Celestial Extremely eccentric minor planet to visit inner solar system this decade

Heliobas Disciple

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Extremely eccentric minor planet to visit inner solar system this decade
By Michael Irvin
June 20, 2021
A diagram of the orbit path of 2014 UN271, which will make its closest pass in 2031

A diagram of the orbit path of 2014 UN271, which will make its closest pass in 2031


The outskirts of our solar system is teeming with mysterious objects – and now one of them is heading our way. Astronomers have discovered a minor planet that’s about to make its closest pass to the Sun on its 600,000-year orbit.

The object in question is designated 2014 UN271, and it was only recently identified in data from the Dark Energy Survey captured between 2014 and 2018. Size estimates place it anywhere between 100 and 370 km (62 and 230 miles) wide. If it’s a comet, it’s quite a big one, especially for one coming from the outer solar system.

“[That] puts it on a similar scale, if not larger than, Sarabat's huge comet C/1729 P1, and almost undoubtedly the largest Oort Cloud object ever discovered – almost in dwarf planet territory!” says Sam Deen, a citizen astronomer, in a post on the Minor Planet Mailing List (MPML) forum.

But by far the most intriguing thing about 2014 UN271 is its orbit around the Sun. This thing is extremely eccentric, journeying between the inner solar system and the Oort cloud that marks the boundary of interstellar space over a period of 612,190 years.

And it turns out, astronomers are about to witness the closest pass of this incredible round trip. Currently, 2014 UN271 is about 22 Astronomical Units (AU) from the Sun (for reference, Earth is 1 AU from the Sun). That means it’s already closer than Neptune, at 29.7 AU. And it’s not stopping there – it’s already traveled 7 AU in the last seven years, and at its closest in 2031, it’s expected to pass within 10.9 AU of the Sun, almost reaching the orbit of Saturn.

Before then, it’s expected to develop the characteristic coma and tail of a comet, as icy material on its surface vaporizes from the heat of the Sun. This close pass would give astronomers an unprecedented close look at Oort cloud objects.

Unfortunately for us amateurs on the ground, don’t expect to see a show on the scale of Halley’s comet. While it’s too early to tell for sure, Deen calculates that 2014 UN271 would, at best, become about as bright as Pluto in the night sky, but more likely it’ll reach the brightness of Pluto’s moon Charon. Still, we’ll probably get some amazing shots from telescopes and observatories of the time.

After its close pass, 2014 UN271 will then hurtle back out into the inky blackness, on a several-hundred millennia return trip to the Oort cloud, and an incredible peak distance of almost 60,000 AU.

Sources: JPL Solar System Dynamics, Minor Planet Center, MMPL forum
 

Heliobas Disciple

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EMPHASIS NOT MINE (it's in the original article)


HUGE COMET DISCOVERY: Astronomers have just discovered a comet so big, it might actually be a minor planet. The object is named 2014 UN271. Astronomers Pedro Bernardinelli and Gary Bernstein found it in archival images from the Dark Energy Survey. It appears to be about 100 km wide, 2 or 3 times bigger than record-breaking Comet Hale-Bopp of the 1990s.


Above: A discovery image (inset) and orbit of huge comet 2014 UN271.

Now for the bad news. Although 2014 UN271 is falling toward the sun, we may never see it with our naked eyes. At closest approach in early 2031, the behemoth comet will be just outside the orbit of Saturn, too far for naked-eye viewing. Some astronomers are estimating a maximum brightness near magnitude +17, about the same as Pluto's moon Charon.

It's still an amazing discovery. 2014 UN271 has an extremely elongated orbit stretching from ~the neighborhood of Saturn out to a staggering distance of almost a light year. At the far reaches of its orbit, 2014 UN271 barely feels the sun's gravity and could be snatched out of the Solar System altogether by the ephemeral pull of galactic tides. Discovering such a traveler during its brief time among the planets is very lucky indeed.

There is talk of a space mission to intercept 2014 UN271. The European Space Agency is building a probe called Comet Interceptor designed to investigate comets coming from deep space. It, or something like it, might be able to visit 2014 UN271 a decade from now.

With an object like this, we have to expect surprises. 2014 UN271 certainly poses no threat to Earth, but it could brighten more (or less) than expected. Multiple groups of astronomers have already detected signs of out-gassing even though 2014 UN271 is still beyond Uranus. Early signs of activity may bode well for future visibility through small telescopes if not the unaided eye.

To learn more about this object, we encourage reading the Twitter feed of co-discoverer Pedro Bernardinelli.
 

packyderms_wife

Neither here nor there.
Dramatic effect! Keep everybody looking up.

ten years ago they wouldn't said anything publicly about this event happening, it would have been buried in the bowels of some astronomy journal never to see the light of day for fear of spooking the sheep. Now we're hearing about it and only because it has a very slim chance of entering the inner solar system and plowing into the Sun. The beginning of the last Solar Cycle a huge comet plowed into the Sun and it went from very active to mysteriously quite.
 
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