Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A dwarf planet coming within 11 AU of the sun over the next 10 years

groups.io

Post reply on HN
Print view View original

171–180 of 330 posts

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#171

Post by sojuz151 »

Fordec wrote: post #125
mcorning wrote: post #13

For reference 1 AU (Astronomical Unit) is about 150 million km. Saturn ranges from being about 7 to 11 AU away from Earth. Voyager 1 is 152 AU away. This object is excitingly close and will be fun to study.

Is it possible to get a probe out that far in time to make a good intercept? I imagine with this (relatively) short notice this is cutting it a bit close to orchestrate a proper orbital insertion by a designed, manufactured and tested program?

Some context: It took Cassini-Huygens 7 years to reach saturn with two venus and one jupiter flyby. It took New Horizons 9 years to reach pluton with jupiter flyby. With Inclination of 95.467° and Argument of perihelion of 326.285° flyby could happen near to Ecliptic but for getting to orbit one would need a nice gravity assist from jupiter.

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#172

Post by TameAntelope »

edgyquant wrote: post #123
grawprog wrote: post #90

Earlier quoted context omitted.

So pretty much between Saturn and Uranus.... Even as an adult that still always makes me chuckle. I can't help it.

It’s pronounced your-uh-ness by pretty much everyone (or your-ah-noose if your going by the greek god and not the Latin copy/paste.)

I prefer to call it the Georgium Sidus!

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#173

Post by lmilcin »

prince781 wrote: post #138
jessriedel wrote: post #53

Earlier quoted context omitted.

Yes, this is an aspect of orbital mechanics that people find unintuitive before they study it. You can't be captured by a planet's gravity alone. If you come in from infinity (i.e., not already captured) you will escape to infinity (remain not captured). The basic idea can be seen from the fact that gravitational dynamics are time-reversible, so if gravity could capture you like this you could also start in orbit aro…

> gravitational dynamics are time-reversible, so if gravity could capture you like this you could also start in orbit around a planet and spontaneously be ejected. I don't have a strong background in physics, and perhaps this is splitting hairs, but is this true if we consider gravitational radiation? Over a very long time a body's orbital energy will be lost to gravitational waves.

It would be like saying all the school children exercises and train timetables are invalid because they don't take into account relativistic effects that obviously are still present at 60mph.

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#174

Post by elihu »

perl4ever wrote: post #124
clajiness wrote: post #17

Earlier quoted context omitted.

> its orbit takes it from just beyond the orbit of Saturn (10.9 AU) all the way out to the Oort Cloud It looks like it currently orbits the sun.

According to the link, the outgoing aphelion will be almost 40% more than the previous one, so I wouldn't assume it's going to orbit indefinitely.

That seems awfully weird. Is that something that things orbiting the sun normally do?

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#175

Post by Koshkin »

bnjemian wrote: post #162

I say we catch that sucker, tow it into our neck of the woods as a second moon, and use it as a space port. Are there a million problems with this proposal? Yes. But would it be totally rad to do this? Also yes.

R-right... What can go wrong?

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#176

Post by mdorazio »

TameAntelope wrote: post #169
c7DJTLrn wrote: post #167

Earlier quoted context omitted.

That's terrifying, no? A whole planet (yes a dwarf one, but still a PLANET) is just rogue and will wander through the orbit of Sol as it pleases.

> I would estimate at an albedo of 0.01-0.08 a diameter of 130-370 kilometers (nominally 160) which 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! So a bit less dramatic but still really cool.

For reference, a nominal 160km diameter would put it around the same size as the 40th largest asteroid known. Huge for an object coming from the oort cloud, but not really huge in comparison to other rocky bodies in the solar system.

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#178

Post by sneak »

bnjemian wrote: post #162

I say we catch that sucker, tow it into our neck of the woods as a second moon, and use it as a space port. Are there a million problems with this proposal? Yes. But would it be totally rad to do this? Also yes.

What sort of propulsion mechanisms (even those that are currently physically plausible but entirely outside our technology, so, for example, solar sails or nuclear torchships, but not, say, warp drive) could possibly be used to achieve such a task?

Re: A dwarf planet coming within 11 AU of the sun over the next 10 years

#180

Post by perl4ever »

elihu wrote: post #174
perl4ever wrote: post #124

Earlier quoted context omitted.

According to the link, the outgoing aphelion will be almost 40% more than the previous one, so I wouldn't assume it's going to orbit indefinitely.

That seems awfully weird. Is that something that things orbiting the sun normally do?

My intuition is that anything with a really eccentric orbit (10s to 10s of thousands of AU) has more of a chance of passing through many gravitational fields that change its orbit.
Post reply on HN