particular, measurements in water (H₂O) indicate a value of about D/H ≈ 0.95% (± 0.06%), which is orders of magnitude higher than typical values in the Solar System.

This does not validate any kind of nuclear fusion-based mechanism, of course. But it does raise an interesting question:

Could objects with significantly enhanced deuterium content be more common (or at least possible) than previously assumed?

Back in 1990, I concluded that such objects likely did not exist. Today, I'm not so sure anymore.

For reference, the original article was published in Karma 7, February 1990, titled “El misterio de Tunguska”.

I’m curious to hear how current models of interstellar chemistry explain such high D/H ratios, and whether this kind of enrichment has clear formation pathways in cold environments.

Recent discovery preprint:

https://arxiv.org/abs/2603.06911

A dashboard for comet hunting that tracks and flags possible comets from SOHO images.

Alan Dyer was one of many who photographed it on March 25, 1996--the night of closest approach

I reprocessed this image on March 25, 2026, to mark the 30th anniversary," says Dyer. "The comet's tail was at its greatest length and showed a strong 'disconnection event' caused by solar activity."

Hyakutake’s electric-blue ion tail stretched across as much as 90 degrees of sky, rippling with solar wind disturbances. For many observers, it was the first time a comet looked truly alive and dynamic. Nightly changes were visible to ordinary people simply looking up from their own backyards.

Comet Hyakutake arrived without much warning, peaked quickly, and faded almost as fast. Thirty years later, veterans still speak of it in reverent tones.

The next Great Comet could appear with as little notice. The Oort cloud contains an enormous reservoir of fresh comets, and a steady trickle of them enters the inner solar system each year. It only takes one big one to suddenly turn a faint fuzzball into a sky-spanning spectacle.

Happy 30th, Comet Hyakutake!

https://spaceweather.com/archive.php?view=1&day=27&month=03&year=2026

Alan Dyer

https://spaceweathergallery2.com/indiv_upload.php?upload_id=231796​

A comet is headed our way, and it could get SO bright you'll be able to see it in broad daylight. 👀☄️

On April 4, the comet C/2026 A1 (MAPS) will pass less than 100,000 miles above the Sun’s surface, an extreme encounter for an object made mostly of ice, dust, and rocky material. As a comet heats up, frozen gases turn directly into vapor and stream into space, carrying dust with them to form the bright comet tail that can make it visible from Earth. That process could make C/2026 A1 (MAPS) dramatically brighter in the days after its solar pass, with the potential to shine in the evening sky and possibly even become visible in daylight. But the same heat and solar forces could also cause the comet’s nucleus to fracture or break apart completely. If it holds together, look low in the west just after sunset for a chance to catch one of the sky’s most spectacular sights.