stephen55
Literotica Guru
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- Jan 6, 2010
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No!! Not that kind of Trojan!!
There is a "cool science" thread over at the GB but I find going there (the GB) often becomes a toxic experience, so I thought I'd post this cool science bit here instead.
A group of Canadian astronomers has discovered that Earth has it's own Trojan asteroid. Trojans in astronomy are bodies (natural satellites or minor planets) that go around a planet or moon, in the same orbit as the planet or moon, but at a fixed place in that orbit, either 60 degrees ahead of or behind the main planet or moon, or direcly opposite at 180 degrees. These gravitationally stable points are called L3, L4 and L5. (The "L" is for Lagrange, an eighteenth century French mathematician and astronomer who predicted their existence.)
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Lagrange_very_massive.svg/400px-Lagrange_very_massive.svg.png
The Sun-Earth Lagrangian points
This asteroid, known so far as 2010 TK7, is about 300 meters in diameter and sits about 80 million kilometers from Earth, at the Sun-Earth L4 point, so it orbits 60 degrees ahead of the Earth. Unlike the Moon, it is not a satellite of Earth as it doesn't orbit the Earth.
http://ca.news.yahoo.com/earth-secondary-moon-discovered-140058013.html
Technically, the asteroid orbits the common center of mass of itself, the Earth and the sun. A Lagrange point is where the combined forces of gravity due to the two larger objects (in this case, the Earth and the sun) precisely allows the smaller object to orbit with them. It is thus similar to a geosynchronous orbit which keeps some Earth artificial satellites in one position above the earth.
Earth Trojans could be found at L4 or L5, but not at L3. The Sun-Earth L3 point is not gravitationally stable due to the gravitational pull of Venus which comes within 45 million kilometers of our L3 every twenty months.
Of note, Lagrangian points 1 and 2 are both great places to park an artificial satellite. L1 will allow a satellite to constantly view the sun. The Solar and Heliospheric Observatory (SOHO) is at Sun-Earth L1. L1 also makes a great place to park a space station that might be needed to support a moon colony.
L2 is a great place to observe the universe. Several space observatories are already there and will soon be joined by NASA's James Webb Space Telescope and the European Space Agency's Gaia mission.
There is a "cool science" thread over at the GB but I find going there (the GB) often becomes a toxic experience, so I thought I'd post this cool science bit here instead.
A group of Canadian astronomers has discovered that Earth has it's own Trojan asteroid. Trojans in astronomy are bodies (natural satellites or minor planets) that go around a planet or moon, in the same orbit as the planet or moon, but at a fixed place in that orbit, either 60 degrees ahead of or behind the main planet or moon, or direcly opposite at 180 degrees. These gravitationally stable points are called L3, L4 and L5. (The "L" is for Lagrange, an eighteenth century French mathematician and astronomer who predicted their existence.)
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Lagrange_very_massive.svg/400px-Lagrange_very_massive.svg.png
The Sun-Earth Lagrangian points
This asteroid, known so far as 2010 TK7, is about 300 meters in diameter and sits about 80 million kilometers from Earth, at the Sun-Earth L4 point, so it orbits 60 degrees ahead of the Earth. Unlike the Moon, it is not a satellite of Earth as it doesn't orbit the Earth.
http://ca.news.yahoo.com/earth-secondary-moon-discovered-140058013.html
Technically, the asteroid orbits the common center of mass of itself, the Earth and the sun. A Lagrange point is where the combined forces of gravity due to the two larger objects (in this case, the Earth and the sun) precisely allows the smaller object to orbit with them. It is thus similar to a geosynchronous orbit which keeps some Earth artificial satellites in one position above the earth.
Earth Trojans could be found at L4 or L5, but not at L3. The Sun-Earth L3 point is not gravitationally stable due to the gravitational pull of Venus which comes within 45 million kilometers of our L3 every twenty months.
Of note, Lagrangian points 1 and 2 are both great places to park an artificial satellite. L1 will allow a satellite to constantly view the sun. The Solar and Heliospheric Observatory (SOHO) is at Sun-Earth L1. L1 also makes a great place to park a space station that might be needed to support a moon colony.
L2 is a great place to observe the universe. Several space observatories are already there and will soon be joined by NASA's James Webb Space Telescope and the European Space Agency's Gaia mission.
Not big enough?
