If you see a space link in a message, or a space in search results, hover over to see the space details.

When you hover over the space contact card, you can see the space name, the team it belongs to, the number of members, and when it was last active.

When you click on the name of the team, you can easily see the unjoined spaces that are in that team. This is really helpful as you can see the latest active spaces, and those spaces which haven't been active in a while, before joining them.

When you're sure it's the space you're interested in, you can send a Message, or copy the space link from the space contact card.