A month whose 1st date comes on Monday and all the Sundays in that particular month follows the date pattern of 7 14 21 28 is known as Perfect Month. The name Perfect comes from the fact that it follows table of 7 which is the number of days in a week. Also, monday is considered as the first day of the week, hence coming of monday on the 1st date of a month is considered as Perfect Month.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.