Voyager 1

[Rockhem]

Well, voyager 1 is about to reach interstellar space, I can't wait until humans have sent the first object to interstellar space!

I think voyager is the apollo 11 of space probes. Here you can get live info about Voyager.

[Motokid600]

That craft is so far away now that our sun is just another bright star in the sky. Now...New Horizons. That craft reaches Pluto in 2015. After its flyby are we going to insert it into an orbit in the Kuiper belt or is that craft going to zoom straight out like Voyager? Because if that's the case id damn near bet NH beats Voyager to interstellar space.

[Rockhem]

That craft is so far away now that our sun is just another bright star in the sky. Now...New Horizons. That craft reaches Pluto in 2015. After its flyby are we going to insert it into an orbit in the Kuiper belt or is that craft going to zoom straight out like Voyager? Because if that's the case id damn near bet NH beats Voyager to interstellar space.

New horizons will use its IIRC 34 kilograms of fuel to hopefully fly by a kuiper belt object after it's flyby of Pluto. It will never pass Voyager 1 because it is going slower than it because of the less amount of gravity assists it got.

[metaphor]

We aren't really sure where the "edge" of the solar system is, or if there even is one. There are just different zones going out away from the Sun. Voyager 1 already experienced a drastic decrease in the proton flux in August of last year, and a small increase in galactic cosmic rays around the same time. But the magnetic field hasn't shown much change then. So it seems like particle-wise, Voyager 1 is in the interstellar medium, but the magnetic field of the Sun is still more powerful than the galactic magnetic field.

As for where the solar system "ends" and interstellar space begins, that's up to you. It's like the "edge of space". There isn't a clearly defined line. The gravitational pull of the Sun extends out to a light-year or more.

Edited July 16, 2013 by metaphor

[Albert VDS]

They did say that Voyager 1 needs to read drastic changes in all 3 reading.

IIRC:

Detected Solar particles should be (near)zero.

Detected galactic particles should be seeing a huge increase.

A change in the direction of the magnetic field.

You could argue that the first two definitions are met, but those 2 could drop and rise even more.

By the way, where do you read the magnetic field data?

I found this ftp site with data up till today.

[Drunkrobot]

Here is what I don't quite understand-Voyager 1 got it's last gravity assist from Titan during the fly-by through the Saturn(ien?) system. Voyager 2 got further assists from Neptune and... the seventh planet. Shouldn't Voyager 2 be faster?

[Albert VDS]

Voyager 1 had better use of gravity assist.

[Crush]

Well, voyager 1 is about to reach interstellar space

Again?

According to NASA press releases, voyager 1 has "Left the solar system" about a dozen times now.

* When it got past Pluto orbit (outmost known planet at that time)

* When it passed the Heliosphere

* When it passed the Termination Shock

* When it passed the Heliosheat

* When it passed the Heliopause

* passed orbit of Eris (outmost recognized dwarf planet)

* ...and several other arbitrary "ends of the solar system"

And we will again hear news that Voyager "really left the solar system now" when it

* passed the bow shock

* passed orbit of Sedna (outmost trans-neptunian object)

* Left the Kuiper belt

* passed the orbits of long-period comets

* Left the Oort cloud (which will happen in about 30.000 years)

Some of these marks haven't actually been measured yet, so we will likely get multiple news reports about voyager entering and leaving them.

Edited July 16, 2013 by Crush

[Albert VDS]

Isn't it more the case of the media reporting it as "Voyager has left the solar system" then anything else?

[Lexif]

Relevant XKCD comic:

Mousover-Text: "So far Voyager 1 has 'left the Solar System' by passing through the termination shock three times, the heliopause twice, and once each through the heliosheath, heliosphere, heliodrome, auroral discontinuity, Heaviside layer, trans-Neptunian panic zone, magnetogap, US Census Bureau Solar System statistical boundary, Kuiper gauntlet, Oort void, and crystal sphere holding the fixed stars."

http://xkcd.com/1189/

PS: I'm sure the license used by XKCD / Randall allows this kind of post, if not, please remove.

Edited July 16, 2013 by Lexif
license comment, typo

[Crush]

PS: I'm sure the license used by XKCD / Randall allows this kind of post, if not, please remove.

It does allow it, it is licensed CC-BY-NC.

Other arbitrary edges of the solar system:

- When the sun is no longer the brightest star (optionally: in your favorite wavelength)

- When the sun is no longer the dominant gravity source

Edited July 16, 2013 by Crush

[Kilmeister]

Since we're XKCDing (verb)

http://what-if.xkcd.com/38/

Personally, I've think it's extraordinary that humankind has sent something so far. Then you think of it in the grand scale of things and it only further emphasize how small we really are.

[Albert VDS]

Relevant XKCD comic:

*snip*

Mousover-Text: "So far Voyager 1 has 'left the Solar System' by passing through the termination shock three times, the heliopause twice, and once each through the heliosheath, heliosphere, heliodrome, auroral discontinuity, Heaviside layer, trans-Neptunian panic zone, magnetogap, US Census Bureau Solar System statistical boundary, Kuiper gauntlet, Oort void, and crystal sphere holding the fixed stars."

http://xkcd.com/1189/

PS: I'm sure the license used by XKCD / Randall allows this kind of post, if not, please remove.

As the "Explain XKCD" wiki explains:

Voyager 1 is a U.S. space probe launched in 1977 to study the outer reaches of the Solar System and beyond. Popular press has on several occasions announced that it “has left the solar system†at each point when a boundary has been confirmed or a major event has taken place. This underscores the fact that there is no strictly defined and recognizable boundary of the solar system, or at least we haven't found one yet.

http://www.explainxkcd.com/wiki/index.php?title=1189:_Voyager_1

That comic is not about NASA but the press.

[Lexif]

As the "Explain XKCD" wiki explains:

http://www.explainxkcd.com/wiki/index.php?title=1189:_Voyager_1

That comic is not about NASA but the press.

That was my point.

[Albert VDS]

Then at least give a hint to that in your post.

[Lexif]

I might consider it.

[Rockhem]

Well the guys who control voyager say that once they record a shift the magnetic field, to the galactic one, that is when they leave the solar system. About the oort cloud, it is orbiting the solar system.

So once we see the shift, it will leave the solar system offically, the press just misinterprets things, the actual scientists never said voyager left the solar system.

(Cut'em some slack, we are at the edge of the solar system.)

[Lexif]

That is just one possible definition of the "border" of the solar system, though. But why do we need a sharp border? A lot of the influences of our sun are gradually fading out and blur with the influences of neighbouring stars. In my opinion, defining something like "the border of the solar system" are just a PR excercise, designed to get a mention in the media. I mean, analogous to our "stellar neighbourhood", do you think that it makes sense to define a singular border for the influence of one city over a nearby neighbouring city? It only makes sense in the context of a specific question you are trying to answer.

In the same vein, the term "interstellar medium" only makes sense in specific contexts.

Edited July 17, 2013 by Lexif
typo