Polaris 50th Anniversary Hashtag: Ideas?

Almost a week ago, I asked if there should be a Twitter hashtag made specifically for Polaris’ 50th anniversary. Eight out of ten people said yes.

Next question becomes, what hashtag is best?

My initial thought was #Polaris50. It has a handful of uses, but not enough to be a “hijacking” of a hashtag, and most recent use was January 21. I also think it’s short enough to get use. But, you’d also have to know what the hashtag means already.

@aka-vinny suggested 

#50YearsofPolaris and #Polaris50thAnniversary on the Tumblr post I made about Twitter hashtags. They have no uses yet, and they’re clearer on the purpose of the hashtag, but I feel like they might be too long.

Anyone have any thoughts about hashtags? These hashtags? Suggestions for something different?