Launch | Potential collision of nanocraft with planet

Breakthrough Starshot has no intention of colliding any nanocraft with any object in space. Even though an accidental collision between a nanocraft and another object is a remote possibility happens, the resulting effects must still to be examined.

A gram-scale nanocraft traveling at approximately 20% of the speed of light carries with it a kinetic energy equivalent to about 0.5 kilotons of TNT. If the nanocraft were to intercept an Earth-like exoplanet with a thick atmosphere, it would burn up in the atmosphere.

If it were to collide with a body resembling the Earth’s moon, it would create a small crater (on the order of 10m). NASA and others have collected significant amounts of data on the historic rates of asteroid collisions with the Earth, and determined that such collisions are frequent. Asteroids that deposit on the order of 1 kiloton of energy collide with the Earth about once a month.

Nanocraft-scale impact poses a very small chance of causing harm to any planet.

Comments (16)

  1. Melih Çalıkoğlu:

    I would suggest for a deliberative collision with a planet. Such an entry probe would enable us to analyze the atmosphere of exoplanets, and may be take a few picture of the surface features up close. If the problems with the speed would be solved by some kind of gravitational breaking procedure or may be using the light of the host star to slow down the craft that would lead to a possible successfull probing mission.

  2. John McLean:

    At 0.2c, the craft would have no time to analyse the atmosphere before being vapourised. There is no feasible mechanism so far proposed to allow any meaningful amount of braking - bear in mind we are talking about using a 100 GW laser array to accelerate, which is several orders of magnitude greater than solar flux on earth. A flyby within 1AU would allow a spectroscopic analysis of the atmosphere and the opportunity for some photography. You'd hope to be able to identify moons orbiting an exoplanet, surface temperature, presence and composition of atmosphere, maybe evidence of geological activity. A lot of information can be gleaned without smashing into things.

  3. Nemo in Nihilum:

    Well, since it's my first post here, something else beforehand:

    Hello everybody!
    Nice to read you all.

    On the topic:
    As Mr. Hawking put it, "the probability of finding intelligent alien life is very small,... probably".
    Moreover the probability of finding some kind of life at all, is not neglectable.
    Hence, I would not collide any spacecraft with a foreign celestial body on purpose, as long as we are not sure its uninhabited (or not harmful, which we cannot be sure of, without thoroughly knowing a potential ecosystem).
    Imagine a low gravity planet with a low density atmosphere and some big floating creatures.
    Even if not intelligent, I would not want to kill anything by accident.

  4. Karen Pease:

    John is correct. It's also worth mentioning that data transmission rates are going to be *tiny*. It's not like you can rapidly send out some last minute pre-collision photo.

  5. Luka Marinovic:

    As Pete Worden suggestion, I'm posting my suggestion for a Light beam here:

    1. You don't need a power for laser, 'cause we already have it! It's the Sun!
    Just check the movie "Diamonds are forever":
    In essence, a big enough Sun collector that can focus a beam can be used as a laser. Just don't turn it towards the Earth this time!
    No - just joking, you can use it for:
    a) moving asteroids from their trajectory, preferably farther from Earth! (plan has been made with NASA, so you can also collaborate on that research to make a powerful enough laser). Maybe NASA would like to fund such lasers for a protection of the Earth?!
    b) power up the probe to Alpha centauri
    You certainly wont get out of power soon, by using electrical power to power up lasers...nor will you have problem with power delivery! Just design the Sun-collector to be Solar storm proof...

    2. If you manage to design such a laser, than a solar sail will have to absorb the wavelength of the Sun from the laser. It would also have the additional power from the Sun (at least up to Jupiter orbit), depending on the scale of the Solar sail. But, as the Alpha centauri 1 is similar in wavelength of our Sun, the Solar sail can be used as a:
    a) Solar parachute into the Alpha centauri system - maybe not to slow down the probe much to enter the system (but why not, maybe even that trajectory can be obtained?!), but at least to slow it down to get more time for observation & more time to get pictures from another star system.
    b) Can also be used to steer the probe around some objects in inner Alpha centauri system. Because it would be bad if a probe comes to Alpha centauri & crashes on planet similar to Uranus or Neptune...

    Hope that the ideas interest you...

  6. Nick Buer:

    On the remote possibility that there is an outpost of technologically advanced intelligence at Alpha Centauri, perhaps it would be best to attempt to send them a friendly electromagnetic message at least 10 years or so before we launch nanoprobes that will violate their personal space.

  7. marco palma:

    nick buer good idea ! maby sending a music its a solution for comunicate whit ac in good vibrations


    An object traveling at 0.2c hitting an atmosphere would radiate high energy radiation such as x-rays and UV but any thick atmosphere would likely filter out a lot except in a very narrow cone some of which would hit the ground. If one of these sails was used to hit an atmosphere it could tell us alot about the atmosphere which could be picked up by following probes.

  9. Luis C:

    If by the time we send these nano crafts we have the technology to include nano or microbots that could survive the high energy impact of colliding with a planet or planetoid then we could deliberately crash and have these probes build a communication array from local resources. This would present the opportunity of remotely building a deceleration laser array or other tools that can help us study the vicinity.

  10. Breakthrough Initiatives :

    Jun 13, 2016 14:35 Posted on: Centauri Dreams
    "An object traveling at 0.2c hitting an atmosphere would radiate high energy radiation such as x-rays and UV but any thick atmosphere would likely filter out a lot except in a very narrow cone some of which would hit the ground. If one of these sails was used to hit an atmosphere it could tell us alot about the atmosphere which could be picked up by following probes."

    The nanosat is in a different regime than interplanetary debris with similar kinetic energy. While collisions with interplanetary debris happen at velocities of less than about 100km/s, the nanosat moves at 60,000km/s. Nanosat collisions would indeed produce some short wavelength EM radiation not present in regular interplanetary collisions. Detecting the short duration low power flux from this radiation at 1-2 AU is however much more demanding than imaging the planet and would additionally require conveniently located probes. Note that the on target time for the nanoprobes at 0.2 c velocity is about 1,000 sec, assuming a 2AU ‘usable’ distance.

    – Prof. Sasha Buchman, Breakthrough Initiatives

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