Sending Earth-Life to Phobos?

In the near future, the Russian space agency and the Planetary Society will be sending samples of life to the Martian moon, Phobos. The mission, known as Phobos-Grunt, aims to send several different types of Earth-life to the barren moon of Mars. The Planetary Society will be sending 10 life forms in its cargo. These include tardigrades (or water bears), various plant seeds, and bacteria cultures. The Russians are sending more complex life, also, including some crustaceans, mosquitoes, and fungi. The Russians have already tested whether a mosquito can survive in space (they can).

The purpose behind this mission is to determine the effects of long-term space travel on biological systems. Lessons learned here may affect future plans for human flights to Mars or beyond. The Phobos-Grunt mission, isn't a one-way suicide mission, however. The samples will be returned to Earth for observation and testing. Also, this mission is intended to be an example of "reverse panspermia", if you will. By determining whether life can survive long-term exposure to radiation and temperature variations, this mission can give us insights into the possibility of panspermia (life originating on Earth via microbes arriving on meteorites).

This seems to fly in the face of typical spaceflight practices, however. Typically, a spacecraft not carrying humans is sanitized of all life forms before launch, to prevent an accidental spread of Earth life to other planets. Now, we're purposely sending our life forms to, in this case, a nearby planet's moon. While there wouldn't be any life to disturb on this airless moon, what are the ethics of sending Earth life to space? Can we ethically plant life on other planets? If so, what checks do we need to execute to ensure we don't destroy something that was already there? Needless to say, since Phobos has no atmosphere, the chances of life ever procreating there are about zero. As such, its not a really big deal for us to even leave life there. If, however, these organisms return from their trip, it might be strong evidence to the possibility of panspermia.

What do you think?