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AK
2004-May-13, 05:52 AM
How many other interesting Trojans are there besides the "big three" orbiting Jupiter? Does Mars have many more? Any of significant size?

As for 5261 Eureka specifically, according to this orbit simulation (http://neo.jpl.nasa.gov/cgi-bin/db?name=5261) its orbit is inclined 20.3 degrees, which is significantly more than Mars' inclination. So how is this a Trojan? Wouldn't it spend the majority of its time outside the Lagrange point, which it would only inhabit at the two points in its orbit that it crosses Mars' border?

eburacum45
2004-May-13, 08:50 AM
Not exactly an answer to your query, but this page of mine lists the known Martian trojans
(it is fiction, so don't take it too seriously)
Eureka
1998 VF31
1998 QH56
1998 SD4
2001 DH47
2001 FG24
2001 FR127

http://www.orionsarm.com/historical/Eurekan_Cybercracy.html

umop ap!sdn
2004-May-13, 09:00 AM
NASA's now defunct ADC site had a catalog of asteroids (which appears to still be available here (ftp://ftp.lowell.edu/pub/elgb/astorb.dat.gz)) but sorting them out would require plotting the orbits on computer. It gave me a figure of over 700 in the right range to be Jupiter Trojans (SMA of 4.950 - 5.455 AU). They're actually pretty loosely clustered around the Lagrange points, so the gravitational forces mustn't be restraining them very much.

eburacum45
2004-May-13, 09:15 AM
And this one is a Neptune trojan;
http://www.spacedaily.com/news/kuiper-03a.html

the Jupiter trojans page
http://www.ifa.hawaii.edu/~sheppard/satellites/trojan.html

Eroica
2004-May-13, 04:20 PM
How many other interesting Trojans are there besides the "big three" orbiting Jupiter?
Nitpick: Jupiter's Trojans orbit the Sun, not Jupiter!


As for 5261 Eureka specifically ... its orbit is inclined 20.3 degrees, which is significantly more than Mars' inclination. So how is this a Trojan?
Beats me! :-k

JohnOwens
2004-May-13, 04:49 PM
How many other interesting Trojans are there besides the "big three" orbiting Jupiter? Nitpick: Jupiter's Trojans orbit the Sun, not Jupiter!
Actually, they orbit both. That's the nature of the equilateral triangle formed by a Trojan/L4/L5 configuration. The period of their orbit around Jupiter is the same as the orbit around the Sun. Oh, sure, the deflection from the Sun's gravity might be a wee bit larger than the deflection from Jupiter's, but Jupiter's little nudge is what keeps them at the Trojan points.
For more interesting possibilities that can confuse you about what's orbiting what, google "kemplerer rosette".

bobjohnston
2004-May-13, 08:52 PM
Here are counts of known asteroids/outer solar system minor planets that are Trojans:
with Jupiter, 1,655
with Neptune, one
with Mars, seven were formerly listed by the Minor Planet Center but this list was withdrawn pending clarification of the dynamics involved (one is Eureka).

There is one asteroid described as co-orbital with the Earth (2002 AA29), but it is not a Trojan asteroid.

Several Trojan satellites exist in the Saturn system.

Kullat Nunu
2004-May-13, 09:05 PM
There is one asteroid described as co-orbital with the Earth (2002 AA29), but it is not a Trojan asteroid.

The status of Cruithne has been a bit unclear to me.
Is it so that it is not currently a true quasisatellite/co-orbital but will been so periodically?


Several Trojan satellites exist in the Saturn system.

Yes, Telesto and Calypso are trojans of Tethys, and Helene Dione's.
Janus and Epimetheus are co-orbitals.

Eroica
2004-May-14, 11:57 AM
How many other interesting Trojans are there besides the "big three" orbiting Jupiter? Nitpick: Jupiter's Trojans orbit the Sun, not Jupiter!
Actually, they orbit both. That's the nature of the equilateral triangle formed by a Trojan/L4/L5 configuration. The period of their orbit around Jupiter is the same as the orbit around the Sun.
You seem to be employing the word orbit in an acceptation with which I'm not familiar. :D