You can't see them simultaneously. But, especially from the Northern Hemisphere, March 2018 is a great month for catching all 5 bright planets either after sunset, or before dawn.
Expand to full size to see this video from ESA’s Mars Express spacecraft, which caught a close-up view of the little Mars moon Phobos, moving in front of distant Saturn.
They used a radio telescope to peer back to a time only 180 million years after Big Bang - when the 1st stars were turning on - to observe the earliest-yet signals of hydrogen gas.