Why can we detect planets at 1,000+ parsecs but the IISS can only detect them from 1?

[saulweaver]

Apparently NASA and friends can detect planets that are 5,000 or more light years away and can detect planetary atmospheres with the Hubble that are 150 ly away. I have looked at CT (DGP's Grand Survey) and TNE, and they both seem to indicate that the maximum distance at which a a gas giant can be detected is one or two steenking parsecs.

While exploring the frontier, it would be nice to be able to determine if there are gas giants in the system before going there, or if there is some other fuel source (water, belt ice, etc.)

Are Traveller sensors just hopelessly mired in the 1970s, or are there some sensor rules that I am overlooking? What would be a "realistic" (in the Traveller sense) range to detect gas giants and other fuel sources?

 

[mike wightman]

Don't forget that these detection ranges are for ship mounted sensors.
I'm fairly certain that the sensors on the shuttle could detect the Earth and possibly the Moon but not how many gas giants there are in Eta Bootis.
But seriously, Earth based telescopes are massive and even if we assume advances in technology I doubt ship mounted sensors would be capable of the necessary resolution.
Now what a 100t bay mounted EMS sensor would be capable of...

 

[hunter]

I guess you could always carry the equivalent of the Hubble in your cargo bay!

In T20, you can get sensors that will let you 'see' up to 2 parsecs away.

Hunter

 

[TheEngineer]

Hi,

I would consider the things presented in the construction rule sets (CT,MT,TNE..) to be the "standard" stuff for standard situations.
So, if I take a look at MT contruction I will
find a passiv EMS package usable at interstellar
ranges (specified as 2 parsecs...), which will be sufficent for normal space operations (travel, combat, exploration..).

As a referee I see no actual limitations in the rule set for my players to use additional sensor packages or specials (e.g. sensor array drones) in order to achieve longer ranges.
So they can go "there no one has gone before" but not without already having some pretty scans of the region.

Best regards,

Mert

 

[far-trader]

You should keep in mind that the listed range is usually the short range and apply the penalty for going beyond, and also don't forget to apply the target size bonus. For T20 if you use just the maximum numbers on the tables as the absolute DM's then even the minimal model 1 sensor package will have a +10 to "see" anything over a million displacement tons (about 150m diameter) at 2 parsecs, I think that is far better resolution than we currently have.

 

[tjoneslo]

Originally posted by saulweaver:
Are Traveller sensors just hopelessly mired in the 1970s, or are there some sensor rules that I am overlooking? What would be a "realistic" (in the Traveller sense) range to detect gas giants and other fuel sources?

http://traveller.mu.org/house/sensor.rules.html

The Definitive Sensor Rules for Traveller 4th. It not too difficult to convert them to T20. I've written a similar set of rules for T20 following these guidelines.

 

[Anthony]

e some sensor rules that I am overlooking? What would be a "realistic" (in the Traveller sense) range to detect gas giants and other fuel sources?

Ignoring the definitive sensor rules for the moment, the way in which earth-bound telescopes can detect remote gas giants is time consuming, requiring measurements over a period of months or years, and won't detect all planets. Being able to directly spot a gas giant in another system at a range of 1-2 parsecs isn't all that bad for something you can fit on a scout ship.

 

[mad13142000]

But let's remember that the MT 2-Parsec sensor also allows you to determine the first 3 digits of UPP (well, except for the Starport). I doubt Hubble could find out wether or not a world is habitable even if it were around Alpha Centauri - a mear 4 Ly away. (I don't even think it could FIND an Earth type planet...even that close) So yes, Traveller sensors are very good compared to ours....

-MADDog

 

[Zutroi]

Size Matters!

There are fundamental physics that get in the way of seeing fine detail at great distances with small tools. NASA's currently notional planet-hunting missions will use either VERY LARGE optics, or interferometers (a method of using several sets of small optics to act like one huge optic) with baselines of thousands of kilometers.

These are just not the things you can pack into a starships EMS array. Rest assured that IISS Deep Survey ships with the above capability are out there (IMTU) insuring that Intrepid Travellers that 'Boldly Go Where No Man Has Gone Before' do so using Extensive Survey Data.

 

[mad13142000]

Besides...
I'm pretty sure that Project Longbow could see more than 1 parsec...

-MADDog

 

[saulweaver]

Originally posted by MADDog:
But let's remember that the MT 2-Parsec sensor also allows you to determine the first 3 digits of UPP (well, except for the Starport).

That rings a bell MADDog, but I could not find it. Where does that come from?

Didn't FFS2 have some kind of survey sensors, that cost double the price or something? Were there any rules that defined exactly how those were better than standard sensors?

 

[The Hinterworlds Rambler]

I think it also would be helpful to determine what we exactly mean by "Detect". Do we mean just detect if a planet is there, or what sort of planet is there? There is a great difference between the two, what? A large portion of detection of other planets done now is by calculations and observance of indirect effects (visual distortions/gravimetric, etc.) that an orbiting body has on a star. It is more of a mass based prediction. Spectrographic readings can also be made of objects at distance, but this is a far cry from being able to determine and detail a planet's size, hydrographics, and atmosphere from 1+ parsec away, like some ship sensors can. Thats a lot of information, and way ore advanced that anything we got.

Im sure enterprising Referees can make the logical determination that and Increase in cost and use of some ships tonnage could simulate and increased capacity sensor array or palette.

 

[Andrew Boulton]

I'm fairly certain that the sensors on the shuttle could detect the Earth

Well, yeah, you just look out the window and there it is...

There are T4 rules for detecting planets at here

With decent sensors you can detect a gg at up to 1000 parsecs, and planets at up to 50.

 

[kafka47]

Actually, it is fairly established fact, that the Zhodani computers possess psi-empathy, leading one to speculate that they have organic cores.

Interesting enough, although the rules for CT planet detection are very primative. They work on the basis of percieving orbital patterns and calculating the probable orbits based on computer-models, ie. the referee's hand. So it is not that the Scouts are flying in the Dark but their sensors are trying to find other things...

 

[Andrew Boulton]

Actually, it is fairly established fact, that the Zhodani computers possess psi-empathy

Is it? Where's that mentioned?

 

[mike wightman]

In the CT Zhodani module there is an adventure which involves charting unknown space. The system presented allows ships to scan up to 3 parsecs in any direction and the ships computer model provides a bonus to detecting gas giants.
Does this mean Zhodani sensors are better, bigger, or even (scary music, pause for dramatic effect) psionically enhanced?

 

[DElrick]

Originally posted by Sigg Oddra:
In the CT Zhodani module there is an adventure which involves charting unknown space. The system presented allows ships to scan up to 3 parsecs in any direction and the ships computer model provides a bonus to detecting gas giants.
Does this mean Zhodani sensors are better, bigger, or even (scary music, pause for dramatic effect) psionically enhanced?

I was reading that alien module on Monday night...

The Zhodani ship was a large warship (2,000 tons or so if I remember correctly). It probably just had more space for equipment than your average 100 ton scout.

The psionically enhanced sensors were at a static site (on Zhdant, I think) and were being used to scan towards the core, as well as into the future (which was part of the lead-in to the adventure).

I ran that adventure once at Strathclyde uni in Glasgow. We were more suited to short adventures than to long campaigns.

Cheers

David

 

[Father Fletch]

Be careful in your reading of that 'psionic sensor' and allowing Zhodani to actively create and manufacture 'psionic sensors.' IIRC the device in question is a closely held secret of the highest echelons of Zhodani government. It is a remnant Ancient device, that on odd and completely uncontrolled occasions grants visions to a very limited number of people, mostly those with great psionic sensitivity. It is a unique item and has no counterpart in established canon. While YTU may have the Zho lower in tech but higher in PSI balancing the Impies, who are high in tech but low in PSI, the Zhodani use PSI aboard ships mainly through Psionically active switches and controls. Even those would likely be in limited use, considering that the vast majority of spaceship crews would be dead-head proles, and not PSI active Nobles or Intendants. I see them as safety or hidden switches on important controls, like Navigation boards, cipher equipment, ships safes, weapons lockers, command codes for missiles, etc. Not on every hatch, light switch and toilet handle. They are also likely more expensive to manufacture than normal switches, and this would additionally limit them to “upper class” use.
While the excellent Many-Colored land and Metaphysic Rebellion book series by Julian May has neat descriptions of Psionic enhancement tanks and world-shaking powers, it is not well established in Traveller canon. FF&S has alternate rules for Psi Drive systems and sensors, which could be used IYTU.

As always, YMMV