The UK parliamentary rulebook Erskine May notes: "When Parliament stands prorogued to a certain day, the Queen may issue a proclamation, giving notice of her intention that Parliament shall meet for the dispatch of business on any day after the date of the proclamation; and Parliament then stands prorogued to that day, notwithstanding the previous prorogation".
"The lower court had said the actions of the executive were "non-justiciable" - meaning they were not to be examined by judges".
Union leaders called on Johnson to recall parliament or face further protest and court proceedings.
Tim Roache, the general secretary of the GMB, said: "Shutting down parliament for your own ends at a time of national crisis, when people's jobs and livelihoods are on the line, beggars belief".
What will happen next, and whether MPs head back to Westminster, will be fought out in both the political and legal arenas.
Len McClusky, the leader of Unite, one of Britain's biggest trade unions, and one which gives financial support to Labour, has advised the United Kingdom prime minister not to visit Scotland as he may "face a citizen's arrest".
The court is likely to make a ruling later in the week. "He's broken the law, is not fit to hold office and along with this disgraceful government must be held to account", he said.
Parliament last week passed a law requiring Johnson to seek an extension to the October 31 deadline for Britain's exit, essentially taking no-deal off the table. As of Monday, that is now law.
"It means that if the prime minister fails to get a Brexit deal by 19 October - as looks increasingly inevitable - or a mandate for no deal - which is equally unlikely - he will have to seek and accept an extension to article 50".
"The legal advice is clear that the prime minister must abide by this".
China lands probe on dark side of the moon
Its plans include establishing a permanent manned space station, a manned lunar landing, and eventually probes to Mars. The Chinese Jade Rabbit 2 rover is making tracks on the soft, snowlike surface of the far side of the moon.