Its beginning to look as if planetary systems are commonplace but some are
very weird systems with gas giants in odd orbits. At least one system with
gas giants in Sol-type orbits has been found and a Mars sized planet has
been discovered so small rocky planets so exist out there. Mostly the
technology cannot detect anything much smaller than Saturn. Apparently, its
getting better though. John
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
> John Lambshead wrote:
John,
Can you cite your sources on these finding, esp the Mars-sized planet?
And exactly what you mean by "Sol-type orbits"? Thanks.
Adrea Lommen from UC reported at the American Astronomical Society meeting in
Washington recently that she had detected a Mars sized planet by its
interference with radio waves as it orbited a pulsar - the first proof
I believe of any small rocky planet outside the solar system. The 74 or so
planets found so far outside the solar system are I think gas giants (need
to be big to be detected - the pulsar is a lucky break). Many have
eccentric orbits that would prevent the formation of small rocky planets in
the biozone. 47 Ursea Majoris has two large gas giants in circular orbits
outside the biozone but Gregory Laughlin (UC same conference) has calculated
that they are still too close in so the asteroid belt would be in the biozone.
Gas giants form the asteroid belt by preventing agglutination into a planet.
I suppose if a gas giant had a circular orbit in the biozone then a large moon
might be able to support life.
John
> John Lambshead wrote:
> has been
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
Actually, the first exo-solar planets discovered were around pulsars
(neutron stars). PSR B1257+12 is believed to have three planets, the
first was discovered in 1991.
Distance (au's): 0.19 0.36 0.47 Period (days): 25.34 66.54 98.22
Mass (Earth = 1): 0.019 4.3 3.6
Orbital Eccentricity: 0.0 0.018 0.026
There have been several other discoveries of planets around pulsars, but one
was disproven. What the thought was a planet was actually the interaction of
the emissions from the pulsar and our sun.
As for gas giants in bio-zones, just wait tell the sun turns into a red
giant, because Saturn's moon Titan could be habitable...
> John Lambshead wrote:
Thanks. I am not familiar with the pulsar planets end of life; more involved
with the extrasolar planets around stars more or less like our own studies
these days. But you haven't really explained what you
mean by "Sol-like orbits" from your first post. Or, if you did, I didn't
understand the explanation you gave.
> >John
Seems Beth has got competition in the alien biology department
;-)
G'day,
> > Head, Nematode Research Group
An expert on Terellians!
On Sat, 23 Feb 2002 10:50:46 +0100 KH.Ranitzsch@t-online.de
> (K.H.Ranitzsch) writes:
> Oh I just meant a layout like the solar system, rocky planets inwards
> And they are all in neat nearly circular orbits (except Pluto -
Its a very convenient arrangement for life on earth, but then that is why
there is life on earth (someone wins the lottery).
If I have understood the astronomers correctly, bearing in mind I am a
biologist, then this convenient arrangement may not be the norm, or even
that common.
John
> Thanks. I am not familiar with the pulsar planets end of life; more
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
Zoologists love playing alien biology games. There is plenty of it on Earth.
Much of Earth biology is more alien than was dreamed off 100 years ago. John
> At 10:50 23/02/2002 +0100, you wrote:
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
Dear Beth Absolutely. I have a paper due out soon calculating 1 X 10 to the
power 19 freeliving nematodes on earth. This is the worlds most successful
animal. Four out of ever five animals on Earth is a nematode worm (most of the
rest are insects). Speciartion is unknown but its somewhere between 1,000000
and 100,000000
(probably the former). I work on deep sea nems mostly - they are found
free-living from oceanic trenches to Mount Everest in sediments and
parasitise every other large plant and animal. These are the Masters of the
Universe.
Nematodes will feed on the body of the last dead man on earth. John
> > > Head, Nematode Research Group
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
I'll bite. Whats a Teterra, er tererurulia er, thingy? John
> At 21:07 23/02/2002 -0500, you wrote:
Dr PJD Lambshead Head, Nematode Research Group Department of Zoology The
Natural History Museum London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
From: John Lambshead pjdl@nhm.ac.uk
> <snip> 10E19 freeliving nematodes on earth. This is the worlds most
Can't be *that* successful--they don't buy minis.
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