APOD: Farther Along (2011 May 06)

[neufer]

What are the chances of any of these probes traveling from interstellar to intergalactic space?

Escape velocity from the Milky Way ~ 250 km/s.

Or is it more probable that they will be pulled onto the gravitational fields of another star in our galaxy?

The probes will hardly notice the individual gravitational fields of other stars in our galaxy.

[islader2]

In interstellar space, will the probes emit any type of signals--or will alien contact, if any, be a random event?

[iamlucky13]

Wow, thanks for the prospective.

There was an essay in the Wall Street Journal or some similar publication a while back about this sort of thing - how we used to refer to really big numbers as "astronomical."

These days the astronomical numbers are yielding in their impressiveness to economical numbers. To wit:

The inflation adjusted cost of the Apollo program was around $135 billion from I think the period 1963 to 1975.

We currently add that much to our debt - just our debt, not even our entire federal budget - every 5 weeks.

The biggest single project the US ever undertook, the Interstate Highway System, cost an inflation adjusted $425 billion for the originally planned parts. We gave almost twice that much away to companies that couldn't manage their own finances.

Both Voyager missions together had an inflation-adjusted cost around $3 billion and are nearly 34 years along. The debt grows by that much in 18 hours.

The Voyager missions gain 325 million miles from the sun each year. The debt grows 1,420,000 million dollars each year.

Do you think we'll be able to gather enough information that we're looking for in just a flyby? What then, it just keeps going like the Voyager missions?

Yes. They knew how limited the time would be for collecting information and how that would limit the data collected when the mission was first approved. There is a risk that something could go wrong, in which case they would have almost no time to respond, but that's a continuous reality for interplanetary probes. Even those that orbit only have short windows of opportunity to enter orbit, and many past missions have failed that way.

The New Horizons team is trying to reduce the risk by testing everything and rehearsing procedures as much as possible. They did a full dress rehearsal by studying Jupiter when they flew by it a couple years ago, and it went very well.

After it passes Pluto, they hope to find a Kuiper belt object or two lying close enough to its trajectory to study as a bonus mission. They're identifying candidates currently.

[neufer]

In interstellar space, will the probes emit any type of signals--or will alien contact, if any, be a random event?

So long as our civilization remains intact alien's will be aware of Earth long before they are aware of our space craft.

(Note that we, ourselves, no longer possess the capability to play the phonographs on board Voyager.)

[rstevenson]

(Note that we, ourselves, no longer possess the capability to play the phonographs on board Voyager.)

I still have a working record player, though I'd have to do some work on it to get it to play at 16 2/3 rpm, as required.

Rob

[Chris Peterson]

(Note that we, ourselves, no longer possess the capability to play the phonographs on board Voyager.)

We chose a deliberately primitive recording technique in order to suggest a (hopefully) obvious means of recovering the data. It's highly doubtful that any civilization intercepting the recording will have an off-the-shelf record player available, either. But like any competent human engineer, I'd expect a player could be put together out of common parts in a few hours. I've built a few phonographs from scratch, and could certainly do so again. (And of course, phonographs are still readily available right here on Earth, as commercial products.)

[biddie67]

Admittedly I don't have an engineer's mindset, but to me looking at the golden disk, it might be more akin to the cave drawings here on Earth than interpreted as a "reasonable" attempt to communicate by some alien civilization. Frustrating to be sure to all that worked on developing the disk, I can see some child-like alien playing frisbee with it. I hope its fate is not this but what it was intended for in the first place ....

[Chris Peterson]

Admittedly I don't have an engineer's mindset, but to me looking at the golden disk, it might be more akin to the cave drawings here on Earth than interpreted as a "reasonable" attempt to communicate by some alien civilization. Frustrating to be sure to all that worked on developing the disk, I can see some child-like alien playing frisbee with it. I hope its fate is not this but what it was intended for in the first place ....

I think the assumption is reasonable that any civilization that intercepts the Voyager will recognize it as an artifact from an intelligent species, will be capable of analyzing the function of all the components, and will be looking for some sort of effort to communicate. I suspect that all spacefaring, technological civilizations will share many aspects of their thinking processes.

[iamlucky13]

(Note that we, ourselves, no longer possess the capability to play the phonographs on board Voyager.)

We chose a deliberately primitive recording technique in order to suggest a (hopefully) obvious means of recovering the data. It's highly doubtful that any civilization intercepting the recording will have an off-the-shelf record player available, either. But like any competent human engineer, I'd expect a player could be put together out of common parts in a few hours. I've built a few phonographs from scratch, and could certainly do so again. (And of course, phonographs are still readily available right here on Earth, as commercial products.)

A basic phonograph wouldn't really do it. The disc is a mix of images and sound. You'd get some noise mixed in with the recorded sound, but to any alien, the recorded sound would make almost no sense.

However, the cover of the disc has some symbols intended to represent a basic phonograph and the patterns of the data. At first glance, it would be almost completely unintelligible, but the clearly intelligently made origin would beckon for further study, and given that the most important parts are essentially mathematical, it's far from unimaginable that they'd figure it out.

It's incredibly doubtful it would ever be found, but the design of the disc included a rather insightful look at what the basics of language really are. The process of designing it is fascinating in its own right.

[BMAONE23]

If it is found and decoded, it will contain the directions to a planet that contains Aluminum, Copper, Gold, and Uranium. Lets hope these are truely plentiful thruought the universe.

[neufer]

If it is found and decoded, it will contain the directions to a planet that contains Aluminum, Copper, Gold, and Uranium.

Lets hope these are truly plentiful throughout the universe.

Estimated abundances of the chemical elements in the Solar system.

---

<<Hydrogen and helium are most common, from the Big Bang.

The next three elements (Li, Be, B) are rare because they are poorly synthesized in the Big Bang and also in stars.

The two general trends in the remaining stellar-produced elements are:

(1) an alternation of abundance in elements as they have even or odd atomic numbers, and

(2) a general decrease in abundance, as elements become heavier.>>

[owlice]

<<(Alice can perform ... occultations>>

How (unfortunately) true!

[Chris Peterson]

If it is found and decoded, it will contain the directions to a planet that contains Aluminum, Copper, Gold, and Uranium. Lets hope these are truely plentiful thruought the universe.

It is likely that any civilization a bit more advance than ours (as we can expect any finding Voyager to be) will have the ability to manipulate vast amounts of energy, and if you can do that, all elements are abundant.

[bystander]

<<(Alice can perform ... occultations>>

How (unfortunately) true!

So, you are a witch? A practitioner of the occult?

[neufer]

<<(Alice can perform ... occultations>>

How (unfortunately) true!

So, you are a witch?
A practitioner of the occult?

OCCULT, a. [L. occulo; ob and celo, to conceal.]
Hidden from the eye or understanding; invisible; secret; unknown; undiscovered; undetected.

[B]

To all extraterrestrials

Please recover and return to the Earth the explorer space probes inicated when found floating in space. Thank you for your cooperation.

-Voyager 1
-Voyager 2
-Pioneer 10
-Pioneer 11
-New Horizons
-Dawn
-Kepler (ESA)
-Planck (ESA)
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