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A 1980s space telescope may have seen planet nine

gizmodo.com

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Re: A 1980s space telescope may have seen planet nine

#91

Post by netcraft »

tiahura wrote: post #89

Can anyone explain how we’re able to detect dozens of exoplanets (Wiki says we’re up to 4864!), but not be able to detect every large boulder around our own star?

There are two main ways we detect exoplanets. The primary way that I believe accounts for the vast majority of planets we have detected is the transit method. Basically we watch the light from a star very closely and look for a dip in the amount of light coming from it as a planet transits in between us and the star. This of course depends on the planet to pass directly between us and the star, and that means that its ecliptic plane has to be directly edge on with us. The second method is that we are able to detect minor wobbles in a star that infers that there is a planet sized object that is perturbing the star. I believe this is only able to detect Jupiter sized objects up to brown dwarves or other stars though, and even that depends on the distance to the star, and I believe only when the planet orbits at a relatively close distance (I believe closer than the kuiper belt)

The problem in both cases as it relates to planet 9 is that you arent detecting the planet as much as its effects. If you take any planet that far away from a star and youre trying to detect either the very little bit of light that it might be reflecting or its infrared heat signature if youre lucky, but both are incredibly dim.

Re: A 1980s space telescope may have seen planet nine

#92

Post by largbae »

tiahura wrote: post #89

Can anyone explain how we’re able to detect dozens of exoplanets (Wiki says we’re up to 4864!), but not be able to detect every large boulder around our own star?

Most of the exoplanets that we detect today are very large and orbit very close to their star, and happen to pass between us and the star during their orbit. This is why they are often referred to as "hot jupiters". We see them by seeing the dimming effect on the star as they transit between us, and we need to see a few tramsits to be sure that we are looking at an orbiting object and what orbital period it has.

There are just a mind-boggling number of stars out there, making 5,000 hot jupiters a small number.

Re: A 1980s space telescope may have seen planet nine

#93

Post by AareyBaba »

_Microft wrote: post #31
starwind wrote: post #2

Relevant part: For the recent work, [Michael] Rowan-Robinson redid his search from nearly 40 years ago and found three points in the data from late summer 1983 that indicate some object moving across the sky. The data sources sit low on the galactic plane, though, meaning that the satellite was taking the data through plenty of dusty, cloudy material that can emit infrared light. In other words, the work is something…

Isn’t that bigger news than it sounds at first? Part of the problem of finding planet nine must be knowing where it currently is on its orbit. A few possible observations should help to narrow down the space in which to look for it by a lot (rather: would make it almost clear where it currently is). Maybe JWST could be of help with testing the hypothesis that these early infrared observations of a moving object were…

Finding it may be complicated if it is hiding behind a cloaking device.

Re: A 1980s space telescope may have seen planet nine

#94

Post by netcraft »

kibwen wrote: post #73
nsf39k wrote: post #42

Earlier quoted context omitted.

The technology and infrastructure needed to reach Planet 9, build a mining outpost, then transport everything back at a profitable cost is likely decades if not centuries away. That’s not counting the fact that Planet 9 is so far away that getting there with current technology is a lengthy affair in itself (the New Horizons probe wouldn’t even be halfway to a theoretical Planet 9, and it’s been flying for over 15 yea…

> likely decades if not centuries away The fastest man-made object ever launched was the New Horizons spacecraft. Headed on an intercept course for Pluto 30 AUs away, it took 9.5 years to get there. And that's without slowing down; if you actually wanted to land on Pluto you would need to spend even more time actually slowing down. The object in the OP is 225 AU away (which is dramatically closer than prior estimates…

I dont mean to take away anything from your post - but wanted to mention that the parker solar probe has now beat new horizons for fastest man made object (if you don’t count the manhole cover :) )

Re: A 1980s space telescope may have seen planet nine

#96

Post by Hallucinaut »

tectonic wrote: post #3

Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appear skewed by the invisible gravity of a possible Planet Nine, accounting for observation bias, and running a ton of simulations and MCMC, they concluded: if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth masses and a perihelion (closest approach to…

Love the newsletter by the way. It's the only one out of dozens I receive that I actually read every time.

I can recommend anyone that has an interest in anything space related to give it a read.

Re: A 1980s space telescope may have seen planet nine

#97

Post by sounds »

rand0mx1 wrote: post #90
ziddoap wrote: post #11

Earlier quoted context omitted.

He's always quick on these, and always with quality videos. Anyone with an interest in space who has not watched any of Anton's videos are seriously missing out.

His videos are unnecessarily long

The most vital information is presented and explained in the first 30 seconds of the video.

Re: A 1980s space telescope may have seen planet nine

#98

Post by flir »

bink wrote: post #67
zionic wrote: post #64

Earlier quoted context omitted.

I’m just mad we’re losing out on “Planet X”. When I was a kid Pluto was a planet so the new one was X (10) and it was cool. Now this new planet is just going to be planet 9 again… totally lame.

But it's from outer space.

The .plan thread is four up from here.

Re: A 1980s space telescope may have seen planet nine

#99

Post by robocat »

kbelder wrote: post #27
alex_young wrote: post #19

Earlier quoted context omitted.

An object with multiple Earth masses could hardly be classified as a dwarf planet.

"A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite." According the the wrong-headed AIU definition. So, yes, _Jupiter_ could be a dwarf planet, if it hasn't cleared it's o…

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

Weird definition since it prevents deciding if an exoplanet is a planet or a dwarf planet.

It smells like a compromise proxy measure for: orbital stability, in a reasonably circular orbit, plus rule out Pluto.

Maybe there is some deep reason for using that measure, but it is not obvious.

Re: A 1980s space telescope may have seen planet nine

#100

Post by kibwen »

netcraft wrote: post #94
kibwen wrote: post #73

Earlier quoted context omitted.

> likely decades if not centuries away The fastest man-made object ever launched was the New Horizons spacecraft. Headed on an intercept course for Pluto 30 AUs away, it took 9.5 years to get there. And that's without slowing down; if you actually wanted to land on Pluto you would need to spend even more time actually slowing down. The object in the OP is 225 AU away (which is dramatically closer than prior estimates…

I dont mean to take away anything from your post - but wanted to mention that the parker solar probe has now beat new horizons for fastest man made object (if you don’t count the manhole cover :) )

Indeed, but the Parker Solar Probe is cheating, since it's going so fast because it's literally plummeting into the sun--the exact opposite direction of a deep space probe. :)
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