Questions about space and a suggestion for a space observatory.

[Incendia]

Hello...Would we be able to detect a planet on that had an orbit at the same speed as Earth but was was always blocked from view by the sun?

 

Also...We have sent satellites to the further reaches of our solar system. I think it could be a a good idea to make one that orbits around the sun instead of the Earth in the opposite direction to Earth at a speed that would take it a long time [1/2/3/4 Earth years...preferable 1 EY] to revolve around the sun. Every time it passed the Earth we could remotely download the data it has collected and send people up to upgrade/repair it.

We could also have robonauts on it to operate it or automatically maintenance it when it is behind the sun. [unlikely though]

Why it could be a good idea:

Currently we can only see what our satellites can see and what is visible from Earth. As we cannot see through the sun we can only things on our side of the sun. Things on the other side however we cannot see. This mean we could miss activity such as comets passing our system once every thousand years or strange solar activity just because our planet is on the wrong side of the sun to see them. Sure we can simulate things...but simulations aren't as good as observation. The satellite could have two telescopes on it. One pointing to the outer solar system and outside it the other to the inner solar system. [Or several satellites could be sent out at once like a small cluster of 2/3/4 of them.]

We are capable of doing this. The satellite doesn't have to be state of the art with the newest and best things on it. It only has to be enough to give us the information to create the first panoramic image of our solar system.

[Janus]

Hello...Would we be able to detect a planet on that had an orbit at the same speed as Earth but was was always blocked from view by the sun?

 

Yes. its gravity would disturb the orbits of the other planets, as a result, even when those planets where on the the same side of the Sun as we are, they would be out of position. In addition, the other planets would disturb this planet's orbit and it would drift out of it's orbit until we could see it.

 

Also...We have sent satellites to the further reaches of our solar system. I think it could be a a good idea to make one that orbits around the sun instead of the Earth in the opposite direction to Earth at a speed that would take it a long time [1/2/3/4 Earth years...preferable 1 EY] to revolve around the sun. Every time it passed the Earth we could remotely download the data it has collected and send people up to upgrade/repair it.

We could also have robonauts on it to operate it or automatically maintenance it when it is behind the sun. [unlikely though]

Why it could be a good idea:

Currently we can only see what our satellites can see and what is visible from Earth. As we cannot see through the sun we can only things on our side of the sun. Things on the other side however we cannot see. This mean we could miss activity such as comets passing our system once every thousand years or strange solar activity just because our planet is on the wrong side of the sun to see them. Sure we can simulate things...but simulations aren't as good as observation. The satellite could have two telescopes on it. One pointing to the outer solar system and outside it the other to the inner solar system. [Or several satellites could be sent out at once like a small cluster of 2/3/4 of them.]

We are capable of doing this. The satellite doesn't have to be state of the art with the newest and best things on it. It only has to be enough to give us the information to create the first panoramic image of our solar system.

 

The Sun only blocks an area of the sky about 1/2 degree wide. Any comets would follow a hyperbolic or parabolic orbit, and we would see them at other points of the orbit. I really don't see any advantage to a solar orbiting station like the the one you suggest.

[Incendia]

...But what if it was already there...[As in it didn't only just appear...]

 

The atmosphere makes our view of things in space fuzzy and bad...there would be advantages of a solar orbiting stations like the one I am suggesting.

For instance being able to actually see parts of the sky and the sun at angles not visible from Earth...The advantages could be for study of the sun rather than study of outer space.

 

We have sent loads of space junk up...at least even if this did end up being space junk it would be better than the other space junk...

[Sisyphus]

...But what if it was already there...[As in it didn't only just appear...]

 

It would still disturb the orbits of the other planets, just like Earth does.

 

But anyway, there have been a bunch of solar orbiting missions:

 

http://en.wikipedia.org/wiki/Category:Solar_missions

[Incendia]

I was unaware...That-you for pointing them out Sisyphus.

 

[Did any of those flying in an opposite direction to Earth? I don't have time to read them all...]

[Sisyphus]

[Did any of those flying in an opposite direction to Earth? I don't have time to read them all...]

 

I don't know, but I very much doubt it. Remember that everything that we put into space starts out with the Earth's velocity, and any change in velocity (acceleration) requires a force. I reckon it would take a tremendous amount of fuel to "stop" something and put it in a "reverse" orbit like that, and I don't really see the point.

[Incendia]

I guess it wouldn't be worth it for such small achievements...

Edited November 20, 2010 by ProcuratorIncendia

[Airbrush]

I was unaware...That-you for pointing them out Sisyphus.

 

[Did any of those flying in an opposite direction to Earth? I don't have time to read them all...]

 

Probably not. What is gained by launching a satelite to orbit the Sun going the opposite direction? It would only be a tremendous waste of fuel to reverse directions, IF it was even possible. Far better to USE the velocity of the Earth going around the Sun.

[alpha2cen]

Sorry

I thought about it before.

 

See this sight

yoctosecond Saturday, October 30, 2010 5:48 PM

 

http://www.myspace.com/forums/t/4730501?PageIndex=2&SortOrder=0

 

Its reasonable, but require much money.

[Airbrush]

After thinking it over, I have come to the conclusion that the idea of launching a satellite to orbit the Sun in the direction OPPOSITE the Earth would be extreme insanity. Imagine the energy needed to accelerate away from Earth and reverse direction to the Earth's orbital speed (probably many miles per second) around the Sun in the OPPOSITE direction. This will also cause ALL debris in Earth's orbit that is moving the same direction around the Sun to become deadly meteors that will crash into your satelite at a closing speed of 30 miles per second or more.

 

Again I ask, why reverse direction?

Edited November 28, 2010 by Airbrush

[D H]

Regarding whether we would be able to detect a planet orbiting exactly opposite the Earth:

That assumes that a planet can orbit there. It can't, at least not for long. That is the Sun-Earth L3 Lagrange point, and that point is unstable. If a planet was at that point, one of three things would happen:

• Case 1: The planet is much less massive than the Earth. If the planet is not perfectly at the L3 point, in position and velocity, right down to the last decimal point, those deviations would grow with time. The L1 point is not stable. Even if it was exactly at that point, perturbations from other planets would induce some small deviation and the same result would arise.
  
• Case 2: The planet is much more massive than the Earth. This is the same as case 1, but in this case it is the Earth whose orbit is destabilized.
  
• Case 3: The planets are of comparable mass. Now both planets' orbits will be destabilized.

Bottom line: A planet cannot exist there. Asking whether we could detect such a planet doesn't make sense.

 

 

Regarding the cost of getting a satellite to the L3 point:

This is cheap. Very cheap. Here's how: Give the vehicle a velocity that just puts in on an escape trajectory in either a prograde or retrograde direction. The vehicle will escape the Earth's vicinity and independently orbit the Sun. A prograde burn will make the vehicle's orbit period about the Sun take a bit longer than one year while a retrograde burn will put the vehicle into an orbit slightly less than one year in duration. In either case the phase angle between the Earth and satellite will gradually increase over time without any additional maneuvering. When the phase angle is 180 degrees, perform another maneuver to put it into a pseudo orbit about the Sun-Earth L3 point.

Edited November 29, 2010 by D H

[alpha2cen]

Sorry

I thought about it before.

 

See this sight

yoctosecond Saturday, October 30, 2010 5:48 PM

 

http://www.myspace.c...x=2&SortOrder=0

 

Its reasonable, but require much money.

 

The satellite turn around the Mar is reasonable.

The solar intensity of that orbit is reasonable to operate space telescope.

The distance from the earth is reasonable to communicate.

-short wave moving time for operating instrument or for receiving picture data.

Edited November 29, 2010 by alpha2cen

[D H]

Oops. In post #11 I previously called the Lagrange point directly behind the Sun the Sun-Earth L1 point. (Post is now correct). The Sun-Earth L1 point is between the Sun and the Earth. The point behind the Sun is the Sun-Earth L3 point.

 

Even though getting there would be relatively cheap, there is no reason to put a satellite there. Communications would be a bit difficult. A better option for observing the Sun is the approach taken by NASA with its STEREO satellites. One is in an orbit with a period of 347 days while the other has a period of 387 days. The phase angle between the satellites grows by about 44 degrees per year -- up to February 2011, that is. They will be 180 degrees apart on February 6. The phase angle will then decrease until 2015, when they will be opposite the Sun from the Earth. After that the phase angle will increase again (but by then the satellites will probably be dead).