Disadvantages of In-Office Whitening. 1  In-office bleaching is more expensive than take-home alternatives. 2  Its cost, on average, is $650, compared to $400 for take-home trays and under $100 for over-the-counter bleaching trays or whitening strips.
Planetary protection is a guiding principle in the design of an interplanetary mission, aiming to prevent biological contamination of both the target celestial body and the Earth in the case of sample-return missions.
Preparing for the Future. Planetary protection: preventing microbes hitchhiking to space. While astronauts might dream of discovering unknown life one day in their future career, ESAâs Planetary Protection Officer oversees activities that achieve it on a regular basis.