Skip to main content
24 votes
Accepted

What caused this mysterious stellar occultation on July 10, 2017 from something ~100 km away from 486958 Arrokoth?

There were three attempts to measure Arrokoth by occultation, and the June 3rd attempt didn't detect anything. The July 10th attempt had a tiny blip, that appeared to be in the "wrong place"...
James K's user avatar
  • 125k
21 votes

How and when will Sirius migrating towards the Sun trigger the movement of Kuiper belt objects into the solar system?

Probably never. It will make its closest approach in about 64,000 years at a distance of about 7.86 light years. That's not a huge difference from its current distance of about 8.7 light years. I'm ...
12 votes

What caused this mysterious stellar occultation on July 10, 2017 from something ~100 km away from 486958 Arrokoth?

According to Wikipedia: A preliminary analysis of all collected data suggested that Arrokoth was accompanied by an orbiting moonlet about 200–300 km (120–190 mi) away from the primary. It was later ...
Pierre Paquette's user avatar
11 votes
Accepted

Strange speck of light in the picture sequence of the approach to 2014 Mu69 (Ultima Thule)

It's probably a cosmic ray strike, a common artifact on New Horizons images. The image, however, is of very poor quality which makes it difficult to analyse the exact nature of the spot. I'll go ...
Alex Hajnal's user avatar
  • 1,199
10 votes

Why isn't Eris considered a planet despite being the body of dominant mass?

You are correct that the IAU definition of "clearing the orbit" has the problem of being not explicitly quantified. And a complete clearing was obviously never the intention behind the definition. I ...
SpaceCore's user avatar
  • 3,441
10 votes
Accepted

What does the Sun look like from Eris at its aphelion?

Light flux decreases as one over distance squared. So if Eris is 100 times further away from the Sun than the Earth is, then the amount of light that reaches Eris is 10 000 less than that on Earth. ...
usernumber's user avatar
  • 17.6k
8 votes

Could stellar occultations be used to survey Kuiper belt objects?

Yes this is possible and has been tested by the TAOS (Transneptunian Automated Occultation Survey) group among others. That group is in the process of building the TAOS-II project which will use ...
astrosnapper's user avatar
  • 8,432
8 votes
Accepted

Is Planet Nine shepherding the Kuiper Belt?

Estimates of Planet 9's orbit currently suggest that it doesn't have any major effect on the Kuiper Belt, because its orbit is too far away and on a different plane than the Kuiper belt, and from the ...
bandybabboon's user avatar
  • 4,268
8 votes
Accepted

How does 2015 RR245 compare to the other KBOs predicting "Planet 9"?

It was the first thing I thought too, but I would say it won't count in the statistics. The earlier paper by Batygin & Brown was talking about bodies orbiting further out. 2015 RR245 orbits ...
Andy's user avatar
  • 2,477
8 votes

Which measurements have shown that 2014 MU69 is red? (New Horizons' next target)

This was a hard one to answer, primarily because of the difficulty in tracking down information. The Observations of MU69 The extended mission for New Horizons involved adjusting its orbit to do a ...
zephyr's user avatar
  • 15k
7 votes
Accepted

Would it be practical to map out the Kuiper Belt and Oort Cloud via Radar?

An answer can perhaps be given in terms of the capabilities of the now defunct Arecibo radar facility. This was the most powerful radar system, as summarised in Venditti et al. (2023). Arecibo had a ...
ProfRob's user avatar
  • 155k
6 votes
Accepted

Could rocks from Earth have reached the Kuiper belt, or Neptune at least? If so, how?

(I have tracked down the reference that I made in my comment on the question.) Presumably earth rocks once blasted into space (by volcanism or meteorite impact) gain or lose energy primarily by ...
antlersoft's user avatar
  • 3,455
6 votes
Accepted

Orbital period for a 1 light year object?

To answer this, let's visit Kepler's third law which tells you the orbital period of a body, if you know how far away it is. $$\frac{P^2}{a^3} = \mathrm{constant}$$ As it turns out, if you use the ...
zephyr's user avatar
  • 15k
5 votes

Is there an established distinction between a geyser and a cryovolcano in solar system bodies?

An educated guess: on Earth, the working fluid in a "geyser" is water, which remains a fluid more or less permanently after each eruption. This means that geyser eruptions are not associated with ...
rob's user avatar
  • 1,021
5 votes
Accepted

Observed data: Why so many MPECs about TNOs lately?

This is the result of a new way to investigate the images taken by the PanSTARRS survey, see Weryk et al. 2016. A second batch of new discoveries was issued on July 26. This has been planned for ...
Daniel Bamberger's user avatar
4 votes
Accepted

How many Kuiper Belt objects have moons? How do we know this?

"Moons" is a misnomer here, the majority of Kuiper Belt Objects (KBOs) with companions are binaries. Now there are several populations in the Kuiper Belt, characterized by their ...
AtmosphericPrisonEscape's user avatar
4 votes
Accepted

Which measurements have shown that 2014 MU69 is red? (New Horizons' next target)

While the answer by @zephyr is extensive, unresolved images of a very distant Kuiper belt object distant body over a short arc of it's orbit through a single filter can not be used to calculate a ...
uhoh's user avatar
  • 30.7k
3 votes
Accepted

Is there Kuiper belt/Oort cloud like structure in gas giants?

The gravitational region around the planets isn't hard to calculate, sometimes called the Sphere of Influence, sometimes called the Hill Sphere. They're calculated differently but they define pretty ...
userLTK's user avatar
  • 24.1k
3 votes
Accepted

Kuiper belt planet formation

The Kuiper Belt is fairly large (with inner and outer radii $\sim30\text{ AU}$ and $\sim50\text{ AU}$), but it does not contain much mass. The total mass is likely somewhere between $0.01$ and $0.1$ ...
HDE 226868's user avatar
  • 37k
3 votes
Accepted

What is the farthest reported distance from observer from which a solar system body has occulted a star?

Wikipedia lists some of the most farthest objects from the sun in the solar system. The third farthest object "Eris" was the subject of one of the most distant stellar occultations observed ...
Nilay Ghosh's user avatar
  • 4,694
2 votes
Accepted

The Kuiper Belt and Oort cloud

How come the comets and asteroids in the Kuiper belt and Oort cloud are kept in a gravitational field and they don't get pushed and pulled by the planets around them? Basically, they're so far away ...
Glorfindel's user avatar
  • 4,800
2 votes

Where will the frost line be when the Sun becomes a red giant and what effect will it have on the solar system?

The current solar constant on the frost line is equal to: $$j_c=\frac{\sigma T_c^4 \cdot 4\pi r_c^2}{4\pi R_c^2}=\frac{\sigma T_c^4 r_c^2}{R_c^2}$$ where $T_c$ is the current effective temperature, $...
User123's user avatar
  • 2,879
2 votes

Is the mass of Kuiper belt dominated by large objects?

It depends on what you call large. There may be hundreds of thousands of icy bodies larger than 100 km (62 miles) and an estimated trillion or more comets within the Kuiper Belt. But the total mass of ...
Natsfan's user avatar
  • 4,504
2 votes
Accepted

Are there actual asteroids in the Oort cloud?

Tl;Dr: It is a matter of consideration if you want to call Kuiper belt bodies/Oort cloud bodies "asteroids" or not. Long answer: The Oort cloud defines the cosmographic boundary of the Solar ...
Nilay Ghosh's user avatar
  • 4,694
2 votes
Accepted

Which kind of strategy should we take to discover Planet 9 and other KBOs?

This question already discusses the challenges of discovering planet 9 The main problem of the hypothetical planet 9 as compared to Sedna and 2012 VP113 is: Sedna and 2012 VP113 have orbits that ...
CKA's user avatar
  • 287
2 votes

Why is the Kuiper belt called like this?

Compiling my comments into an answer. Kuiper belt is a "belt" because majority of the bodies reside in the ecliptic plane and relatively low inclination. There are handful of exceptions but ...
Nilay Ghosh's user avatar
  • 4,694
1 vote
Accepted

Are there any known low-inclination trans-Neptunian objects?

Queries to the JPL Small Body Database or the ESA Asteroids Dynamic Site for such bodies return several results. Some of the bigger ones are: Centaurs with H < 10 and i < 4° 386968 (2012 BR61), ...
Mike G's user avatar
  • 18.7k
1 vote

If the hypothetical planet beyond the Kuiper belt exists, is it likely there are even more planets farther outside?

As with so many things, it's complicated. Depending on your definition of a planet (and for the sake of argument, we'll just assume that the definition of a planet is a stellar body that roughly ...
GrasshopperTaji's user avatar
1 vote

Are there recent estimates of Kuiper belt mass?

Surprisingly, I also have not been able to find any generally recent (5 years or less ago) information about this topic. I did find a research paper from 2007 (Here). You may want to check out page ...
MystaryPi's user avatar
  • 364

Only top scored, non community-wiki answers of a minimum length are eligible