SoylentNews is people
SoylentNews
from the sometimes-an-asteroid-is-just-an-asteroid dept.
The interstellar asteroid 'Oumuamua's likely movements have been tracked based on the relative positions of nearby stars. Observations of 'Oumuamua indicate that it has only been subjected to interstellar conditions (cosmic rays, gas, dust) for hundreds of millions of years rather than billions. There are likely to be around 46 million such interstellar objects entering the solar system every year, most of which are too far away to be seen with current telescopes, and are quickly ejected:
[My (Fabo Feng)] latest study gives us a glimpse of exactly where 'Oumuamua may have come from. Reconstructing the object's motion, my research suggests it probably came from the nearby "Pleiades moving group" of young stars, also known as the "Local Association". It was likely ejected from its home solar system and sent out to travel interstellar space.
Based on 'Oumuamua's trajectory, I simulated how it has probably travelled through the galaxy and compared this to the motions of nearby stars. I found the object passed 109 stars within a distance of 16 light years. It went by five of these stars from in the Local Association (a group of young stars likely to have formed together), at a very slow speed relative to their movement.
It's likely that when 'Oumuamua was first ejected into space, it was travelling at just enough speed to break away from the gravity of its planet or star of origin, rather than at a much faster speed that would require even more energy. This means we'd expect the object to move relatively slowly at the start of its interstellar journey, and so its slow encounters with these five stars suggests it was ejected from one of the group.
Pleiades star cluster. "Code and results" for the arXiv paper.
We should capture as many interstellar asteroids as possible and smash them together to create a new dwarf planet near the Earth.
Previously: Possible Interstellar Asteroid/Comet Enters Solar System
Interstellar Asteroid Named: Oumuamua
ESO Observations Show First Interstellar Asteroid is Like Nothing Seen Before
Breakthrough Listen to Observe Interstellar Asteroid 'Oumuamua for Radio Emissions (none were found)
(Score: 2) by edIII on Saturday January 06 2018, @09:16PM (4 children)
That seems awful high, or deep space is more populated with debris then we think.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 3, Insightful) by takyon on Saturday January 06 2018, @09:33PM (1 child)
6.0 × 10−3 au−3 = 166.66 per cubic astronomical unit.
46 million divided by that = ~276,011 cubic AU
The radius of a sphere with that volume would be 40.39 AU. Sounds pretty close, since Pluto has a semi-major axis of 39.48 AU.
We use a sphere and not a disk? Because the solar system actually looks something like this [wikipedia.org]. Plus, the objects could come from any direction.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Insightful) by takyon on Saturday January 06 2018, @09:49PM
Whoops.
166.66 cubic AU per object.
46 million objects * 166.6 cubic AU = 7,666,666,666.666 cubic AU
Radius = 1223.22 AU
So now the sphere encompasses Planet Nine and most ETNOs [wikipedia.org].
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2, Insightful) by qazsedcft on Sunday January 07 2018, @10:41AM (1 child)
It may seem like a lot but you have to realize that space is really, really large. The popular image of spaceships crossing a densely-packed asteroid belt and nearly colliding with many objects is ridiculous (not just because of the fighter jet physics). The mass of the entire asteroid belt is so small (4% of the mass of the Moon) and the volume so large that for all practical purposes it's empty space. You have to aim very precisely to intercept an asteroid.
The 46 million is similarly a figure that doesn't impress simply due to the sheer size of the solar system. It's much like saying 46 million drops of water in the ocean or 46 million mollecules of oxygen in the atmosphere.
(Score: 2) by takyon on Tuesday January 09 2018, @01:01AM
46 million a year (it appears these are objects 100 meters or more in diameter) is a nice get for our solar system.
In a few hundred years, if we dominate the solar system but interstellar travel is still difficult, we should do the best we can to redirect the interstellar asteroids so that they stay in our solar system indefinitely. That is interstellar money just flooding into our solar system, and we've let it fly right out since the dawn of humanity. It's almost time to take control of our solar system's gravitational borders and collect our birthright.
Yes, I am being serious. Why do you ask?
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]