Simulation shows how Earth may have seeded life on other planets

Aug 23, 2011 by Lisa Zyga weblog
Out of 10,242 simulated particles ejected from Earth, these figures show the number of particles that collide with nearby planets at three different ejection velocities, and the collision times. In the top panel, the values corresponding to collisions with Venus and the Moon are 10 times the actual values, which are too small to be plotted. Image credit: M. Reyes-Ruiz, et al.

(PhysOrg.com) -- When comets and asteroids impact Earth, we’re usually most concerned with how the impact events have affected life here. But scientists have pointed out that these impact events can eject pieces of Earth’s crust containing biological organisms into space, and if ejected at the right velocities from the right location on Earth, the ejected material could collide with another planet and seed life elsewhere in the Solar System. By using new simulations to analyze the dynamics of these ejected particles, and by tripling the number of particles compared with previous studies to improve the statistics, researchers have found that particles could not only reach Venus, the Moon, and Mars, but for the first time they show that particles from Earth could also reach Jupiter.

Mauricio Reyes-Ruiz at the Universidad Nacional Autonoma de Mexico and coauthors have posted their study on the collision probabilities of particles ejected from with other nearby planets at arXiv.org.

In addition to showing that particles ejected from Earth could reach Jupiter, their simulations also showed that the number of particles ejected from Earth that collide with Mars is two orders of magnitude greater than previous studies have found. The researchers explain that both results have astrobiological significance, especially due to the evidence for life-sustaining environments on early Mars and on Jupiter’s moons Europa and Ganymede.

In their simulations, the researchers analyzed 10,242 particles with a minimum ejection velocity of 11.2 km/s (which is required to escape Earth’s orbit). Different impact events throughout Earth’s history have ejected particles with a wide range of velocities, with the maximum determined by the speed of the impactor as it hits Earth. The researchers followed the simulated ejected particles for 30,000 years, which is the maximum estimated survival time for biological material in space.

Calculations have shown that an ejection velocity of 11.62 km/s is needed to reach Mars and 14.28 km/s to reach the orbit of Jupiter. While particles with ejection velocities of around 11.2 km/s have the highest chance of falling back to Earth, particles with ejection velocities of greater than 16.4 km/s typically get launched entirely out of the . Since these particles spend a very short amount of time in the inner Solar System, their collision probability with other planets is negligible.

The results of the simulation also showed that the probability of particles ejected from Earth colliding with other depends on the particular place on Earth from where the particles are ejected. Particles ejected from Earth’s leading face along its direction of motion, which are statistically more likely, have a higher probability of colliding with Mars and Jupiter, while particles ejected from the trailing face are more likely to impact Venus.

The researchers note that, overall, the probability of particles ejected from Earth colliding with another planet is very small. Further studies will be needed to investigate the velocity distribution of the ejected particles, along with simulations that use a greater number of ejected particles to estimate collision rates that have greater statistical significance.

Explore further: Google exec makes record skydive from edge of space

More information: M. Reyes-Ruiz, et al. "Dynamics of escaping Earth ejecta and their collision probability with different Solar System bodies." arXiv:1108.3375v1 [astro-ph.EP]

via: Physics ArXiv Blog

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TopherTO
2 / 5 (2) Aug 23, 2011
What about vice versa in terms of Ganymede and Europa? Could the probability of particles from an impact on their surface reach Earth as it presumably require much less energy to escape? Or does Jupiters proximity change things?

Either way, interesting article...
Nik_2213
not rated yet Aug 23, 2011
Jupiter's gravity does indeed change everything. eg It turned Comet Shoemaker-Levy 9's fragments' impacts into Earth-sized cloud-scars by accelerating the impactors...
omatumr
1.8 / 5 (4) Aug 23, 2011
As I recall, Fred Hoyle and his colleague at the University of Cardiff proposed that life on Earth came from other solar planets.

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo

Vendicar_Decarian
1 / 5 (2) Aug 24, 2011
Why ain't nobody looken wits dere tallscopes for lifes on da surface of Jupiter?

It's a neutron star ain it? Cause I sawen it on yooztoobz
antialias_physorg
1 / 5 (1) Aug 24, 2011
Jupiter's gravity does indeed change everything.

I remember a study which shows that Jupiter's overall effect on earthbound asteroids is close to zero (i.e. it doesn't suck up comets/asteroids. Mostly it just alters their paths. The net effect is that some get diverted away while others are diverted towards us...only the very small fraction that actually impacts Jupiter can be said to be 'sucked up')

So I could imagine that fragments of Ganymed have also a chance of making a slingshot maneouver around Jupiter and heading into deep space (or on a collision course with some other, hapless planet.)
89118a
4 / 5 (1) Aug 24, 2011
... biological organisms into space, and if ejected at the right velocities from the right location on Earth ...

I like to call this phenomena "Bird Theory" and not just 'cause I this it's for the birds. Ya see kids, when the great volcano erupted, the flying magma caught a bird who was flying overhead and took her all the way to Mars! And that's why there are only birds on Mars.

[sic] lol
_nigmatic10
1 / 5 (2) Aug 24, 2011
We can only speculate on where life came from previous to the creation of earth, but a fact does stand out from the entire list of theories. Life exists beyond our planet.
ravi_chathuranga
1 / 5 (1) Aug 24, 2011
This is What the lord Buddha preached 2600 years ago
I found this perfect match with Buddhism