SALT Telescope First Light

carnun writes "On the 1st of September, 5 years after ground breaking, the SALT Telescope released their first light images to the public. Yesterday one of these images was even displayed on NASA's Astronomy Picture of the Day website. The Southern African Large Telescope, built in South Africa, is the largest telescope in the Southern Hemisphere and (depending on how you define it) the equal largest telescope in the world, but built at a budget of only $30 million, about a tenth cheaper than its nearest competitor. The official opening of the telescope is scheduled for the 10th of November, but scientific observations are already a regular occurence. (Disclaimer: I'm the software engineer responsible for the main telescope server.)" Perhaps as an added bonus carnun could even be persuaded to participate heavily in the discussion. Either way, sounds like a cool project to be a part of.

Comments

Impressive Telescope!

[Nerd Systems]

I read some of the details about this, and saw that this telescope can pick up light as small as a candlepower on the moon's surface. That is a pretty impressive light-gathering ability if I have ever seen one... not even the night vision goggles that the military uses has that good of light-gathering. That is a pretty impressive ability to gather light that dim, which is very valuable on a telescope, being able to pick out the faintest of galaxies very far away, as well as seeing the effects that black holes and the like, can have on galaxies in the very distant reaches of space.

It is amazing how good optics are becoming these days... which doesn't just apply to astronomy, bu can also be applied in other areas... areas that can affect all of us one day, and not just for space exploration. So many technologies that have been honed in the space program, have found their way to our use as public citizens. This is a wonderful thing for all of mankind.

Imagine the technologies that are honed with this project being released to the mainstream public down the road... such concepts as more efficient fiber-optics, with light beams being no longer needing fibers to travel across large distances, but simply having a transmitter and receiver on each end, using such optics as this telescope uses, and not being bothered by fiber cuts and the like...

Astronomy is a wonderful hobby, but at the same time, so many things can be contrived from designing technology to see the heavens... which can help out mankind in ways that we have yet to dream of...

As a sidenote, this server seems very slow, so for those trying to check things out, and not able to see anything as a result of the slashdot effect that I am sure is cripping these servers, check back at a later time to see some wonderful images that this telescope has presented to scientists. Astronomy has always been a wonderful hobby and very valuable scientific tool to the science community.

Re:Impressive Telescope!

[Anonymous Coward]

not even the night vision goggles that the military uses has that good of light-gathering

Omg, hand-sized gadget can't gather as much light as a huge complex worth tens of millions. How impressing!

Re:Impressive Telescope!

[LiquidCoooled]

Imagine the technologies that are honed with this project being released to the mainstream public down the road

Paparazzi camera lenses that can snapshot celebrities indiscretions from another continent?

Re:Impressive Telescope!

[CubicleView]

I haven't been able to get to the site so I'm writing this based on my understanding of regular telescopes. Which can gather lots of light mostly because they're huge. You simply cannot get this kind of light gathering ability in a hand held device, they're too small.

Re:Impressive Telescope!

[Myself]

with light beams being no longer needing fibers to travel across large distances

You mean like free-space optics? Baked.

Re:Impressive Telescope!

[Anonymous Coward]

I read some of the details about this, and saw that this telescope can pick up light as small as a candlepower on the moon's surface. That is a pretty impressive light-gathering ability if I have ever seen one... not even the night vision goggles that the military uses has that good of light-gathering.

Would the military night vision equipment be able to see a bulb as dim as G.W.Bush? From what distance?

Re:Impressive Telescope!

[Anonymous Coward]

Impressive Telescope!

Why, thank you. If you like the size, just wait till you see it in action....

Re:Impressive Telescope!

[Anonymous Coward]

with light beams being no longer needing fibers to travel across large distances, but simply having a transmitter and receiver on each end, using such optics as this telescope uses, and not being bothered by fiber cuts and the like...

A telescope is only able to collect a lot of light by having a large collecting area, those recievers would be _large_. I doubt that would ever turn out to be practical. Let alone having to correct for thermal expansion and other sources of misalignment which would force you to have actuators on it, making the thing more complex. (Thus more expensive and prone to failure.) And what if the area you are in starts to get fogged over, or it starts raining?

Re:Impressive Telescope!

[whimdot]

If this thing can pick up the light of a candle burning on the moon's surface, then someone has been lying to us big time.

Re:Impressive Telescope!

[Anonymous Coward]

Finally! All the boobies in the world without leaving the comfort of your own home!

Oh, wait...

Re:Impressive Telescope!

[Anonymous Coward]

Let us be clear about one thing. This project is in no way related to the "space program". However much it has contributed--which it has--this is not one of the contributions. Whereas space-based telescopes and satellites are making huge contributions to astronomy, current space technology is insufficient to put a telescope this awesome and large into space. I think that everyone can agree on this much.

Where I might editorialize is a small critique of the space program: Running manned missions to and from a scientifically pointless facility using outdated space shuttles and other technology is not as beneficial as it could be. We pay an opportunity cost, since we could be spending money currently diverted to the mars/moon/militarize-space programs on real scientific projects. NASA claims that they aren't sacrificing science, but it is nevertheless being strangled through attrition. Just as impressive would be work on global telecommunications, but that too has suffered. I love science fiction but believe that we could get there faster if we focused first on getting the world and basic research up to speed.

Obligatory question about the server

[Inigo Soto]

I'll let carnun guess it :)

Re:Obligatory question about the server

[Soko]

From TFA: (Disclaimer: I'm the software engineer responsible for the main telescope server.)

My guess is that carnun has a very pissed off webserver admin grabbing him by the collar about now.

WebAdmin: W H A T_T H E_F U C K_W E R E_Y O U_T H I K I N G !!!!
carnun: Heh. Sorry 'bout that...
WebAdmin: *produces diamond encrusted LART* AUUUUUGGGGHHHH!!!!
carnun: *SPLUTCH*

Soko

Re:Obligatory question about the server

[AndyFewt]

Seems like its already toast so he will be busy fixing it.

Re:Obligatory question about the server

[Anonymous Coward]

I dunno, they seem pretty savy to me, now they're redirecting to mirrordot.

FL

[Anonymous Coward]

First Light!

SALT server supernovas

[Mathinker]

In other news, an enormous emission of light and radiation is observed from SA as SALT's servers get slashdotted...

Re:SALT server supernovas

[Amadodd]

And in all likelyhood the whole of SA gets slashdotted as well. Seriously - for a South African it is very irresponsible to put up large image files that every nerd wants to see and then link them from Slahdot.

Re:SALT server supernovas

[DigitumDei]

Site seems to be holding up. I guess having some of the slowest international bandwidth in the world helps sometimes.

Though I doubt many people outside of SA are going to be able to access it.

Re:SALT server supernovas

[fbjon]

North Korea has slower. I think they could take a slashdotting with a 486.

I remember when Nixon talked about SALT

[ReformedExCon]

As I recall, even back in the early 1970s, SALT was one of the key planks of Nixon's presidential strategy. I was under the impression that SALT succeeded and was only finally done away with when GWB took office, but to see that it is still working is very cool.

Re:I remember when Nixon talked about SALT

[flubbergust]

Uhm, that was the Strategic Arms Limitation Talks. I guess they perhaps could use this telescope to see if little green men on Mars have nuclear weapons. I dont think it would matter to Bush anyway. USA already declared they will "invade" Mars.

Re:I remember when Nixon talked about SALT

[MaynardJanKeymeulen]

You're either quite funny or extremely stupid.

Re:I remember when Nixon talked about SALT

[Anonymous Coward]

He's a troll, plain and simple. Probably one of the more clever ones to come through here in a long time, though, doesn't lower himself to crapfloods or anything. There's a genuine pattern to misinform in most of what he posts.

Re:I remember when Nixon talked about SALT

[ReformedExCon]

As I seem to be getting this sort of reaction quite a bit lately, I ask you to list those things for which I "misinformed" which was corrected by a commenter in a reply to which I did not respond with acknowledgement of my error.

There is no intent to misinform here. (Maybe in this case to make a little fun at the expense of the story. After all, the site isn't reachable.) Just to provide my opinion and any information I have regarding the topic at hand.

Please, let me know how I have formed a "genuine pattern to misinform". I will see what I can do about avoiding anything that seems like such.

Re:I remember when Nixon talked about SALT

[MaynardJanKeymeulen]

Hey man, I was just joking..
I tought it was quite funny, but otoh you could have been totally serieus, which was even more funny.

Laugh!

Re:I remember when Nixon talked about SALT

[ReformedExCon]

As for the first link, whatever you may have thought, and whatever the moderators may have thought, such is the way things go. I have since closed my PayPal accounts as a result. It seems that there was no problem with the actual account, and that I was very lucky.

The second one just states the obvious. Mac computers have had a very limited role in the "corporate desktop". I ought to have put quotes around that in my original post, I can't think of why I didn't. Most computer systems that sit on people's desks at their office are Windows terminals. Unless, as I mentioned in the post, you belong to certain very specific industries such as media creation (design houses, advertising houses, music or movie production, etc) or academia, you will be hard pressed to find a Macintosh computer anywhere. Maybe your experience is different and you live in a world where Apple computers are so prevalent that trying to walk without tripping over one is a burden. I don't know. I certainly don't live in that world.

I wouldn't be surprised if you're one of the Adequacy-era trolls, still looking for a home.

Well, you've got me at a disadvantage, then. I haven't got the slightest idea what you are talking about.

I don't comment here for your edification. You're free to ignore my posts to your heart's content.

Re:I remember when Nixon talked about SALT

[Anonymous Coward]

Wow, I barely spent 5 seconds skimming your comment and I can already tell that you're a huge loser. I'm terribly sorry for you and your plight of pathos. That aside, has there been set up a 20721 crapflood bunker?

Re:I remember when Nixon talked about SALT

[Anonymous Coward]

A reformed Ex-Con. Hummm. So you are no longer a republican.

Re:I remember when Nixon talked about SALT

[Anonymous Coward]

"I tought it was quite funny..."

I tought I taw a putty tat.

Depending on how we define what?

[Greeger]

It is the equal largest telescope in the world depending on what measurement? Height? Width? Resolution? I don't like it when news stories use those kinds of boasts because they are so vague. For all we know that could mean that the telescope has the same number of people working for them as the other large telescope.

Re:Depending on how we define what?

[Anonymous Coward]

Large telescopes are always compared by the diameter of their main mirror (or what would be the equivalent diameter in case of a more complicated design).

Re:Depending on how we define what?

[gilzreid]

It is based on the diameter of the primary mirror (~10m for SALT). The equal is the prototype which SALT is based on, the HET in Texas (I think). Resolution depends on diameter so it would also have the best resolution, but the Earth's atmosphere tends to distort things too much. This is why the Hubble Space Telescope (which is a mere 2.4M) is so valuable - no atmospheric disturbance.
However, having a giant mirror means that the telescope can observe faint objects in less time than anything in space at the moment, so can take much higher resolution spectra.

The actual telescope can't use the whole mirror at once because of the design. The telescope only moves in azimuth, which saves a huge amount of cost but means that only a small part of the mirror is used at any one time. As the target rotates around the sky the area on the telescope moves across the mirror to allow longer exposures.

SALT also has very high sensitivity to short wavelengths (blue/UV) which is probably the best of any large telescope, or at least close.

Re:Depending on how we define what?

[DrSkwid]

If this is the case, then how could there be any doubt as to which has the largest diameter ?

Re:Depending on how we define what?

[hcdejong]

Traditonally, the diameter of the mirror (10 m in SALT's case) is used for comparison.

Re:Depending on how we define what?

[katana]

Usually comparisons are based on mirror diameters, so SALT is roughly equal to Keck One or Two, the 10m mirrors on Hawaii. But if you're looking for sharpness of image, then you might be more interested in baselines, where interferometry allows configuration of multiple mirrors to achieve sharper images (by cancelling out interference and unwanted signals), such as the VLT in Chile. Baselines at the VLT can reach 200m, which makes the 10m mirror not quite as impressive.

To put it in slashdot-friendly terms, you shouldn't just compare processors based on clock speed, because different processors may be optimized for different purposes. Mirror size is kind of like clock speed.

Re:Depending on how we define what?

[purple_cobra]

...so SALT is roughly equal to Keck One or Two...

And no-one's made any joke about a pair of kecks? I'm grossly disappointed in the level of schoolboy humour at this site.

Re:Depending on how we define what?

[Anonymous Coward]

In order to make SALT (and HET) cheap, there are some compromises in the optical design. One of those is that it can't actually use all of it's mirror at one time. So if you count the full mirror, it's an 11m telescope, but if you restrict it to the part it can actually use, it's a 9.2m. As an 11m it would be the largest, as a 9.2m it is one of the largest. However, another consequence of the optical design which made it cheap is that the resolution/optical quality is very poor, so it's considerably less effective than the size of the mirror would indicate. But, again, given that it is relatively cheap, it is still a very interesting idea.

The real test is whether or not SALT will work better than the telescope it is based on (HET). HET has been quite a disaster, since they can't seem to keep the pieces of the mirror in alignment. As they have tried to fix HET, it has become not nearly as cheap.

Re:Depending on how we define what?

[CK2004PA]

Baselines at the VLT can reach 200m, which makes the 10m mirror not quite as impressive.

How does this nonsense get modded as +5 Insightful ? The main problem with large ground based mirrors, be it the 8m VLT mirror sets, or 10m Keck/SALT, is atmospheric distortion, in particular the cell size of the distortions.

The VLT is supposed to have conquered this very old problem by having computers change the shape of the concave mirrors rapidly to detect the cell size distortion and correct for it. With this, supposdly, the images would show more detail than Hubble. In real life it hasn't quite worked out yet.

Want proof ? Visit the Hubble homepage and the VLT homepage and compare all of their "best images". Not even close and the Hubble is a mesely 2.8m mirror.

When the VLT beats hubble images, as they promised in the late 90's, then come calling me. Until then bugger off.

Re:Depending on how we define what?

[Anonymous Coward]

Because the "nonsense" is an explanation of the different comparisons of ground-based telescopes, which was the issue at hand, not a comparison of image quality between ground-based instruments and space-based instruments, which seems to be your personal issue.

Re:Depending on how we define what?

[Lucractius]

when theres 7 or 8 or even more little mirrors made up in a complicated array called an interferometer that are combined together to form a larger more powerful telescope. it gets quite complicated then.

Slashdotted

[Jarnis]

I wonder if the telescope could see the smoldering ruins of the webserver from the surface of the moon - as the server just got slashdotted off the face of the earth...

1/10th cheaper?

[Anonymous Coward]

Well, i don't think one tenth is _that_ impressive. Are they sure it's not 10 times cheaper or something?

Re:1/10th cheaper?

[Tomfrh]

It's not correct to say "ten times cheaper" either. Once should say "one tenth the price" or something like that.

Re:1/10th cheaper?

[Tomfrh]

"One should" not "Once should"

Re:1/10th cheaper?

[pavium]

That's another interpretation ...

I was wondering if 'one tenth cheaper' meant
a) it cost 10% of the price or
b) it cost 10% less than the price

Coral Cache

[Anonymous Coward]

Running a bit slow. Here is a coral link http://www.salt.ac.za.nyud.net:8090/content/first_ light/

Re:Coral Cache

[silverkniveshotmail.]

that doesn't relly help, because the high-res images aren't cached.

Mirror

[Max von H.]

Check the MirrorDot page, the original server is already smoking...

Cost-saving measures

[mirni]

about a tenth cheaper than its nearest competitor
----

Definition of 'nearest competitor' aside, I'd be very interested to know in what ways savings of such magnitude were realised. Cheap labour shouldn't account for much, here.

-m-

Re:Cost-saving measures

[Anonymous Coward]

A tenth cheaper than its nearest competitor means its nearest competitor cost around $33.33M.

That may not be what the submitter meant, but it is what s/he said.

B

Re:Cost-saving measures

[hcdejong]

Is it really 'a tenth cheaper', i.e. 10% cheaper than its nearest competitor? I somehow get the impression that the submitter meant 'a tenth the cost of its nearest competitor, i.e. 90% cheaper.

Neither seem correct, as Keck cost $ 140M for two telescopes with a similar diameter.

Re:Cost-saving measures

[Tomfrh]

I suspects that the writer doesn't know how to write all that good.

Re:Cost-saving measures

[carnun]

One of the big reasons is that SALT's primary mirror is spherical. This means that each of the segments are of exactly the same design. A parabolic mirror, like that used on most other telescopes you general have to have different design for many of the segments. Downside - spherical mirror bring aberations. Upside - they can be compensated for quite by secondary mirrors.

The SALT primary consists of 91 segments each of which cost $30000, compare this to the estimated cost of having a single 10m primary ~$1 000 000 000.

Cheap (but highly skilled) engineers do help and then the last contributing factor is that the mirror is fixed in elevation - spherical mirrors mean that this the telescope is not limited to fixed elevation though.

Re:Cost-saving measures

[TheGavster]

Apparently they only can move one axis of the telescope, relying on the rotation of the earth (movement of the heavens for creationists) to get the other axis. Apparently you can actually do pretty well with this method, and save buckets of cash.

Re:Cost-saving measures

[wwphx]

They started with the engineering plans for a telescope already in operation and tweaked from there.

(IANA telescope engineer) The Texas telescope that they copied was already operational and probably largely debugged. So they used those engineering plans, adapted them for local requirements, found out what the problems were that the telescope operators had experienced, and engineered in the fixes. That, in and of itself, is not a cost-saving measure, but could account for their rapid ramp-up to First Light.

The fact that they're using adaptive optics and 91 "sub-mirrors" greatly simplifies things. The mirrors have to be re-aluminized on a regular basis (the 3.5 meter that my wife operates is redone every 4-7 years), the smaller size means that they can (and probably do) have a vacuum chamber on-site for this process.

My wife (PhD astronomy/astrophysics) operates a telescope at Apache Point Observatory (APO) and I've gotten to spend tons of time crawling around there taking pictures. It is a one-piece mirror, 3.5 meters and produces really good science.

The telescope itself has some problems. For example, there are only two limit switches to prevent the telescope from moving in an uncontrolled fashion and damaging itself. By comparison, the Sloan Digital Sky Survey 2.5 meter telescope at the same site has either 11 or 22, I don't recall. The 3.5 was designed by physicists who didn't think the telescope could ever go out of bounds, the Sloan by engineers who knew it would.

One MAJOR exception I must take with their announcement is their talking about their scope being the "information age" telescope. They brag about astronomers not having to come on site to operate the telescope and that they can do things aross the internet..

They ain't the first.

Apache Point Observatory (APO) has been doing this for years on the 3.5, I imagine most modern (less than 10-15 or so years old) do this. In APO's case, the astronomer running whatever science program is scheduled that night, has a control program that they run on their computer (Mac, PC, or *nix) that is almost identical to the control program being run by the on-site operator. The remote observer controls the telescope's pointing and controls the instrument for whatever exposures they want to make. The on-site observer monitors the weather in case they have to do a shutdown, changes instruments on the telescope, diagnosis software problems, corrects pointing models (fine-tunes where the telescope is pointing).

The observer can go to the observatory in New Mexico and do everything on site if they want, but most work is done across the internet. Should the link fail for whatever reason, the on-site operator can continue running the science package.

So SALT is not revolutionary in this aspect. In fact, it sounds to me like it's kind of primitive. From what the PDF says, observers submit their observance requests over the internet and the local staff carries them out. Hmmm, how would I implement that? Perhaps through sending an email message?

I hope it's more sophisticated than that, I know the control program for APO is pretty sophisticated and continuing to evolve.

Re:Cost-saving measures

[mbradmoody]

SALT is based on a telescope designed and built for a consortium of universities, led by the University of Texas at Austin and Penn State. The telescope, called the HET, is located on top of Mt. Fowlkes in far West Texas. The cost of the HET without instrumentation was about $16MM.

flame on the moon

[Anonymous Coward]

SALT can detect objects as faint as a candle flame on the moon.

Now, granted I haven't been to the moon myself but I would tend to think a candle flame there would indeed be extremely faint..

Re:flame on the moon

[Anonymous Coward]

So I'm not the only one that wants to see them light a candle on the moon

Re:flame on the moon

[fbjon]

There are two options:

• Send two slashdotters to the moon and mention Iraq. They will be a-flaming.
• Send the webserver to the moon.

OMG... nerdy poetry!.. :)

[Anonymous Coward]

Did you read the nerd factor 10 poetry on the page? For the ones who can not reach the page:


praise poem of the
Southern African Large Telescope

"At the mountain's top I reach up,
I fill my haversack with stars."
- Tatamkhulu Afrika: Nightrider

when the sun sets
we stand in the failing light
stretch our arms,
catch the falling drops.

Medupe & Marang cup our CCD,
save all falling photons,
deepening into a pool of light
whose surface reflects:

stretch marks from the birth of time
hints of gravity's lenses
the pulse of stars
& mating dance of binary suns;

galaxies digitalized - a heaven
captured in butterfly nets of circuitry
red on the readout, disked for storage:
mysteries, solved and sensuous.

Keith Gottschalk


Emphasis added... :)

Re:OMG... nerdy poetry!.. :)

[Anonymous Coward]

So romantic!

Re:OMG... nerdy poetry!.. :)

[Anonymous Coward]

stretch marks from the birth of time

mating dance of binary suns

God. I'm moved. Like a bowel.

Nice Work!! Keep it up!

[v3xt0r]

cheers! =)

Apollo Moon Landings

[Anonymous Coward]

Is SALT powerful enough to see the American flag on the moon?

Re:Apollo Moon Landings

[Floody]

Is SALT powerful enough to see the American flag on the moon?
No, not an actual flag. Maybe a landing site, but it would be difficult and costly to do and the result would likely be dissatisfying to the layperson (and pointless for scientists).

The VLT was considering this a couple of years ago, not sure if they ever went through with it -- probably killed for budgetary reasons. Just because a telescope can pick up a some form of remote point-source light doesn't mean it can actually resolve the point source in terms of what you are thinking (i.e. a "picture").

Besides, what fool would waste time and resources trying to take "nearby" photos of a place we've already been when the telescope can clearly be put to much more useful scientific endeavors?

Re:Apollo Moon Landings

[Anonymous Coward]

Maybe they missed something the first time

Re:Apollo Moon Landings

[Red Flayer]

"Besides, what fool would waste time and resources trying to take "nearby" photos of a place we've already been when the telescope can clearly be put to much more useful scientific endeavors?"

Well, possibly to stimulate public curiosity to garner political support for more publicly funded projects?

In the US, PR stunts are very important to science in terms of getting budget $$. See "NASA" circa 1965-2005. And what a great way for US to garner more support for a Mars invas... um, landing.

Of course, it being a non-USian telescope, perhaps capturing images of the US flag on the moon is not the best way to get public funds for your projects...

OT:The Intarwebs playing up

[dotgain]

I'm in New Zealand, and at the moment, Slashdot and Google are about the only sites that I can access at the moment. I couldn't contact any of the first 6 hosts in something I searched for earlier. I dunno what the hey is going on...

Re:OT:The Intarwebs playing up

[Stephen Samuel]

Slashdot and Google are about the only sites that I can access at the moment.

Oh, my, GOD! We've slassdoted the universe!

You'd think that a software engineer who works for astronomers would know better.....

Slashdot Effect on SALT

[Nerd Systems]

[ben@mail.nerdsystems.com]#traceroute www.salt.ac.za
traceroute to www.salt.ac.za (192.96.109.50), 30 hops max, 38 byte packets
1 192.168.1.1 (192.168.1.1) 0.698 ms 0.887 ms 0.665 ms
2 10.52.128.1 (10.52.128.1) 10.187 ms 9.563 ms 7.850 ms
3 pos5-0.hstntxgra-rtr2.houston.rr.com (24.28.97.213) 9.569 ms 9.916 ms 7.559 ms
4 srp8-0.hstntxtid-rtr2.houston.rr.com (24.28.101.241) 8.333 ms 8.994 ms 8.143 ms
5 pos0-0.hstntxtid-rtr1.texas.rr.com (24.93.34.98) 9.892 ms 8.441 ms 10.023 ms
6 son0-0-3.dllatxl3-rtr1.texas.rr.com (24.93.33.57) 21.196 ms 27.393 ms 32.544 ms
7 te-2-1.car1.Dallas1.Level3.net (4.71.12.17) 19.828 ms 20.283 ms 21.334 ms
8 ae-1-54.bbr2.Dallas1.Level3.net (4.68.122.97) 20.310 ms 20.147 ms 20.256 ms
9 as-1-0.bbr1.Washington1.Level3.net (4.68.128.201) 51.724 ms 144.726 ms 53.050 ms
10 ae-13-51.car3.Washington1.Level3.net (4.68.121.16) 52.553 ms 53.559 ms 4.68.121.144 (4.68.121.144) 53.905 ms
11 telia-level3-ge.Washington1.Level3.net (4.68.127.242) 53.208 ms 52.291 ms 53.896 ms
12 nyk-bb2-pos0-3-0.telia.net (213.248.80.137) 60.166 ms 58.524 ms 58.151 ms
13 nyk-i3-geth2-0.telia.net (213.248.82.150) 57.985 ms 57.630 ms 60.568 ms
14 telekomsa-01531-nyk-i3.c.telia.net (213.248.82.238) 57.721 ms 59.077 ms 60.514 ms
15 wblv-ip-lir-1-pos-6-3.telkom-ipnet.co.za (196.43.9.105) 282.016 ms 283.310 ms 281.114 ms
16 tenet-gen2-int-gw.telkom-ipnet.co.za (196.25.251.150) 285.889 ms 281.912 ms 284.889 ms
17 saao-ct-int-ipnet.uni.net.za (155.232.200.154) 472.798 ms * 638.632 ms
18 * unknown.uni.net.za (155.232.210.5) 682.421 ms 494.832 ms
19 saao-ct-bb-ipnet.uni.net.za (155.232.210.74) 484.095 ms 615.513 ms 698.510 ms
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *
[ben@mail.nerdsystems.com]#

Wow, pretty high latency... looks like this is going over a satellite connection...
I wonder what their pipe is... obviously nowhere near good enough... as here we are bringing them to a crawl in a hurry... I sure hope this is a Linux box running things, as a Windows box is sure to crater as a result of this...
I've had my site slashdotted before, and it never slowed down to this slow... guess that is what happens when you are going over a satellite link?
Anyone know the speed of this link? Just curious...

Re:Slashdot Effect on SALT

[gnomeza]

http://toolbar.netcraft.com/site_report?url=http:/ /www.salt.ac.za

Linux Apache/2.0.52 Fedora

A smoking pile of linux slag or a smoking pile of windows slag - it's still a smoking pile of slag...

Condolences carnun.

So... how long till we see other planets?

[cool_number_9]

I graduated at the Optical Research Group of my university and while I was doing something completely different, a few people were working on nulling interferometry, a technique used to cancel all the light of the star, thereby allowing the light of the surrrounding planets to filtered through. For this to work, you need telescopes at different places. So they actually want to build an array in space or maybe they already did that.

With this high sensitivity of this new telescope, I'm just wondering if an array could be built on earth. Then we can really start looking for nice warm little planets...

Re:So... how long till we see other planets?

[MaynardJanKeymeulen]

You should have paid more attention.
Such telescopes exist.

Re:So... how long till we see other planets?

[iainl]

Stuff that, how long until we see hott girls riding dinosaurs in space with it? This is of vital importance; we can't allow China to get there first!

Re:So... how long till we see other planets?

[nbarriga]

So they actually want to build an array in space

Actually, the cost of building a space telescope is enormous. I think the budget for Hubble was somethink around $US 1 billion , the same as ALMA(http://www.eso.org/projects/alma/) or the VLT(http://www.eso.org/paranal/) even though Hubble is a very small telescope. And since the main problem with surface telescopes( athmosphere's refraction) has been overcome using active optics, i don't think it's necessary to put another space telescope.

Re:So... how long till we see other planets?

[Anonymous Coward]

Hey, what a coincidence, I also did something at the optics group at my university ... krijg nu wat

He Dhiradj, loop niet de hele dag op slashdot te hangen en ga eens werken ofzo ...

Re:So... how long till we see other planets?

[cool_number_9]

I agree... it will be very expensive, however this website about the Darwin mission at ESA suggests that they're seriously assessing the possibility and they're aiming for a launch in 2015.

Re:So... how long till we see other planets?

[cool_number_9]

Hee... onwijze anomieme lafaard.. :P identify yourself!

Re:So... how long till we see other planets?

[Ihlosi]

I think the budget for Hubble was somethink around $US 1 billion ,

How much is that figure expressed in units of "days of war in Iraq" ? And since the main problem with surface telescopes( athmosphere's refraction)

What about atmospheric absorption of certain wavelengths, earth's rotation during long exposure times, light pollution, dust/scattering in the atmosphere, etc ?

Re:So... how long till we see other planets?

[photonic]

mister 'ik zou eigenlijk druk moeten zijn met mijn proefschrift' absolute afstandsmetrology mazzel, B

Re:So... how long till we see other planets?

[BDew]

Except that Adaptive optics only work at the longest wavelengths. Really only in the near-IR. Getting HST-quality resolution from a single telescope in the optical or UV portions of the spectrum is still a long way off.

Re:So... how long till we see other planets?

[Abcd1234]

An excellent point. In addition, the atmosphere greatly limits what's observable by ground-based telescopes due to molecular and aerosol scattering, and molecular band absoption. For example, much of the UV spectrum is unobservable on the Earth thanks to atmospheric scattering and absorption by ozone. In addition, regions of the IR spectrum, where AO can be used, are absorbed by H2O. See here for more details.

Re:So... how long till we see other planets?

[Hegestratos]

And since the main problem with surface telescopes( athmosphere's refraction) has been overcome using active optics, i don't think it's necessary to put another space telescope.

You've obviously never worked with an AO system, but think you can make wild claims about it anyway. So I've never worked with one on a night-time telescope, but I do have one about one floor down from me right now on a solar telescope.

So let me tell you: AO isn't perfect. If the atmosphere is disturbing the image too much, the AO won't even lock. It'll make good images better, but it can't fix terrible images. Even if you have good seeing conditions, the AO won't get the image to the diffraction limit of the telescope. I doubt any ground-based telescope can get anywhere near Hubble quality regularly. Second, you need to correct the atmosphere in real time, like 500 times per second. You can't integrate a couple of hours like you do when observing faint objects. So you'll need a bright object sufficiently close to the faint object you're observing. Third, the AO can only correct a part of the image, because the atmosphere isn't distorting the image the same way everywhere. If the object you're observing is too large, the AO can't correct the whole image. Fourth, the atmosphere distorts different colors differently. Since typically you want to observe at different wavelengths (i.e., colors), you'll only get one sharp one. Finally, there's no clouds in space.

In short: AO helps when it's not cloudy, the seeing is reasonable to good, you have a bright object close to your target, your target is not too large, and you only want data at one wavelength. There are plenty of valid scientific reasons to want to have space telescopes. Observing at wavelengths that don't get through the atmosphere is just one.

Re:So... how long till we see other planets?

[MrScience]

cool number 9 is correct, NASA is working on these types of projects.

The idea is to build smaller telescopes, or hypertelescopes, and link them together using interferometry (defined).

Re:So... how long till we see other planets?

[sdfad1]

Interesting. Care to tell more about this solar telescope? What's the specs for your deformable mirror? What "guide-star" do you use for wavefront sensing (presumably features on the sun itself)? And what wavefront sensor is it? What wavelength? I'm particularly keen on wavefront sensors cause that's what I'm simulating at the moment (no, can't quite get them all to work yet).

Oh oh, and here's a side question: Is it true that the sun is really not that intense on a "flux per arc second^2" basis? That is, stars are pin-point bright objects, but the sun is bright also because it occupies a larger field of view? No?

Just a few silly questions, sorry, few free to ignore if you're busy.

Southern Sky

[RocketRainbow]

Mmm... we're looking at the same stars.

I love my Southern sky. As an Australian, I can't say "I love a sunburnt country", but I love the Magellanic Clouds, the Southern Cross, the Pliades... Looking up is how I know I'm home.

And of course your photos won't show bizarre things like the upside-down-moon!

It's about darn time people started putting more effort into the southern sky. You can just survey for a night and show up interesting things down here!

Re:Southern Sky

[Anonymous Coward]

I come from a land downunder... where women blow, and men chunder...

Re:Southern Sky

[Anonymous Coward]

Pleiades perhaps?
They're more northern than southern hemisphere.
Omega Centauri would be a more appropriate example of southern majesty.

This telescope

[frinkacheese]

Will pick up a pimple on an astronauts ass..

Re:This telescope

[Anonymous Coward]

Oh, astronauts ride donkeys now?!

Mandatory question

[jurt1235]

Does this also help with my horoscope?

South Africa: South African South Africa Telescope

[Anonymous Coward]

[ South Africa ]
Posted by ScuttleMonkey on 10:07 7th September, 2005
from the man-we-don't-hear-about-this-place-often-enough dept.
A South African writes "On the 1st of September, 5 years after ground breaking South Africanism, the South African Telescope released their first South African light images to the South Africa public. Yesterday one of these South African images was even displayed on NASA's Southern Africa Picture of the Day website. The Southern African Large Telescope, built in South Africa, is the largest telescope in South Africa and (depending on how you define it) the equal largest telescope in South Africa, but built at a budget of only 30 million South African $, about a tenth cheaper than its nearest South African competitor. The official opening of the South African telescope is scheduled for the 10th of November South Africa time, but South African scientific observations are already a regular occurence. (Disclaimer: I'm the South African software engineer responsible for the main South African South Africa telescope server, in South Africa.)" Perhaps as an added South Africa bonus South African carnun could even be persuaded to participate heavily in the South African discussion. Either way, sounds like a cool South African project to be a part of when you're in South Africa.

Obligatory 2001 quote...

[srl100]

"My god, it's full of sta...@~0-tw$%^&e" Hmmm, server must be down.

Re:Australia Still Has Some Pride

[Anonymous Coward]

Goes to show how humour gets lost in the translation. There's a running joke in Australia that an Australian saying "biggest in the southern hemisphere" really means "biggest outside of South Africa".

Then there's also the double entendre of the "banana republic" comments made by a certain Australian treasurer, and their recent revival.

Bronson Bodies

[GomezAdams]

This is great news for astronomy. I just hope they keep an eye out for the Bronson Bodies with their new toy.

Re:Bronson Bodies

[qualico]

I'd mod this funny, but can't comment and mod.

Here is a link in case someone missed the jive.
http://en.wikipedia.org/wiki/When_Worlds_Collide

SALT Telescope?

[commodoresloat]

Did they pay for it after getting money from the Automatic ATM Machine? After typing in their PIN Number? I know, I should RTFA the article before posting. I'll STFU up now.

Re:SALT Telescope?

[Ravatar]

STFU up?

*confused

Re:SALT Telescope?

[Paul Crowley]

Oh, search the STFW!

Re:SALT Telescope?

[Enigma_Man]

You seem to be suffering from RAS syndrome.

-Jesse

You bastards!

[eugene_roux]

We have a tough enough time getting decent bandwidth down here at the Southern tip of Africa, without you bastards Slashdotting our Telescope and taking our undersea cables with it!

Mutter, mutter, mutter...

Or maybe...

[Poromenos1]

Because there was no moon landing! And the Mars rovers look pretty fake to me, too!

Pfft.

[general_re]

Perhaps as an added bonus carnun could even be persuaded to participate heavily in the discussion.

Yeah, right. After that electric-universe clusterfuck yesterday, why would anyone remotely affiliated with legitimate, mainstream science want to come within a mile of this place? And even if someone did - I'm guessing this submission's been in the queue for a bit - do we have time to fit it in, in between our daily doses of kookery?

Hey, on the plus side, I now know for sure that not subscribing was absolutely, 100% the right decision, so it's not a total loss, I guess.

MOD PARENT UP

[aussie_a]

Aha! I was wondering what that meant. I thought it meant it was the largest telescope in the southern hemisphere (depending on how you define the southern hemisphere). I was going to make a post asking how there could be ambiguity over the definition of the southern hemisphere. So thankyou for clearing that up.

Cheap telescope

[photonic]

The nice thing about this telescope is that the whole design is aimed at keeping it cheap. To start with it is almost a direct copy of the Hobby-Eberly telescope, so go there if SALT is slashdotted. Reusing a design of course saves a lot and there will not be a lot of redundant science since HET is located at the northern hemisphere and SALT at the southern. The project has a lot of international partners, but obviously the South African astronomy community is the big winner here.

Then the design of the telescope, this is very uncommon to keep costs down: First of all the telescope cannot cover the whole sky, it has a fixed elevation (something like 40 degrees?) and can only rotate around its vertical axis. This saves of course a lot of mechanics and has as an added benefit that the structure will have a constant sagging due to gravity. The cost you pay is of course a limited view of the sky, but there is plenty to see in the part that is visible.

The second innovation is that the shape of the mirror is not parabolic, as in most telescopes, but spherical. This has two benefits: first, all the mirror segments can be produced with the same curvature, which is cheaper than custom segments as for Keck. Secondly, you can change the elevation of your telescope (over a limited range) without moving the main mirror by rotating the rest of the optics from a point in the center of the sphere (this is possible because of spherical symmetry of the mirror). The downside of the spherical optics is that the optical aberations of the system are more severe than for a parabolic mirror, so you need to add some extra optics to compensate. This is no big problem since HET and SALT are not built for making nice pictures, but primarily for spectroscopy, for which a big light collecting area is more important than the best possible imaging system.

Re:Cheap telescope

[wortelslaai3434]

University of Wisconsin did the design on the only "scientific" instrument on the telescope, the PFIS... or "Prime Focus Imaging Spectrograph". Have a look at http://www.sal.wisc.edu/~ebb/pfis/pics/ for some construction pics and http://www.astro.wisc.edu/salt/ for minimal info.

Re:Cheap telescope

[IceFoot]

"...the telescope cannot cover the whole sky, it has a fixed elevation (something like 40 degrees?) and can only rotate around its vertical axis."

What? They can't crank it down to the horizon and peek in bedroom windows in the next county? Sheesh. :P

Re:Australia Still Has Some Pride

[aug24]

Did you mean banana or bandana?

Either way, I'm impressed!

J.

Re:No even the goggles...!

[BJZQ8]

Tube-type first-gen NV was invented by the Germans in WW2. Americans fielded a rudimentary type for a sniper rifle, but it was cumbersome and not useful.

If you pick it...

[Anonymous Coward]

...it'll never heal.

Salties

[HermanAB]

Yeah, there are many meanings to SALT:

In South Africa, a Saltie is an Englishman - since he is standing with one foot in London, the other in Cape Town and his dong in the salt water...

In Australia, a Saltie is a seawater crocodile.

The combination of the two would be very amusing to watch...

Re:Salties

[StrawberryFrog]

Or a "soutpiel" in Afrikaans. (As a Capetonain living in London, I resemble that remark)

Submitted by a Masochist?

[mulhall]

"...(Disclaimer: I'm the software engineer responsible for the main telescope server.)"

Okay, so unlikely to be responsible for the web server too, but surely professionalism or general comradeship would warn againt submitting your servers to a Slashdotting...

Translation please.

[alex_guy_CA]

What does this sentence from TFA mean? (especially the second half of the sentence)

"the best frames produced by SALT and SALTICAM show star images as small as 1 arcsecond (1/3600 degree), despite being taken when the seeing was 0.9-1.0 arcseconds"

Re:Translation please.

[Xolotl]

Seeing is a measure of the blurring of the images of stars due to movement of air in the atmosphere above the telescope. If you think of the blurring as a gaussian filter applied to the image, then the number quoted is the width of the gaussian (bell) curve at half its height - so the actual size of the blurred image would be rather larger as the gaussian curve flares out at the bottom.

Which means that (thanks to adaptive optics) they've managed to achieve images of stars which are perhaps 2-3 times sharper than the atmospheric effects at the site would normally allow.

Re:Translation please.

[spanklin]

seeing is a measurement of how the atmosphere is degrading the images of stars. So if the seeing is 1.0 arcseconds, this means that after the light from the star passes through the atmosphere, its full-width at half-maximum (FWHM) intensity has an angular size of 1.0 arcseconds. Telescopes and the domes that they are mounted in usually cause the seeing to get worse, so even though the atmosphere is only blurring the image of a star to an angular size of 1.0 arcsecond, when the image is recorded in a camera, it might appear to have a FWHM of 1.2 or 1.5 arcseconds. This effect is sometimes called "dome seeing". What they are claiming is that they did such a good job on the optics and the design of the dome that the dome contributes negligibly to the seeing and that it is performing optimally. My guess is that the reason for this statement is that the HET (the telescope SALT was modeled after) is well known to have issues with bad dome seeing.

Re:Australia Still Has Some Pride

[Anonymous Coward]

Think I've figured out a key difference between British/AU humour and American humour, in a general sense.

British/AU will make a double entendre where the obvious meaning is self promoting, but the less obvious meaning will be self depreciating, or vice versa.

Americans will make a double entendre where both meanings are self promoting. This is possibly why Americans are stereotyped as having the subtly of a sledge hammer, and often don't get British/AU humour.

404 errors, Here is a better link:

[qualico]

Getting 404 errors on the main page when trying to view the images?
Alternatively, they can be viewed here:

http://www.saao.ac.za/news/salt_light.html

Using, my Celestron 9.25" last night here in the north, sure gives you an appreciation of these images and what bigger light buckets nets you.

Showed my wife M57, (Ring Nebula), for the first time.
Albiet, it was washed and faint, its a worthy experience to see things with your "God's Eye".

Can anyone here, who has toured a large telescope, comment on how the captured images compare to the live views?

Re:No even the goggles...!

[Guysmiley777]

No, the Germans (and later Amercians) in WWII had active IR night vision. An IR spotlight illuminated objects and a device (an EO tube) displayed a visible light version of the IR lit scene. This was great... unless the bad guys had a scope, because if they could also see in IR, you looked like a moron with a spotlight and a sign that said "Shoot Me!".

"First gen" NV should refer to the image intensifier family of NVDs, the first of which was the "starlight scope" fielded by the US in Vietnam. These function by amplifing ambient light (hence "starlight") and did not require additional illumination. Unless it was cloudy and moonless, then you were boned.

The Orb

[Anonymous Coward]

I still prefer The Orb's track "S.A.L.T." over this. History:
http://www.thei.aust.com/isite/orb2.html

Re:Australia Still Has Some Pride

[Anonymous Coward]

Stuff a duck, you learn something new everyday
The big pineapple is Australia's number one tourist attraction! http://www.bigpineapple.com.au/info.html

It must be true cause they says right there on their web page.....

a light candle on the moon

[lems1]

from the article: SALT can detect objects as faint as a candle flame on the moon.

If we can look that closer to the moon, why hasn't anybody just taken photographs of the US flag left at the moon during the Apollo missions? That should at least satisfy some of the skeptics out there. Of course, people will then say that the flags were planted using other methods or that the pictures were altered... ah, the human brain...

Re:a light candle on the moon

[The Master Control P]

We can also detect distant stars, even though they are far, far smaller than the angular resolution of any telescope. A candle flame on the moon would cover such a small angle that it would appear as a diffraction-limited dot.

Re:a light candle on the moon

[lems1]

cool. Any way to actually take a picture of that US flag planted on the moon?

I'm dying to see that with my own telescope, but, i could trust a big project like this one or anybody else that NOT NASA.

Re:Australia Still Has Some Pride

[Anonymous Coward]

Then there is the third meaning: that the typical Australian voter (and hence politician) would be more interested in a big banana rather than a big telescope. Hence Australia's dismal research funding and ignorance of the valiant attempts of its research community to avert banana republic status.

SALT, ALMA, ... what's next?

[GodGell]

are these acronmys designed to really mean something? i mean, if you understand what i'm writing then i guess you also know what the word "salt" is, and you probably also know that "alma" means "apple" in Hungarian. what's next? :)

Re:SALT, ALMA, ... what's next?

[nbarriga]

that "alma" means "apple" in Hungarian

Actually i think ALMA was chosen because it means "soul" in spanish.

Re:SALT, ALMA, ... what's next?

[GodGell]

it's even better then.. were they aiming for "apple soul" or something? :)