There's a good chance that asteroid strikes have blown off matter from Earth to seed other planets for life, according to new research.

Scientists have revealed the results of the biggest simulation of Earth ejecta ever undertaken, suggesting that some of Earth's hardier life-forms may have travelled as far as Jupiter and beyond, sometimes even out of our Solar System. They say that this increases the likelihood that the ejecta may have landed on habitable planets.

The team, led by Mauricio Reyes-Ruiz from the National Autonomous University of Mexico, created a computer model to simulate the ejection of over 10.000 particles from Earth, and followed their movements for 30.000 years - the length of time that astrobiologists believe Earth's hardiest lifeforms might survive in space.

The report appears on the physics website arXiv and has been submitted to the journal Icarus. "The collision probability is greater than previously reported," said Reyes-Ruiz.

Ever since the discovery on Earth of rocks ejected from the Moon and Mars by asteroid strikes, scientists have considered the chance that matter from Earth could be spread around the galaxy.

Prior research has shown how biological matter could be carried on these particles, and could possibly seed life elsewhere in the Solar System if it collided with a suitable target.

Testing whether the matter would actually reach such targets was done by simulating how far Earth ejecta can travel after being blasted off our planet. While it was considered fairly likely that some would end up on the Moon or Venus, the chances of any landing on Mars was assumed to be low because it would have to overcome the Earth's and the Sun's gravity.

But this new study overturns that assumption, showing that the number of particles that would collide with Mars is far greater than previously thought.

And more surprisingly, at higher ejection speeds, the simulated particles were much more likely to end up hitting Jupiter than Mars. Some would even go beyond Jupiter and out of our Solar System.

The team used a computer program to model 10.242 particles ejected from Earth by a massive impact. This is more than three times the number of particles previously studied, and they tested the particles at five different impact speeds, increasing the exit velocity of the matter each time.

As they increased the velocity of the particles, the chances of them hitting the Moon or Venus decreased, and more where thrown towards Jupiter. Of the 10,242 tested, 691 particles 'escaped' out of the Solar System entirely, and six landed on Jupiter itself. The chance of hitting Mars was highest at middling velocities, because the matter would have enough speed but wouldn't fly straight past Mars's low gravitational field.

Combined with the work of astrobiologists, who estimate 30.000 years as the maximum amount of time life from Earth could survive in space, this study shows that it is at least possible for life to be carried to a new, hospitable home.

Source: Icaros