[HN Gopher] The 'megacomet' Bernardinelli-Bernstein is the find ...
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The 'megacomet' Bernardinelli-Bernstein is the find of a decade
Author : wglb
Score : 262 points
Date : 2021-09-08 15:32 UTC (7 hours ago)
(HTM) web link (www.space.com)
(TXT) w3m dump (www.space.com)
| cl42 wrote:
| Wikipedia link for those who want more detail:
| https://en.wikipedia.org/wiki/C/2014_UN271_(Bernardinelli-Be...
| aunty_helen wrote:
| The important bit:
|
| > It will make its closest approach to Earth around 5 April
| 2031 at a distance of 10.11 AU
|
| The sad bit:
|
| > Once at perihelion, the comet is not expected to get brighter
| than Pluto (mag 13-16)... Even if it reaches the magnitude of
| Pluto, it will require about a 200 mm telescope to be visually
| seen
| vikingerik wrote:
| For reference, 10 AU is the distance of Saturn's orbit,
| that's why so dim, it's really not coming near the sun at
| all.
| malfist wrote:
| For those more familiar with photography than astronomy,
| 200mm referrers to the aperture of the telescope, not the
| focal length. This is a telescope roughly 8 inches in
| diameter.
|
| If you're looking to see it, Orion's XT8 would be a great
| starting telescope with aperture enough to see the comet
| ASalazarMX wrote:
| 200mm are 7.9 inches. Are the focal length and the diameter
| roughly the same?
| [deleted]
| malfist wrote:
| Nope. Focal length is how far the light has to travel,
| diameter is the aperture, or how big the opening is to
| collect light.
|
| The XT8 telescope I references has an 8 inch aperture,
| and a 1200mm focal length
| carl_dr wrote:
| Not at all, my 9.25" telescope has a focal length of
| about 2.4 metres - a focal ratio of f/10.
|
| You'll recognise f/x from camera lenses and such.
|
| The diameter does control how much light the telescope
| "swallows" though, you'll need a larger telescope to see
| less bright objects (or longer exposures, although when
| you are using your eye, that has a limit of course!)
|
| So in this case, the post about is saying you'll need
| something about 200mm diameter to see the comet. Anything
| smaller, and you're just not getting enough light to see
| it.
| pbhjpbhj wrote:
| Sounds close enough in distance and far enough away in time
| that we could muster a robot intercept mission; would that be
| likely to be useful enough to warrant the cost?
| d_silin wrote:
| Yes, and there have been (unofficial) proposals. With SLS
| or Starship as launch vehicle a fast intercept mission is
| feasible within 10 years and no corners cut on mission
| design.
| codezero wrote:
| This is super cool. I studied comets for a while when I was in
| academia, and my favorite was one called Humason [0]. There are
| other great photos of it, some in google images, though the ones
| I had in the research lab in a a few books about comets were even
| more surprising. It had a very odd tail appearance because the
| comet tail is primarily created by an interaction with the solar
| wind / magnetic field, and at distances far from the Sun, that
| field is much weaker, so the tail becomes less straight, and this
| effect is even more pronounced when the comet is very large, as
| smaller comets just don't have an easy to detect visible tail
| from such great distances from Earth.
|
| Humason is less than half the size of this comet and is
| considered abnormally large.
|
| [0] https://en.wikipedia.org/wiki/Comet_Humason
| spenczar5 wrote:
| For the HN crowd, it may be especially interesting to note that
| this was pretty much a software discovery.
|
| The dataset here was DES, the Dark Energy Survey. It's a big
| dataset that has been around for a few years, and probably
| thousands of astronomers have worked with it. But its just a huge
| amount of data, covering a lot of the sky.
|
| Bernardinelli's _software_ discovered a blip in that big pile of
| data. He crunched through the dataset and got a weird answer for
| the size of the solar system (basically - its a bit more
| complicated). Almost everyone, when they get something like that,
| tweaks the parameters of their analysis code: "I must have the
| threshold for object detection set too low." The real discovery
| comes from trusting the software and pursuing the question.
|
| This is a lot like software developers and their persistence.
| When your production service has a mysterious error in the logs,
| do you shrug and say "well, probably some transient network bug,
| it won't matter" or do you dig in to understand what's going on?
| Both approaches are reasonable, and it takes a balance of
| pragmatism and curiosity to be effective.
|
| But anyway - there is an increasing demand for applying rigorous
| software engineering techniques to astronomical datasets. A
| problem that we are facing in astronomy software today is that
| the datasets have gotten way too large for astronomers to just
| pull up images in DS9 and eyeball stuff to make sure it's right,
| so they need software that is much more trustworthy and bug-free
| than before.
|
| ---
|
| Edit to add: DES data is completely public access:
| https://www.darkenergysurvey.org/the-des-project/data-access...
| AceJohnny2 wrote:
| I love this point, and I have to go on a tangent on this:
|
| > _This is a lot like software developers and their
| persistence. When your production service has a mysterious
| error in the logs, do you shrug and say "well, probably some
| transient network bug, it won't matter" or do you dig in to
| understand what's going on? Both approaches are reasonable, and
| it takes a balance of pragmatism and curiosity to be
| effective._
|
| I find that it really depends on how harried I am. Am I (or
| someone on my team) able to dedicate time to this issue, or do
| we have other higher priority concerns?
|
| _Every single time_ I can think of where we 've had a "that's
| weird", it was a bug in the software. But it would take days to
| weeks for someone find the root cause (these were 1 in 100,000
| race conditions), and we just can't afford to dedicate that
| amount of time to each.
|
| So we have to pick our battles.
| lifeisstillgood wrote:
| When the system is the Solar System, or the human nervous
| system, I say society has an ROI worth multiple PhDs to
| invest - but for an ad service that is likely to be
| completely replaced in a decade - yeah it's a lower ROI
|
| But this raises the interesting (to me) question - almost
| every enterprise I know operates at the "harried" level - no
| one is so well funded they can saunter around
|
| But science is basically saying "we trust you to find
| something worthwhile. Go saunter"
|
| Maybe it's all about trust
| jhgb wrote:
| > When your production service has a mysterious error in the
| logs
|
| ...such as a 75 cent accounting discrepancy? ;)
| ThomasBHickey wrote:
| https://en.wikipedia.org/wiki/The_Cuckoo%27s_Egg_(book)
| jonahbenton wrote:
| Please say more. How does a software engineer with a data
| engineering background and interest in astronomical phenomena
| learn about/start contributing to this area?
| ampdepolymerase wrote:
| Most of such jobs pay peanuts (relatively speaking). Academia
| is something to consider as a hobby or after you retire.
| gammarator wrote:
| There is huge need for these skills in astronomy, but it can
| be tricky to find the right way to plug in.
|
| There is plenty of opportunity to contribute to open-source
| ---astropy is one of the most active projects, as a starting
| point.
|
| Deeper (volunteer) engagement probably requires finding a
| willing scientist to plug you in to a project. That can be
| tricky get going and to make mutually beneficial.
|
| There are full time research software engineer positions--
| these will pay less than industry, of course; for some folks
| the subject matter and environment make that trade
| worthwhile.
| brainwipe wrote:
| It's nice to have a comet named after you right up to the point
| when you realise it's en-route to Earth _! Mum and Dad were so
| proud...
|
| (_It's not)
| [deleted]
| notjustanymike wrote:
| One of the most exciting phrases uttered in Science isn't
| "Eureka!" but rather
|
| > "'This is weird -- what is this thing?'"
| rubenv wrote:
| Or: "How on earth could this code possibly work?"
| maverwa wrote:
| Thats the worst. The moment the problem flips from "whats
| wrong with this code?" to "Why does this even work?" and you
| learn how little you really know.
| protomyth wrote:
| John Ringo's _Live Free or Die_ starts with a nice explanation:
|
| _"It is said that in science the greatest changes come about
| when some researcher says "Hmmm. That's odd." The same can be
| said for relationships: "That's not my shade of lipstick . . ."
| --warfare: "That's an odd dust cloud . . ." Etc."_
| lapetitejort wrote:
| Unfortunately the principle does not hold up for software
| development. If people made discoveries every time they
| encountered some strange code, we'd have The Matrix running
| in no time.
| lifeisstillgood wrote:
| Perhaps we did ;-)
| hodgesrm wrote:
| --Fires in California: "That's a strange cloud..."
|
| Not making it up, this is exactly what we thought when the
| Oakland Hills fire of 1991 started. Our confusion was short-
| lived, I'm sad to say.
| CalChris wrote:
| Same thing for me. I was having brunch in Pacifica and when
| I headed back to San Francisco, I saw this weird cloud
| where it shouldn't be. It was an otherwise clear day and it
| was blowing backwards, towards the ocean, due to whatever
| the Northern California equivalent of a Santa Ana wind is.
| QuercusMax wrote:
| I think they're the Diablo winds in the Bay area?
| phkahler wrote:
| Today at work: "What's that smell?" after a quick look
| around "There's a bit of smoke coming off that
| transformer." Bigger problem averted.
| [deleted]
| Macha wrote:
| > ("It's not like this is the Pedro and Gary show at all,"
| Bernstein said. "In fact, we wanted the comet to be called Comet
| DES, but apparently that's against the rules.")
|
| Des is a name here (short for Desmond). Hacky alternate reality
| solution: Hire a guy named Des to have the comet "officially"
| named after.
| [deleted]
| sigmaprimus wrote:
| Oh great another comet...Neo-wise was the harbinger for COVID-19.
| I wonder what kind of doom this thing is bringing us for 2031?
| laylomo2 wrote:
| I enjoyed the writing of this article.
| ncmncm wrote:
| What I would like to know is whether there is any indication from
| the DES whether there is, in fact, any Dark Energy activity at
| all.
|
| Last I heard, DE was discovered to be, probably, a product of a
| pervasive miscalibration. I have not heard of any retraction or
| rebuttal. The recognition coincides with evaporation of galactic
| rotation curves as an indication of Dark Matter, also not, to my
| knowledge, rebutted. Cosmology is not unique in systematically
| ignoring evidence against the existence of its favorite phenomena
| -- Nessie and Bigfoot fans, either -- but its claims are the
| biggest.
| rnd420_69 wrote:
| Huh? There is zero argument about the existence of dark energy
| in the scientific community. It's existence is obvious because
| you can actively see galaxies accelerating, on average, away
| from each other in all kinds of datasets observing the sky.
|
| The questions are all about what actually causes it / the
| mechanism behind it, and details about its workings.
| [deleted]
| T-A wrote:
| > There is zero argument about the existence of dark energy
| in the scientific community.
|
| https://www.wired.com/story/does-dark-energy-really-exist-
| co...
|
| > It's existence is obvious because you can actively see
| galaxies accelerating, on average, away from each other in
| all kinds of datasets observing the sky.
|
| No. Acceleration is inferred by fitting observed values of
| other quantities to the Friedmann equations.
|
| https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existe.
| ..
|
| https://en.wikipedia.org/wiki/Friedmann_equations
| ncmncm wrote:
| I gather the precise validity of the Friedman equations
| depends on the universe being "homogeneous and isotropic",
| on a large-enough scale, yet not so large a scale as to
| render the terms meaningless.
|
| But we keep finding the universe not to be uniform, even on
| a 100M parsec scale. A much larger scale would be
| uncomfortably close to the perceived size of the universe
| itself, flirting with that meaninglessness. So, it seems
| hard to know how the results are affected by such non-
| uniformity, or how much correction is needed.
| ceejayoz wrote:
| https://en.wikipedia.org/wiki/Dark_energy doesn't contain the
| word "calibration" at all, so perhaps you could cite a source?
| Jiro wrote:
| "Megacomet" is exaggeration. Chiron, which is anomalous in its
| own way, is of similar size.
| codezero wrote:
| I studied comets, and published some original research on comet
| tail interaction with the solar wind, not that my opinion
| matters much, but in my experience for what most researchers
| classify comets, this is absolutely a megacomet. It's more than
| twice as large as the one I kept in my mind from a decade ago
| that I considered one of the larger comets and Humason [0] was
| only about 40km in diameter.
|
| Yes, cold bodies that have the properties of a comet may have
| lived the life of a comet at some point, or will again in the
| future, but currently something that shares a common center of
| mass with another object in a pretty stable orbit is not really
| going to get the full comet red carpet at the comet awards :)
|
| [0] https://en.wikipedia.org/wiki/Comet_Humason
| himinlomax wrote:
| Chiron is not a comet.
| nnutter wrote:
| Wikipedia more-or-less disagrees with you.
| bserge wrote:
| I like how it's "Wikipedia" that disagrees. Not the
| rando(s) who wrote or edited the article.
| TeMPOraL wrote:
| Well, it's the randos who wrote or edited the article,
| and the greater number of randos who read it afterwards
| and _didn 't_ edit it.
| hunterb123 wrote:
| Chiron is a planet.
|
| Chiron is a comet.
|
| "Wikipedia" agrees with both of those statements.
|
| Since it cannot be both, "Wikipedia" also agrees with the
| statements that Chiron is not a comet and is not a planet.
|
| tldr: we don't know, it could be either
| adolph wrote:
| _2060 Chiron /'kaI@ran/ is a small Solar System body in
| the outer Solar System, orbiting the Sun between Saturn
| and Uranus. Discovered in 1977 by Charles Kowal, it was
| the first-identified member of a new class of objects now
| known as centaurs--bodies orbiting between the asteroid
| belt and the Kuiper belt._
|
| https://en.wikipedia.org/wiki/2060_Chiron
|
| _In Greek mythology, Chiron ( /'kaIr@n/ KY-r@n; also
| Cheiron or Kheiron; Ancient Greek: Kheiron means 'hand')
| was held to be the superlative centaur amongst his
| brethren since he was called the "wisest and justest of
| all the centaurs"._
|
| https://en.wikipedia.org/wiki/Chiron
|
| _Chiron - A centaur with a white stallion body[9] and a
| son of Kronos. He is the mentor of Percy Jackson and the
| activities director at Camp Half-Blood. In The Lightning
| Thief, he first appears, disguised as a Latin teacher at
| Percy 's school. He uses an enchanted wheelchair to
| conceal his horse half.[7] Chiron is played by Pierce
| Brosnan in the first film and by Anthony Head in the
| second film. In the musical, he is portrayed by Jonathan
| Raviv._
|
| https://en.wikipedia.org/wiki/List_of_characters_in_mytho
| log...
| codezero wrote:
| Also, it's fair to say systems based on classification
| based on subjective criteria will always have grey area,
| so any absolute statement about them will be difficult to
| defend :)
| barbazoo wrote:
| Wow I had to disable ublock origin and pi-hole to make that page
| load, wth.
| Macha wrote:
| Weird, works for me with UBO + Firefox ETP + Privacy Badger
| astatine wrote:
| Serendipity, or luck if you prefer, seems to play such a big role
| in these things.
| j_walter wrote:
| I would say good timing versus luck. They didn't just happen
| upon it staring through a telescope at the right time...their
| research was setup to find objects similar to a comet but
| slightly further away from the sun than where they found it.
| NoGravitas wrote:
| Is anyone else disappointed to learn that it won't be impacting
| the Earth?
| cheese_van wrote:
| Most working astronomers doing original work (often looking for
| "something weird) do their own coding. That always impresses me.
| I have hard enough time with code but these guys not only code
| but do hard science. "Damn" I say under my breath, "that rules".
| MattGaiser wrote:
| Lots of scientists in general. I help a neuroscientist friend
| with his from time to time and was surprised at how much custom
| code is running in his lab.
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