Lethal damage and effects that say "destroy" won't cause Darksteel Juggernaut to be put into the graveyard. However, it can be put into the graveyard for a number of other reasons. The most likely reasons are if its toughness is 0 or less or it's sacrificed.
The first ability works in all zones.
Since Darksteel Juggernaut is itself an artifact, its power and toughness will always be at least 1 while it's on the battlefield (unless a spell or ability somehow changes its card type).
Last observed on Scryfall 2 months ago at $1.38. Over the trailing 90 days the price moved between $0.02 and $1.40 across 45 observations. Cross-checked across TCGplayer, eBay sold, Cardmarket EU, and Star City.
This printing is one of 3 catalogued treatments from SOM — the lineup includes Foil and Nonfoil alongside the standard finish. Across our catalog the Rarix library tracks every variant in the same family so collectors can compare price, scarcity and demand inside a single lineage.
Card #150 of *Scars of Mirrodin*, the set that shipped alongside the October 2010 Scars of Mirrodin release.
Card type: Artifact Creature — Juggernaut, printed at rare. Rares occupy the bottom-of-pack rare slot in standard boosters. Mana cost: {5} (5 converted). Keyword abilities: Indestructible.
Legal in Modern, Legacy, Vintage, and Commander.
EDHrec ranks this card #4,716 in Commander, putting it in the niche-pick tier of the format's playable pool.
Illustrated by Randis Albion. Rarix catalogs 22 other cards credited to this artist.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Randis Albion
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
If, during your declare attackers step, Darksteel Juggernaut is tapped, is affected by a spell or ability that says it can't attack, or is affected by "summoning sickness," then it doesn't attack. If there's a cost associated with having Darksteel Juggernaut attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either.
