If the bacteria floated up to LEO (which is very possible) the impact was likely in the meters/second range because it would have had to match the orbit closely enough. Because bacteria are so small (and the filaments they use to support the cell membrane is so strong) it would take an extreme impact to "splatter" them. Remember also that archaeic bacteria (as well as simple multicellular organisms) live on the bottom of oceans like the Mariana Trench where the pressure is over 1,000 atmospheres (enough to turn you into a miniature hockey puck).
The article is unclear whether these organisms are alive or not.
> Results of the scope of scientific experiments which had been conducted for a quite long time were summed up in the previous year, confirming that some organisms can live on the surface of the International Space Station (ISS) for years amid factors of a space flight, such as zero gravity, temperature conditions and hard cosmic radiation. Several surveys proved that these organisms can even develop.
Panspermia is a theory for a reason. As an explanation for life on Earth itself it has a challenge ahead of it, but due to the small amounts of life that Earth is known to be flinging about it's a known fact that Earth life has landed on the other planets. (Or at least their corpses, but it seems reasonably likely that some of it would survive the trip in some form of stasis or spore, given how resilient we know microscopic life can be.)
If life is ever found on Mars, the next question to be asked after identification is, "is it related to Earth life?" Which we'd check by checking certain of the parameters of life on Earth that do not seem to be "forced" by physics, but are universal on Earth (how DNA codes for proteins, for instance). If they all matched up, it would strongly suggest one single common origin... though that origin could conceivably be on Mars.
Interestingly, this also means that if the Solar System is still otherwise sterile despite the arrival of Earth life, that has interesting implications of its own.
