How can I add Wikidata properties of item a on the Wikipedia page of item b?

Question

How would I get the eccentricity (Property:P1096) of Venus (Q313) in the article en:Mars?

I have figured out that I have to write {{#property:P1096}} if I want to get a property of the page on that page, but another pages property seems not to work.

What I've tried

None of these worked:

• {{#property:P1096|of=Q313}} <- includes the property of the current page
• {{#property:P1096|id=Q313}} <- includes the property of the current page
• {{Q313#property:P1096}} <- messes up

Answer 1

According to v0.4 of the Wikidata inclusion syntax, this feature has not been implemented yet. The progress of this feature is available in the Wikimedia bug tracking system.

Answer 2

And just to add to the others, now it is available on English Wikipedia, and you would use it like this: {{#property:P1096|from=Q313}}

Answer 3

To add to Patrick's answer, "arbitrary access" to Wikidata items from other Wikipedia pages is now available:

https://www.wikidata.org/wiki/Wikidata:Arbitrary_access

It's currently (14 May 2015) live only on French Wikisource and Dutch Wikipedia; next week it will go live on Farsi Wikipedia, English Wikivoyage, and Hebrew Wikipedia; and if all goes well will be rolled out on all projects in June.