Cosmic visitor to wizzz Saturday/Sunday
Folks here might have heard that a small "house sized" minor planet will be passing within ~40,000 km of Earth a few minutes past noon MDT on Sunday. That's only about 1/10th the distance to the Moon. Obviously we wont be able to see it at noon. However, we in Utah do have a chance of spotting it on approach late Saturday night and early Sunday morning. Happily there's a star party Saturday night at SPOC so the Grim should be available and using that we just *might* be able to see it. Here are the data calculated for SPOC by the Minor Planet Center: Date UT R.A. (J2000) Decl. Delta V Object Sun h m s Azi. Alt. Alt. 2014 09 07 040000 22 33 32.8 -19 45 13 0.0034 15.1 316 +17 -24 2014 09 07 050000 22 34 11.3 -20 06 30 0.0032 15.0 330 +23 -32 2014 09 07 060000 22 34 50.9 -20 30 34 0.0029 14.8 344 +28 -39 2014 09 07 070000 22 35 34.7 -20 58 02 0.0027 14.6 000 +29 -43 2014 09 07 080000 22 36 27.3 -21 29 46 0.0024 14.5 016 +27 -43 2014 09 07 090000 22 37 35.6 -22 07 09 0.0022 14.2 030 +22 -39 2014 09 07 100000 22 39 09.3 -22 52 12 0.0020 14.0 042 +14 -32 BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE). See t'all tonight (Friday) at the Brickyard Harmons star party and tomorrow night at SPOC. patrick p.s. I think SLAS is still looking for someone to stand for next year's president. Any takers? To qualify you have to have been a member on 1 September.
It's for a very good reason. Astronomers and surveyors who actually do the trigonometry that converts RA/DEC coordinates to ALT/AZ have found that pointing zero to the south makes for a much easier math conversion. So the South as zero has been a convention for these "hard core" science types for a very long time. Another example is Seiichi Yoshida's excellent comet website. http://www.aerith.net/comet/weekly/current.html But of course this frightens some of the supposed gatekeepers of knowledge who insist on rigid conformity and relentless dumbing down. Like in our reoccurring debates about kilometers and kilograms it's just a colorful fact of life. It won't hurt you and if you ever try to "do the math" with celestial coordinates, you will quickly see why it's done that way. And you will be running with the big dogs. DT
BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE).
Schooled! ;-) On Fri, Sep 5, 2014 at 12:55 PM, daniel turner via Utah-Astronomy < utah-astronomy@mailman.xmission.com> wrote:
It's for a very good reason. Astronomers and surveyors who actually do the trigonometry that converts RA/DEC coordinates to ALT/AZ have found that pointing zero to the south makes for a much easier math conversion. So the South as zero has been a convention for these "hard core" science types for a very long time.
Another example is Seiichi Yoshida's excellent comet website.
http://www.aerith.net/comet/weekly/current.html
But of course this frightens some of the supposed gatekeepers of knowledge who insist on rigid conformity and relentless dumbing down. Like in our reoccurring debates about kilometers and kilograms
it's just a colorful fact of life. It won't hurt you and if you ever try to "do the math" with celestial coordinates, you will quickly see why it's done that way.
And you will be running with the big dogs.
DT
BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE).
I am not very smart... Is the answer because it is easier not having to deal with negative degrees? Subtracting relative degrees from 180 will never get you in to negative territory like subtracting from 0 will. By basing all relative calculations from 180 you can't ever get in to those situations (unless you start spinning in circles I suppose). It also means you don't have to be worried about 0 being equal to 360 except in the case when it is. How this makes trigonometry easier I have no clue. Trigonometry is already in the 'super-advanced' category in my opinion. I don't think there is a way to make it easier other than to avoid it entirely... Which I gather might be a problem if you want to launch a rocket or change orbits. -Ryan On Fri, September 5, 2014 13:13, Chuck Hards wrote:
Schooled!
;-)
On Fri, Sep 5, 2014 at 12:55 PM, daniel turner via Utah-Astronomy < utah-astronomy@mailman.xmission.com> wrote:
It's for a very good reason. Astronomers and surveyors who actually do the trigonometry that converts RA/DEC coordinates to ALT/AZ have found that pointing zero to the south makes for a much easier math conversion. So the South as zero has been a convention for these "hard core" science types for a very long time.
Another example is Seiichi Yoshida's excellent comet website.
http://www.aerith.net/comet/weekly/current.html
But of course this frightens some of the supposed gatekeepers of knowledge who insist on rigid conformity and relentless dumbing down. Like in our reoccurring debates about kilometers and kilograms
it's just a colorful fact of life. It won't hurt you and if you ever try to "do the math" with celestial coordinates, you will quickly see why it's done that way.
And you will be running with the big dogs.
DT
BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE).
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As for not being very smart…join the club. I’m to the point where I wear slip-on shoes because the ones you tie are too confusing. The wife checks each morning to make sure I have the correct shoe on the correct foot. She does come in handy. Dave On Sep 5, 2014, at 17:07, Ryan Simpkins <astro@ryansimpkins.com> wrote:
I am not very smart...
Is the answer because it is easier not having to deal with negative degrees? Subtracting relative degrees from 180 will never get you in to negative territory like subtracting from 0 will. By basing all relative calculations from 180 you can't ever get in to those situations (unless you start spinning in circles I suppose). It also means you don't have to be worried about 0 being equal to 360 except in the case when it is.
How this makes trigonometry easier I have no clue. Trigonometry is already in the 'super-advanced' category in my opinion. I don't think there is a way to make it easier other than to avoid it entirely... Which I gather might be a problem if you want to launch a rocket or change orbits.
-Ryan
On Fri, September 5, 2014 13:13, Chuck Hards wrote:
Schooled!
;-)
On Fri, Sep 5, 2014 at 12:55 PM, daniel turner via Utah-Astronomy < utah-astronomy@mailman.xmission.com> wrote:
It's for a very good reason. Astronomers and surveyors who actually do the trigonometry that converts RA/DEC coordinates to ALT/AZ have found that pointing zero to the south makes for a much easier math conversion. So the South as zero has been a convention for these "hard core" science types for a very long time.
Another example is Seiichi Yoshida's excellent comet website.
http://www.aerith.net/comet/weekly/current.html
But of course this frightens some of the supposed gatekeepers of knowledge who insist on rigid conformity and relentless dumbing down. Like in our reoccurring debates about kilometers and kilograms
it's just a colorful fact of life. It won't hurt you and if you ever try to "do the math" with celestial coordinates, you will quickly see why it's done that way.
And you will be running with the big dogs.
DT
BTW, for some reason (can anyone here explain?) MPC's idea of azimuth is 180 degrees off what I think most of us use. So subtract 180 for the azimuth numbers listed to get ones most of us are more used to (i.e. where is says 330, subtract 180 to get 150 in the SE).
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Sorry Ryan. I misstated what I was saying. One does not always subtract 180. In cases where the stated value is 180 or greater one would subtract 180. But for values less than 180 one adds 180. Part of my confusion comes from my aviation background. In flying 0 is always north, 90 is always east, 180 is always south and 270 is always west. Apparently in astronomy it's just the opposite with 0 is south, 90 is west, 180 is north and 270 is east. I did some poking around on the web and it appears all land, sea and air navigation have 0 as north and 180 as south. So it does seem a bit odd that astronomy would use the opposite. But with Daniel noting that surveyors also use the opposite apparently astronomy isn't the only one using it. So today I learned something new. :) patrick On 05 Sep 2014, at 17:07, Ryan Simpkins <astro@ryansimpkins.com> wrote:
I am not very smart...
Is the answer because it is easier not having to deal with negative degrees? Subtracting relative degrees from 180 will never get you in to negative territory like subtracting from 0 will. By basing all relative calculations from 180 you can't ever get in to those situations (unless you start spinning in circles I suppose). It also means you don't have to be worried about 0 being equal to 360 except in the case when it is.
How this makes trigonometry easier I have no clue. Trigonometry is already in the 'super-advanced' category in my opinion. I don't think there is a way to make it easier other than to avoid it entirely... Which I gather might be a problem if you want to launch a rocket or change orbits.
-Ryan
Ryann:
It's not so much a problem of how smart you are, what's needed is appreciating that different people do things differently.
I remember at a work site a plumber and an electrician were arguing after a switch was installed incorrectly by the plumber. It seems that when valves are open water flows, but when switches are open the current does not flow. The two fixed the problem at hand and agreed to disagree about who was right and who was wrong.
There is always a desire to pass a rule saying that every one does things the same way. The scope of the rule always falls short of achieving what was intended. Unless your a dictatorship like China which has only one time zone that spans a country wide enough for 5 of them.
The problem with minor planets like comets and asteroids is we have three hundred years of precise hand written documentation on paper. It would be nice to convert it all to a zero north standard so that it's more accessible to the general public, but no one has the budget or the inclination to do so. Surveyors and Astronomers agreed on a Gaza like truce with the land navigators and each has known about this little bump in the road for quite some time now.
We recently had a Physicist give a lecture about a telescope project. When questioned about the resolution of the instrument he gave his answer in micro-radians. There was a gasp of horror among the amateur astronomers who since the Phoenicians have used degrees,minutes and seconds. The Physicist wasn't being mean or showing off, It's just how he does all his record keeping.
It's part of the richness of human nature that people will always arrive at several ways of doing things, and it's OK.
DT
participants (5)
-
Chuck Hards -
daniel turner -
Dave Gary -
Ryan Simpkins -
Wiggins Patrick