Re: Simbad data in Google Sky

From: Alberto Conti <aconti-at-stsci.edu>
Date: Thu, 6 Sep 2007 09:37:11 -0400

On Sep 6, 2007, at 8:48 AM, Robert Hanisch wrote:

> It is cool, yes, but I want to also express some caution.
>

and I agree.

> When you display the SIMBAD objects in GoogleSky there is a
> potential for
> great confusion. For example, there is no indication of the
> positional
> uncertainty.

true, but there is also no reason why it cannot be added. Remember this is just GoogleSky 1.0 and it needs improvements. Symbols are also very confusing and more so since they related to terrestrial features. But again, this can also be easily changed, but providing a standard pushpin library for astronomical objects that have been classified. Perhaps some in the VO could actually propose that.

> All you see are symbols and these more often that not do not
> correspond to any object visible in the DSS or SDSS image. Of
> course, many
> of the objects are from different bandpasses -- x-ray sources or
> molecular
> clouds or whatever -- and may have no obvious optical counterparts
> anyway.
>

Yes this is indeed a problem, but as time goes by tools will become available for people to add large collections to this client. Google will soon release tools that will allow a wcs2kml translation directly from fits with a "regionation" option that will allow a image pyramid to be build from fits and loaded as jpegs in GoogleSky. This will also be applicable to catalogs.

> This is no different from Aladin or any of the other visualization
> tools we
> have for VO users, save for the fact that the VO tools in the
> astronomy
> community are designed for astronomy-aware users who typically ask
> to see
> catalogs of interest as motivated by astrophysical research questions.
> GoogleSky opens up these rich but intrinsically complex datasets to a
> potentially huge community, and there is a potential for significant
> confusion and misunderstanding.

well, if the eyes of those that look at this client are those of astronomers, then I think the potential if highly reduced for any confusion. Particularly if once is able to link to astronomical datasets in the VO.

> (Note also that the geometric projection
> that GoogleSky uses is worthless at the poles.)
indeed, but this was a design compromise that had to be made. We will continue to push Google, and the astronomers that work at Google, to correct this and other problems. Again this is GoogleSky 1.0 and can and hopefully will be improved ALSO with the input of astronomers interested.

> I am not suggesting that we
> should not provide this kind of access, but we need to think a bit
> more
> carefully about how the capabilities of GoogleSky plus KML-based
> catalogs
> will help people to understand astronomy.

I think that the time to be careful has passed. GoogleSky, for better of worse is out there. One needs to decide if this type of interface can be used by astronomer and the VO or not. Does this provide a new platform to non-astronomers to view astronomical data hosted on VO- compliant services? I think so, and VO should consider using this tool (and all the others that will come, do I hear WWT?) to do some public relations for VO.
Does GoogleSky also provide a way for professional astronomer to enrich their work? I don't think this is the case at the moment and GoogleSky does not compare to Aladin in its present form, for many many reasons. I believe this step will take much longer, but I was proven wrong many times, even with what's possible and what's not in GoogleSky, so I am willing to wait before I make up my mind on this one till I have more data.

Ciao,
Alberto

>
> Perhaps we can have a discussion on this topic at the Interop in
> Cambridge.
>
> Bob
>
> On 9/5/07 7:53 PM, "Chenzhou CUI" <ccz-at-bao.ac.cn> wrote:
>
>> Cool!
>>
>> The astronomy applications for Google Sky are increasing rapidly. It
>> seems that Google Sky becomes a potential competitor of VO
>> portals, i.e.
>> Aladin.
>>
>> Cheers,
>>
>>
>> Thomas Boch wrote:
>>> Dear Apps members,
>>>
>>> We have worked the last few days on providing Simbad data in
>>> Google Sky.
>>> The KML file is available here :
>>> http://cdsweb.u-strasbg.fr/googlesky-pages/simbad.kml
>>>
>>> Once loaded in Sky, it will retrieve Simbad objects and display them
>>> with various icons according to the object type. The query is
>>> actually
>>> performed if and only if the span of the current view is smaller
>>> than
>>> 0.5 deg.
>>> The attached snapshot gives you an overview of what it looks like.
>>>
>>> Your comments and feedback are very welcome.
>>>
>>> Cheers,
>>>
>>> Thomas, for the CDS team
>>>
>

Dr Alberto Conti
Community Missions Office Development Manager Space Telescope Science Institute
contact | tel: 410-338-4534 | aim: wscience Received on 2007-09-06Z15:37:34