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ToSeek
2006-Jun-15, 08:58 PM
Neptune Linked to Potential Swarm of Asteroids (http://www.space.com/scienceastronomy/060615_neptune_trojans.html)


Astronomers have detected three new rocky bodies which share the same orbit as Neptune as it travels around the Sun.

The finding, detailed in the June 16 issue of the journal Science, brings the total number of the gas giant's asteroid companions, or “Trojans,” up to four.

The highly inclined orbit of one of them supports the hypothesis that the Neptune Trojans were captured from a much larger asteroid "cloud" that surrounds the planet, and that they are not the broken remains of some larger object as some scientists have speculated.

Apparently we already knew it had one. (http://www.bautforum.com/showthread.php?t=20731)

Blob
2006-Jun-15, 09:04 PM
The story is also here http://www.dtm.ciw.edu/sheppard/trojans/

http://www.cfa.harvard.edu/iau/lists/NeptuneTrojans.html

tony873004
2006-Jun-16, 12:24 AM
A diagram of the orbit of Neptune's trojans in a rotating frame. Initial conditions courtesy of JPL.
http://orbitsimulator.com/BA/neptunetrojans.GIF

Blob
2006-Jun-16, 01:54 AM
The recently discovered Neptune Trojans are only the fourth stable group of asteroids observed around the Sun. The others are the Kuiper Belt just beyond Neptune, the Jupiter Trojans, and the main asteroid belt between Mars and Jupiter. Evidence suggests that the Neptune Trojans are more numerous than either the asteroids in the main belt or the Jupiter Trojans, but they are hard to observe because they are so far away from the Sun. Astronomers therefore require the largest telescopes in the world equipped with sensitive digital cameras to detect them.

Read more (http://www.carnegieinstitution.org/neptune_trojans/default.html)

publiusr
2006-Jun-29, 08:58 PM
Are there any asteroid orbits that pass through these areas?

Blob
2006-Jul-23, 02:23 PM
A Thick Cloud of Neptune Trojans and Their Colours
The dynamical and physical properties of asteroids offer one of the few constraints on the formation, evolution and migration of the giant planets. Trojan asteroids share a planet's semi-major axis but lead or follow it by about 60 degrees near the two triangular Lagrangian points of gravitational equilibrium. Here we report the discovery of a high inclination Neptune Trojan, 2005 TN53. This demonstrates that the Neptune Trojan population occupies a thick disk which is indicative of ``freeze-in'' capture instead of in-situ or collisional formation. The Neptune Trojans appear to have a population several times larger than the Jupiter Trojans. Our colour measurements show that Neptune Trojans have statistically indistinguishable slightly red colours suggesting they had a common formation and evolutionary history and are distinct from the classical Kuiper Belt objects.

Read more (http://www.dtm.ciw.edu/sheppard/pub/Sheppard06NepTrojans.pdf) (PDF)

eburacum45
2006-Jul-23, 03:03 PM
The recently discovered Neptune Trojans are only the fourth stable group of asteroids observed around the Sun. The others are the Kuiper Belt just beyond Neptune, the Jupiter Trojans, and the main asteroid belt between Mars and Jupiter.
Don't forget Eureka and the Martian Trojans...
http://en.wikipedia.org/wiki/5261_Eureka

Blob
2006-Jul-23, 03:17 PM
Hum,
tnx, i was aware of them.

Here is an amusing link to a list of all confirmed Martian asteroids.
http://cfa-www.harvard.edu/iau/lists/MarsTrojans.html

eburacum45
2006-Jul-23, 04:22 PM
heh...
I wonder what kind of ill-informed speculations they were.

Blob
2006-Jul-23, 06:47 PM
Hum,
Perhaps the observations were sparse, or the orbit arcs were short etc

(As in post http://www.bautforum.com/showthread.php?t=44649 )

tony873004
2006-Jul-23, 09:21 PM
Perhaps it is because only
1999 UJ7
1998 VF31
Eureka
are truly trojan asteroids of Mars

5 other asteroids are mistakenly referred to as martian trojans:
2001 DH47
2001 FG24
1998 QH56
2001 FR127
1998 SD4
But they are not trapped in the L4 or L5 points. Rather, they are free to drift past Mars in a rotating frame of reference.
http://orbitsimulator.com/gravity/marstrojans.GIF

eburacum45
2006-Jul-24, 06:06 AM
So a more accurate description might be Near Mars Objects then.

Blob
2006-Jul-24, 01:04 PM
@eburacum45
or just `asteroids`

@tony873004
BTW good work on that gif.