1 To be safe, USDA recommends that all pressure canners must be vented 10 minutes before they are pressurized. 2  To vent a canner, leave the vent pipe (steam vent) uncovered (or manually open the petcock on some older models) after you fill the canner and lock the canner lid in place.
There would be no place to land, and the ship would get crushed under Neptune's massive gravity, or ripped apart by its weather. To get there, we would have to build a space ship that can travel extremely fast. Then it would have to orbit Neptune or be incredibly durable to get inside of the planet. It would also need a large supply of O2, food and water.
Science Data Access. Voyager 2's view of Neptune, 57,000,000 kilometers (35 million miles) away (Click on the image for a larger view) In the summer of 1989, NASA's Voyager 2 became the first spacecraft to observe the planet Neptune, its final planetary target.