New Discoveries - Extraplanetary, deep space, etc.

Palomar · 2002-08-21 09:09:24

*I thought this web site might be of some benefit to those new to and interested in amateur astronomy; I recommended it to a cousin, who highly recommends it:
http://www.absolutebeginnersastronomy.com/
--Cindy
Speaking of astronomy, are you still planning to get a new scope? I want to get one but everytime I get close the cheapskate comes out of my body and runs off with my checkbook. I was reading about the "Zodiacal light" the other night. The impression I got was that the Zodiacal light was different from the Milky Way. Do you have any idea what that is? Anyways, I'd love to be in an area so dark and free from light pollution that the Milky Way actually casts light on the ground. Light pollution really sucks.

*Phobos: Yes, Zodiacal Light is different from the Milky Way. I'll post a description of what Zodiacal Light is, later today...[and no, I haven't yet gotten a larger telescope]...

--Cindy

Palomar · 2002-08-21 19:42:55

*Here's what my little pet book, _Stars: A Golden Guide_ says about Zodiacal Light [it'll be quicker to quote the book than try and summarize it in my own words]:

"Zodiacal light is so called because the triangular band of light which extends from the horizon halfway to the zenith follows the Earth's ecliptic and hence passes through the constellations which make up the Zodiac. This very faint glowing light is best observed in the early evenings of March and April, and just before dawn in September and October. In the tropics it is seen more often. On a clear, moonless night its brightest areas may outshine the Milky Way.

Zodiacal light is apparently sunlight reflected from meteoric particles existing in areas near the plane of the ecliptic. Though meteoric particles are concentrated in this region, they are widely separated. If the particles were of pinhead size and 5 miles apart, there would be enough within the Earth's orbit to reflect the amount of light usually observed.

The zodiacal light seems to widen into a spot some 10 degrees in diameter at a place just opposite the sun. This faint haze of light that moves opposite the sun is known as Gegenschein or Counterglow.

The area of zodiacal light called Gegenschein may owe its increased light to the fact that meteoric particles directly opposite the sun reflect toward us more sunlight than is reflected by particles in portions of the band that are not directly opposite the sun." ::End quote::

The Milky Way is "simply" the denser part of our galaxy, i.e. when you see it in the summer sky [and yes, it's best viewed away from artificial light] you are looking toward the center of our galaxy; the stars are much denser toward the core of our galaxy than they are where we're at [near an edge].

--Cindy

Phobos · 2002-08-21 22:09:18

Zodiacal light is apparently sunlight reflected from meteoric particles existing in areas near the plane of the ecliptic. Though meteoric particles are concentrated in this region, they are widely separated. If the particles were of pinhead size and 5 miles apart, there would be enough within the Earth's orbit to reflect the amount of light usually observed.
The zodiacal light seems to widen into a spot some 10 degrees in diameter at a place just opposite the sun. This faint haze of light that moves opposite the sun is known as Gegenschein or Counterglow.

Wow, nice info. I was thinking that maybe the Zodiacal light had something to do with the light reflecting off of the planets but so much for that . The next time I go out into the desert during the months you described I'm going to try to observe the Zodiacal light. Have you ever seen it?

Palomar · 2002-08-23 08:27:44

The next time I go out into the desert during the months you described I'm going to try to observe the Zodiacal light. Have you ever seen it?

*I don't think I've ever seen zodiacal light, no. There's another naked-eye phenomenon you can watch for...have you heard of Earthshine?

--Cindy

Josh Cryer · 2002-08-23 14:36:57

Hasn't zodiacal light light been impossible to see in most places for years due to light pollution? I've never seen it, but I have lived in or around cities most of my life.

Looking at the night time MODIS images, one must wish they were in a place on Earth where light pollution doesn't prodominate.

Palomar · 2002-08-23 14:50:21

Hasn't zodiacal light light been impossible to see in most places for years due to light pollution?

*Probably.

--Cindy

Palomar · 2002-08-23 15:30:46

Cindy, yes! The Martian crustal magnetic field is patchy. It's really quite strong in some areas ... strong enough to reach up high above the surface and actually shield the atmosphere from solar wind "erosion", called sputtering. While in other regions it is very weak.
Actually Josh, I believe now that Mars does have a global magnetic field, though very much weaker than Earth's. This is an important point because relatively young lava flows have been identified on Mars. In fact, they're so young that they might have occurred only thousands of years ago! Though figures of up to ten million years are also possible. In either case, it means Mars must still be volcanically active. And this would tie in with the magnetic field evidence, since it is believed that a molten interior is associated with the production of a magnetic field.
All this makes me think Mars is a dynamic place. At the moment it's sleeping and appears quite dull. But I suspect all of its spectacular activity is not necessarily confined to its halcyon past! I think it's a place of cyclical activity and anything could happen.

*I've been thinking about this, and I've got a few more questions/comments:

Does the moon have a magnetic field? Even if it doesn't, the Apollo astronauts had very short stays on the lunar surface...no time for an absent or erratic magnetic field to affect them.

I'm wondering how, if at all, Mars' weird magnetic field will affect the crew going there. I'm thinking along the lines of EQUILIBRIUM and the inner-ear fluid which can cause vertigo or maintain equilibrium.

Does our magnetic field influence our inner-ear fluid, and hence equilibrium status [or lack of it]? Shaun previously mentioned homing pigeons would be absolutely disoriented on Mars.

Just curious.

--Cindy

Josh Cryer · 2002-08-23 17:34:37

Does the moon have a magnetic field? Even if it doesn't, the Apollo astronauts had very short stays on the lunar surface...no time for an absent or erratic magnetic field to affect them.

Interestingly, the Moon does have a very small magentic field. Although it's not strong enough to create a magnetosphere that can deflect particles, there are some areas where the magnetized crust actually create pocket magnetospheres hundreds of kilometers across!

So on Luna we have areas where the solar wind is deflected naturally. Prime places to inhabit.

I'm wondering how, if at all, Mars' weird magnetic field will affect the crew going there. I'm thinking along the lines of EQUILIBRIUM and the inner-ear fluid which can cause vertigo or maintain equilibrium.

I find it interesting that we have yet to detect a real magnetic field on Mars (as far as I know), we've only found remnant fields. Personally, I don't think humans will have problems dealing with that. I personally think humans are the animals least connected to nature (save our connection to 1G).

But Shaun is right about a magnetic field affecting certain animals. Most notably birds (not just homing pigeons- all migratory birds).

Shaun Barrett · 2002-08-23 19:57:25

Josh, you've got me worried about this Martian magnetic field thing!
In recent years, I had accepted that the only field on Mars was a patchy, remnant, crustal field. But lately, in reading through one or two websites, I've been getting the impression that I was wrong.
My current understanding is that there is an extremely weak global field of 1/800th to maybe 1/500th the strength of Earth's field. Superimposed on this, are the crustal remnants of a previously much stronger global field which is assumed to have existed early in the planet's history. Apparently, in some places, the remnant fields are still nearly equal to Earth's current global field, though most are weaker.
Now, I may well be misinterpreting what I've been browsing through, and I'm ready and willing to be corrected. In fact, if anyone has the 'low-down' on the latest data about Mars' magnetic field, I'm all ears!!

P.S. It's just occurred to me, since Mars appears to have had polarity reversals in the past, that maybe we've caught her in the middle of one right now.
When Earth has a polarity reversal, there is a time period in the middle when there is little or no field at all to speak of. What if Mars normally has a quite respectable global magnetic field? .... Maybe not anything like Earth's strength of course, but respectable just the same. It could be we're seeing it at just the wrong time!
I know, probability is against us showing up at just the wrong moment. But it can happen. Look at how Mariner 9 arrived in orbit around Mars in 1971, in the middle of a planetwide dust storm!
As Confucius say: "S**t happens!"

Josh Cryer · 2002-08-23 23:42:27

My current understanding is that there is an extremely weak global field of 1/800th to maybe 1/500th the strength of Earth's field.

With some digging about, I found evidence to suggest the same. My focus was on the offical MAGER site, which at first glance says nothing about this global field.

Apparently, in some places, the remnant fields are still nearly equal to Earth's current global field, though most are weaker.

Yes! I saw this too (so here's a confirmation for ya), and I swear I jumped out of my seat. My inital impression was that the remnant fields were too small to create a mini-magnetosphere, boy was I elated when I learnt I was wrong!

This is good news for colonization. Humans need magnetospheres! Before, whenever I look at topology or images of Mars, I would ponder where the best place to colonize would be. Well, clearly the answer to that is obvious now.

It's just occurred to me, since Mars appears to have had polarity reversals in the past, that maybe we've caught her in the middle of one right now. When Earth has a polarity reversal, there is a time period in the middle when there is little or no field at all to speak of. What if Mars normally has a quite respectable global magnetic field?

I wish you were right, but I'm compelled to believe otherwise. Three reasons:

First, there is no volcanic activity.

Second, Mars has no large moon, one large enough to keep an internal dynamo going by gravitational forces.

Third, the commonly accepted reason for Martian atmospheric density loss, is solar erosion, so assuming we are witnessing a pole reversal (one that is pretty recent), we will have to change our whole understanding of where the atmosphere went. And I don't think there is solution to this problem other than solar erosion...

Palomar · 2002-08-24 07:57:39

*Interesting reading:

http://story.news.yahoo.com/fc?cid=....teroids

--Cindy

Phobos · 2002-08-24 17:43:25

I'm wondering how, if at all, Mars' weird magnetic field will affect the crew going there. I'm thinking along the lines of EQUILIBRIUM and the inner-ear fluid which can cause vertigo or maintain equilibrium.
Does our magnetic field influence our inner-ear fluid, and hence equilibrium status [or lack of it]? Shaun previously mentioned homing pigeons would be absolutely disoriented on Mars.
Just curious.

I went and did a little fact finding on homing pigeons and it's apparently not set in stone that they need the Earth's magnetic field to navigate even though that is the most popular theory. I doubt if our equilibrium depends on any kind of magnetic field. If that was the case the astronauts who went to the Moon should have been having a hard time standing up. Gravity might help in that sense though considering that something like half of the astronauts who go into space get motion sickness.

*Interesting reading:
http://story.news.yahoo.com/fc?cid=....teroids
--Cindy

There's been a lot of speculation as to why there seems to be no other life on Earth but those that are based on our DNA/RNA. People sometimes argue that the apparent fact that no other life developed independently of the current strain means life is rare in the universe. This asteroid might change all of that though. They seem to think that it pretty much wiped out most of the life on Earth so maybe there were other life forms that developed independently of each other on Earth?

Phobos · 2002-08-24 17:45:40

Bumping up lost messages.

Adrian · 2002-08-25 04:29:24

'Bumping up lost messages'? Have posts disappeared from this forum too?

About human balance: I'm pretty much 100% certain that our sense of balance has absolutely nothing to do with the Earth's magnetic field (I Am A Biologist). First off, we know from extensive physiological experiments that our sense of balance is governed by proprioception, vision, our semi-circular canals and otoliths. I'm not aware of any evidence pointing towards an organ in the body that responds to the Earth's EM field, and even if it did, exactly how would it work?

Secondly, what's the point of using the magnetic field when we have so many other, better and more accurate ways of sensing balance? Evolutionarily speaking, we're doing just fine.

Thirdly, and I just thought of this, when humans are put into a Magnetic Resonance Imaging scanner, which exposes us to a magnetic field up to 50,000 times that of Earth's, we don't report any feelings of losing balance.

As for pigeons, I'll agree with Phobos. I don't know whether they use magnetic fields or not, but I doubt it. An interesting thing about pigeons is that they have an absolutely astounding visual memory, better than ours in fact (there are some pretty funny experiments that proved this, putting pigeons in front of projector screens and so forth). So I'd think that they manage to navigate so well simply by using visual landmarks - after all, that's how we do it.

There was some talk of whales navigating via magnetic fields - I'm less familiar with this and I think the evidence tends to centre on the locations of beached whales correlating with deposits of metal ores (i.e. perturbations in the magnetic field). As fars as I know, nothing has been proven concerning this.

Phobos · 2002-08-25 17:58:08

As for pigeons, I'll agree with Phobos. I don't know whether they use magnetic fields or not, but I doubt it. An interesting thing about pigeons is that they have an absolutely astounding visual memory, better than ours in fact (there are some pretty funny experiments that proved this, putting pigeons in front of projector screens and so forth). So I'd think that they manage to navigate so well simply by using visual landmarks - after all, that's how we do it.

This reminded me of some experiments I read about in WWII where some people tried to build missiles that used pigeons as pilots. They trained the pigeons to basically fly toward certain shapes that resembled the targets by having the pigeons peck at a board that steered the missile toward the target. It's not really that far fetched of an idea considering that the Coast Guard sometimes uses pigeons who peck at a board in the direction they see something.

Josh Cryer · 2002-08-25 18:13:13

Many migratory animals do show a correlation between the magnetic field and their migratory path. I did a simple search on Google and got lots of hits pertaining to the subject.

Palomar · 2002-09-13 08:45:49

*Earth's "new moon" is space junk [my sister sent this article to me]. I thought everything from the 1960s missions would've decayed in orbit and burned up by now!

http://news.bbc.co.uk/go/em/fr/-/2/hi/s … 253385.stm

--Cindy

Phobos · 2002-09-14 15:20:09

*Earth's "new moon" is space junk [my sister sent this article to me]. I thought everything from the 1960s missions would've decayed in orbit and burned up by now!
http://news.bbc.co.uk/go/em/fr/-/2/hi/s … 253385.stm
--Cindy

Cindy, how can that "moon" be an Apollo rocket booster when we clearly never went to the Moon? I suspect this is another NASA hoax to throw us off the track of their dastardly deeds. Remember to wear the metal hat and keep those evil NASA brain washing waves at bay!

Adrian · 2002-09-14 15:35:10

Ah Josh, you put it exactly right - they show a correlation. Now, even if the correlation is strong, it does not necessarily imply causation. For example, you could say that watching TV extends lifespan, because in countries that watch a lot of TV (i.e. developed Western nations) the lifespan is longer - but it wouldn't be true.

I'm not discounting the possibility that some animals might sense and use magnetic fields for navigation - I just haven't seen any good conclusive evidence to suggest it yet.

Palomar · 2002-09-14 15:46:46

*Earth's "new moon" is space junk [my sister sent this article to me]. I thought everything from the 1960s missions would've decayed in orbit and burned up by now!
http://news.bbc.co.uk/go/em/fr/-/2/hi/s … 253385.stm
--Cindy
Cindy, how can that "moon" be an Apollo rocket booster when we clearly never went to the Moon? I suspect this is another NASA hoax to throw us off the track of their dastardly deeds. Remember to wear the metal hat and keep those evil NASA brain washing waves at bay!

*OMG, Phobos! You're right! What in tarnation was I thinking?! Geesh, maybe I'd better start putting the metal helmet on UNDERNEATH my powdered wig! :0

The NASA waves are :::powerful:::!! Arrrghh!

Voltaire, SAAAAAAAVE ME!!!

--Cindy

Phobos · 2002-09-15 02:39:17

*OMG, Phobos! You're right! What in tarnation was I thinking?! Geesh, maybe I'd better start putting the metal helmet on UNDERNEATH my powdered wig!
The NASA waves are :::powerful:::!! Arrrghh!
Voltaire, SAAAAAAAVE ME!!!
--Cindy

Might be hard to keep all of those antennae from poking up through the wig. Actually I'm thinking this booster might be an artifact that proves NASA sent Free Masons to Mars in the 1960s. Just seems a little fishy doesn't it that NASA would send an Apollo part past the moon!! Maybe we should write a book and bring the truth to the masses and fatten our bank accounts!

Shaun Barrett · 2002-09-15 06:05:37

Forget Voltaire, Cindy!
Recent research has shown he was an early NASA employee!!
Trust no-one!
???

Josh Cryer · 2002-09-15 10:48:40

I always try to be scientific with my wording, Adrian. Since I'm usually regurgitating what I've read, and not necessarily understanding it.

But you're right, I really haven't found anything to say for sure exactly what is the sole contributor (assuming there is) to migratory habits; I'm actually confident it's various things, not merely one simple process. Life is extremely redundant. From DNA (which has three copies of itself, encoded in a CRC-esque algorithm), to basic senses. With a missed code fragment, DNA still manages to work. And without a sense (or two), we can still function relatively well.

If I recall correctly, there was a thing done where magnets were basically taped to the heads of homing pigeons. I believe it had no effect.

As to the Apollo thing. I have two wishes for it, to be honest. What I'd really like to see, is for us to attach a space tug of sorts to it, and put it in a safe orbit around the Earth, until humanity progresses to a point where we can, say, put it in a museum on Luna.

But if we can't do that, it'd be really awesome to see it come crashing down on the moon.

Palomar · 2002-09-15 11:28:38

*OMG, Phobos! You're right! What in tarnation was I thinking?! Geesh, maybe I'd better start putting the metal helmet on UNDERNEATH my powdered wig!
--Cindy
Might be hard to keep all of those antennae from poking up through the wig.

*Well, well. Looks like I have started a new fashion trend! Yves St. Laurent, MOVE OVER

--Cindy

Shaun Barrett · 2002-09-16 01:37:41

Regarding the new "moon" we've acquired.
What if it's a small asteroid we've trapped in orbit around us? What if it's just a fluke that its orbit matches one that could be associated with an old Saturn V third stage?
If it's an asteroid full of volatiles, maybe it would be worth nudging it away from a collision with the Moon and steering it into a closer orbit for future utilisation(? ). I guess it depends on the mass of volatiles involved.
Anyway, my main point is to ask if it's possible to point the Hubble telescope at it for a positive identification. Or would those in the line waiting for 'telescope time' kick up a stink about it?
:0

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