[meteorite-list] There IS an Earth Trojan Asteroid (probably)!

[Sterling K. Webb]

Hi,


In 1980, there was a search down to magnitude 14
that turned up nothing at the Earth's Trojan points.

But there ARE Earth Trojans, or at least candidate
objects.  It takes a long series of observations to
verify a true Trojan orbit, and they're doing that.
In a search that is ongoing (slowly, one gathers) and
that will scan 9 square degrees down to magnitude 22,
there are good candidate objects.  They "slew" the
telescope at the Earth Trojan rate, stars are sstreak,
regular asteroids are also streaks, but a Trojan is
pretty much a dot or oval.

photos of Earth Trojan candidates:
<http://www.astro.uwo.ca/~wiegert/etrojans/etrojans.html>

3753 Cruithne and several other asteroids share the Earth's
orbit but are not Trojans, but complicated "horseshoes":
<http://www.astro.uwo.ca/~wiegert/3753/3753.html>

There's no such thing as Googling enough...


Sterling K. Webb
---------------------------------------
"Matson, Robert" wrote:

> Hi Darren, Sterling and List,
>
> Sterling pondered about Earth Trojans:
>
> > Makes me wonder if somebody has ever tracked the orbital points > 60
> degrees ahead and behind the Earth...  Wouldn't it be great > to have
> Trojans of our own?
>
> Certainly astronomers have tried, but small objects at L4 and L5 would
> be hard to see due to a combination of range (150 million km), poorer
> phase angle, and a maximum sky elevation of perhaps 45 degrees at
> astronomical twilight -- lower when the sky is darker. It would be an
> interesting exercise to compute the maximum size an Earth Trojan could
> be and still have managed to go undetected.
>
> --Rob
> ___