
NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Cel nav in space
From: Frank Reed CT
Date: 2005 Jan 5, 17:52 EST
From: Frank Reed CT
Date: 2005 Jan 5, 17:52 EST
Chas wrote:
"Two Voyager space probes launched during the 70's are still on the
JPL
active mission list and NASA schedules regular communications sessions with
them. They currently are well past the orbit of Pluto and may be considered
to be in intersteller space."
active mission list and NASA schedules regular communications sessions with
them. They currently are well past the orbit of Pluto and may be considered
to be in intersteller space."
The two Pioneers are out there, also, but JPL no longer attempts to contact
them.
And:
"I have been considering asking the space navigators at NASA if they have
noticed any anomolities in their trajectories as the gravitational influence
of the sun deminishes. According to Einstein, space can actually be shaped
by gravity fields."
"I have been considering asking the space navigators at NASA if they have
noticed any anomolities in their trajectories as the gravitational influence
of the sun deminishes. According to Einstein, space can actually be shaped
by gravity fields."
There are observed tiny anomalies in the trajectories of the Pioneer
probes. Here's a link to an article: http://www.space.com/scienceastronomy/mystery_monday_041018.html
And:
"Maybe we might have enough knowledge navigate about our Milky Way galaxy
but heading out to explore another galaxy who be a greatest venture into the
unknown since Columbus sailed over the 'edge of the earth'."
"Maybe we might have enough knowledge navigate about our Milky Way galaxy
but heading out to explore another galaxy who be a greatest venture into the
unknown since Columbus sailed over the 'edge of the earth'."
Ya know, it's a funny thing really, but we can map *other* galaxies much
more easily than we can map our own. The large-scale structure of the nearest
galaxies are known in considerable detail and there is no limit in principle to
extending those maps. But the overall structure of own galaxy is still largely
unknown. For example, there was solid evidence of black holes at the centers of
other galaxies years before evidence was available of a large black hole at the
center of the Milky Way (there is now solid evidence of that, too). It's so
difficult to map the Milky Way because we're in the middle of all the dust. When
we look at the night sky and the visible Milky Way, we're seeing only a few
percent of the whole thing. With most other galaxies, we can see just about
everything.
And:
"We would need to travel there at light speed, if that's possible. Would
sightings need to be corrected for relativistic effects? "
"We would need to travel there at light speed, if that's possible. Would
sightings need to be corrected for relativistic effects? "
We do already! Aberration of star light is pre-computed in the star tables
in the Nautical Almanac (see my post from 12-30-2004 on sextant science). If you
were travelling at 90% of the speed of light towards Orion's belt, for example,
the angle between Polaris and the belt would be only 26 degrees (it's usually
90!) due to aberration.
And:
"How will we correct sightings for light being bent around black
holes?"
You have to get really close to a black hole before this is an issue. But
astronomers can and do correct for gravitational deflection of light on a
routine basis when they need to. The European Hipparcos mission carefully
measured the exact positions of thousands of stars. Deflection of starlight by
the Sun's gravitation was an issue at angles up to 90 degrees away from the Sun
and even the deflection by Jupiter's much weaker gravitational field had to be
taken into account. But gravity, even relativistic gravity, is really very
simple and predictable. Lucky for us.
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars