Utopia 4-7 is the seventh level of Utopia.
It's very hard to get the perfect shot to kill all pigs, but to shots can still 3 stars.
For Utopia 4-7, send the first Blue bird over the northern tower and into the big red bumper on the far side of the planet. Split late and, with a bit of luck, you can detonate a couple of the TNT scattered around the planet. If any structures still remain, use another Blue bird to blast its TNT as well.