Five New Neptunian moons

cyclop writes "It's a new time of discoveries in the Solar System. Just when Cassini discovered two news moons on Saturn, old Earth-based astronomy strikes back by revealing five small bodies around Neptune. The faint moons seem to have eccentric and inclined orbits, and to have been captured by Neptune."

Comments

Mission to Neptune

[cephyn]

Planetary scientists would LOVE a galileo/cassini type mission to neptune. The planet and its moons are just bizarre. It has normal looking full sized moons in retrograde orbit - which normally implies captured bodies...but they are usually irregularly shaped. It has goofy looking moons in normal orbits, which would normally imply a body formed with the planet...but those aren't usually irregularly shaped. And the big moon, Triton, is amazing...huge geyser/volcanic-like plumes of frozen black-stuff. There's theories as to what it is, but the underlying mechanisms aren't well understood. An amazing outer planet.

Re:Mission to Neptune

[ToshiroOC]

Prometheus and JIMO first. Prometheus and JIMO are two overarching names for two similar projects - Prometheus specifies the development of nuclear reactors for generating electricity in space for spacecraft. JIMO stands for the Jupiter Icy Moons Orbiter.

This is a huge development in interplanetary science, once they get it all designed - current technology can't begin to approach nuclear levels of power in space. The solar panels on the rovers bring in ~450watt/hr per day (up to 600 in the right orientation), but solar panels just don't give enough electricity once you start getting out away from the sun - Mars is about as far as you can practically go with solar panels. RTGs (radioactive thermal generators) provide power on the order of 1000-2000 watts for the newer ones, and notably less for the older ones - the 30+ year old Voyagers are running off of these, as is Cassini. Nuclear reactors are planned in the 100,000 watt range to begin with, scaling up to ~1,000,000 watts in the forseeable future.

Science, once Prometheus gets off the ground, is no longer going to be centered around minimizing power usage, but maximizing science return. Ion thrusters, which use very little physical fuel but massive amounts of electrical power, become significantly more feasible for very long trips.

And that leads to JIMO - Jupiter Icy Moons Orbiter. Nuclear powered, ion thrusters, all the science you could ask for. Looking at Europa and more.

The only issue is to get Congress to stop cutting 100s of millions out of the Prometheus/JIMO budget - which they did for FY2005.

AFTER all of this, once we have nuclear and ion propulsion down, we can go out to Neptune. Neptune is a much greater challenge because its much further out - you need more efficient thrusters and more power, and you also need much more powerful transmitters to get enough data back to earth.

Re:Mission to Neptune

[Christopher Thomas]

AFTER all of this, once we have nuclear and ion propulsion down, we can go out to Neptune. Neptune is a much greater challenge because its much further out - you need more efficient thrusters and more power, and you also need much more powerful transmitters to get enough data back to earth.

Alternatively, you can just use a bigger radio dish to receive the signals on Earth. The Voyager and Pioneer craft use RTEGs, but can still be heard as long as we're willing to spend the money to listen. It's only becoming a losing prospect now that some of them are reaching heliopause (much farther than Neptune's orbit).

Miniaturization of instruments and electronics allows reduction in both the power and weight budget of the spacecraft without sacrificing much science; IMO it'll be easier to push a small, expensive RTEG-powered ion craft through relevant funding hoops than a larger craft with a pebble-bed reactor or the like. Even though a PBR craft would be as safe to launch as an RTEG craft, RTEG's launch history and the smaller amount of radioactive material makes it an easier sell politically.

In summary, I think we'd be best off running Prometheus and outer solar system projects in parallel, as there's lots of good science that can be done with RTEG-based ion craft, with less trouble politically.

Re:Mission to Neptune

[ToshiroOC]

Bigger radio dishes are in the works, but those aren't built yet - another concern for a later day. As it is, DSN (deep space network) recieve/transmit time on 70m dishes is massively expensive, and making these missions cost efficient is a big deal - so I see this as one of the major areas in which there could be improvement before outer solar missions.

The reactors they are talking about actually aren't PBRs, I believe, but complex rod arrangements that allow reactors to be as inert as several hundred pounds of radioactive material can be until its far away from earth. Even so, your point about political repercussions is absolutely valid - Prometheus could be totally shut down because of these at any time, and I can just imagine hundreds of people showing up at the launch to protest the proliferation of nuclear fission technologies to space.

And I'm not trying to say there is no future for RTG missions - just that Prometheus will be the first time experiements requiring very large amounts of power will be attempted beyond Earth. Surely a simple mission that isn't so monolithically encompassing as JIMO could benefit from the lower costs and political troubles provided by RTGs, but I believe that the future of outer solar system exploration is going to be primarily in Prometheus-type missions.

Prometheus is meant to lead in to manned Martian missions too... so the cut in funding is doubly dubious.

Re:Mission to Neptune

[Dark Lord Seth]

There are rumors out there of a planet that consists for 70% out of water. It's crust is broken up, creating a geologically interesting system. Due to a high-density atmosphere, it has severe variations in temperature... The farther away from the equater, the colder it becomes. However, the same atmosphere retains heat and causes the dark side of the planet to remain nearly the same temperature. The largest bodies of water on the planet are alive, with massive slow moving currents miles underneath the surface and magnetic activity in the atmosphere causese electrical discharges more powerful then mankind has ever been able to create. The core of this planet is made up out of molten metals and projects a gigantic magnetic field around the planet... Etcetera.

Of course, I'm talking about Terra. Sol 3. Our Earth. Just a friendly reminder that practically ANY planet is, in it's own way, amazing. :)

Re:Mission to Neptune

[Anonymous Coward]

Except Earth isn't composed of 70% water.

Re:Mission to Neptune

[R.Caley]

There are rumors out there of a planet that consists for 70% out of water.[...] Of course, I'm talking about Terra. Sol 3. Our Earth.

In a quick calculation from some numbers to hand I make it more like 0.0003%.

Due to a high-density atmosphere, it has severe variations in temperature...

Isn't the variation in temperatiure mostly due to difference in orientation to the sun.

Re:Mission to Neptune

[adeyadey]

There was an interesting article on spacedaily.com (The case against Hubble)
which, although primarily about Hubble, mentioned the fact that NASA rejected a much cheaper mission option for a Europa-only orbiter costing around $1 billion in favour of the $8 billion JIMO mission. You could have 10 or more SEP/RTG missions for the cost of JIMO.. Solar can even be used for getting to Jupiter-Neptune, by swinging in close to the sun first & picking up momentum with SEP or a solar sail.. Just carry enough fuel to enter orbit on arrival, like Cassini..

Something like JIMO will come eventually, but is it worth sacrificing so many possible missions for that one option?

Re:Mission to Neptune

[mcmonkey]

Due to a high-density atmosphere, it has severe variations in temperature...

Actually, due to the amount of liquid water on the surface, Sol3 has very slight variations in temperature. Prevailing currents carry heat from the equatorial regions to the poles.

Retention of heat by large bodies of water and the 'high-density atmosphere also severely reduce the variation in daytime and nighttime surface temperatures. In contrast, temperatures on Mars, with its this atmosphere, vary from about 27 C daytime to -73 C nighttime.

Re:Mission to Neptune

[cephyn]

I agree that all the planets are uniquely fantastic. But many people think "Neptune? bah. just another gas giant. ho hum" -- or they think all moons are like our moon -- pretty much just a boring rock.

From an astronomer

[Pi_0's don't shower]

Ground based astronomy isn't as sexy as space based astronomy, but has one big advantage -- light gathering power. We can build 8-meter (SUBARU and GEMINI), 10-meter (KECK), and in the near future 30 to 50-meter telescopes. The JWST, by comparison, is only 6.5 meters, and that's still 7 years away (at least). It's expensive to get telescopes into orbit, first off, and to send a probe up, well, you only get one look at the system with that! Additionally, launching anything drives the cost up by tens of millions of dollars. Ground based telescopes are easier to service, last virtually forever, and only have the disadvantage of having the atmosphere to fight with. Adaptive optics, and camera technology have significantly advanced in recent years, so that ground based telescopes with adaptive optics have huge advantages over those without it. They haven't caught the space telescopes yet, but the gap is closing. I'm a huge advocate of hubble, chandra and other space-based missions, but what can be accomplished on the ground (such as this) should NOT be overlooked!

Re:From an astronomer

[cephyn]

regardless, even smaller space telescopes can still do some things better than ground based. I'm all for advancing and utilizing BOTH techniques as much as possible. More science == good. 8D

Re:From an astronomer

[Ragnarok21]

Instead of placing telescopes in orbit, we should be putting them on the moon. Low gravity and no atmosphere are a huge plus for building large aperture instruments.

Re:From an astronomer

[Chuck1318]

Instead of placing telescopes in orbit, we should be putting them on the moon. Low gravity and no atmosphere are a huge plus for building large aperture instruments.

At present, any instruments are manufactured on earth, and it takes a lot more to put anything on the moon than in orbit. So anything we could put on the moon would be a lot smaller and less capable than what we could put in orbit. Maybe someday if we had a moon base and actual manufacturing capability on the moon it could be possible. Arthur C. Clarke's novel Earthight was set in a observatory on the moon.

Re:From an astronomer

[ToshiroOC]

Inflatable optics are a huge new field opening up - the idea is you either send up an optical-quality film that you can stretch out into a nice, HUGE, easily-altered-for-adaptive-optics mirror, or alternatively construct one in space (so you don't have to ruggedize it for the high-G-force ride into orbit). Look at BAA03-24 for a quick glance at what the most recent round of funding was aimed at.

Re:From an astronomer

[R.Caley]

Instead of placing telescopes in orbit, we should be putting them on the moon.

Where they can be even harder to service and be at the bottom of a gravity well to make sure lots of micrometeorites get sucked towards them?

Low gravity and no atmosphere are a huge plus for building large aperture instruments.

Isn't that a pretty good description of a location in orbit?

Is it worth it?

[pilybaby]

I'm very interested in what space can tell us about the universe and its rules etc. But I really see research into moons as being a waste of money that could have been better spent feeding and clothing the poorest in the world.

Re:Is it worth it?

[cephyn]

well thats a valid argument, but it has a flaw. the money spent on science is unlikely, if pulled, to feed and clothe the poor. its more likely to be funneled into defense projects.

the other problem with the "money better spent" on feeding the hungry and clothing the poor argument is that its simply impossible to practically do that. there are too many hands the money and food must cross, and corruption is a given. Sure, we must try, but not at the expense of that which furthers other industries. And science isn't the biggest waste of money. What about the millions paid to sports stars? that should be given to the poor. How about the millions you spend on entertainment? surely you could sacrafice a little fun for someone to eat. maybe you should sacrafice all your fun. work hard and only keep what you need to live. not live comfortably, or happily, just live -- donate the rest to the unfortunate. It's a slippery slope. Sadly, feeding and clothing the poor is simply not an easy problem to fix -- diverting funds from science research is surely not the answer.

Re:Is it worth it?

[cyclop]

I just hate that kind of reasoning.

Money spent on science is not wasted. And the less practical is the science, the more I'm sure that money is not wasted.

I work in science (molecular biology), and I don't do it to help people (although I love if my research can help,of course). I do it primarily because I want to understand the Universe. I do it primarily because I think one of the most important, amazing and noble things humankind can do is trying to understand the universe we have the luck to live within. It is at least as noble as helping the poorest. If not noblest, because we will all die (poor or not poor). But knowledge will last.

Re:Is it worth it?

[Marxist Hacker 42]

Do you really think that the rich would allow money not spent on science to go to the poor? There's a real and profitable reason to keep people poor- and a real and profitable reason to gather money up into incredibly large bank accounts under a single person instead of sharing with everybody. Note, I didn't say they were good reasons- but as long as those reasons are allowed to exist, there is NO chance of money being saved from ending projects like this going to the poor. None at all.

Re:Is it worth it?

[pilybaby]

I didn't say stop all funding to science, I refered explicitly to the kind of research this thread talks about. It wont help us understand the universe any more than we already do, it's just a side note to say "moons can behave like this".

Perhaps I'm just odd, but if I were standing in front of dying people and someone said, "hey lets go do some crazy experiment", I would rather stay and try and help.

Re:Is it worth it?

[shobadobs]

So what exactly do you do to help the world's hungry?

Re:Is it worth it?

[Anonymous Coward]

But I really see research into moons as being a waste of money that could have been better spent feeding and clothing the poorest in the world.

Fortunately, we're talking about results from an American satellite and telescopes in Hawai'i and Chile. Since your country contributed nothing to any of this, you can rest easy and stand proud.

Re:Is it worth it?

[Anonymous Coward]

why just give the poor food and clothing, wouldn't it make more since to teach them to do that on there own, by just giving it to them your just teaching them to be dependent on you and you'll be feeding them forever. that does not fix the problem.

Re:Is it worth it?

[fitten]

A lot of the money/food that already is earmarked to feed and clothe the poorest in the world never finds its way to them. In many cases, warlords in places such as Africa take the food/supplies for their own needs before it can be distributed to the needy.

Re:Is it worth it?

[DLR]

Research always pays off. Always. Sometimes it just adds to the amazing amount of negative knowledged we have (i.e. well THAT doesn't work...) but more often than not even failed experiments pay big dividends (both financialy and scientifically) in the long run. Did you know that nylon was a failed experiment? It was poured down the drain 3 times before someone realized what they had. The adhesive on the back of Post-It notes is another failed experiment (i.e. an adhesive that didn't stick permenently), but with this one 3M kept the the info on the books and when somebody had the bright idea for the post it note that adhesive didn't have to be re-invented. I'm sure other examples abound.

Besides, charity is best left in the private sector. I prefer to see charities that are not administered with the compassion of the IRS or the Post Office.

Re:Is it worth it?

[Madcapjack]

But I really see research into moons as being a waste of money that could have been better spent feeding and clothing the poorest in the world.

A worthy sentiment, but incorrect. If, for example, we diverted all funds for NASA and gave that money to the poor of America, their incomes would only be raised by a few hundreds of dollars (i'm giving a guess). Rather than take money away from worthy research, it would be better if all of the super-rich gave all of their surpluss wealth away, and the same with the defense budget, which is overbloated.

Re:Is it worth it?

[Anonymous Coward]

But I really see research into moons as being a waste of money that could have been better spent feeding and clothing the poorest in the world.

So we'll take the $5 billion dollars we spend annually on space exploration (most likely, a gross over-estimation) and distribution it evenly amongst the one billion people in the world who live in poverty and hunger (most likely, a gross under-estimation). So every poor person in the world gets an annual $5 gift courtesy of the US government.

Whoa. Huge dent in the poverty and hunger levels there.

So let's say that $5,000 USD is an acceptable living wage for most of the world. Now you can only help a million people.

Oh, by the way, in 2002 the number of people living in poverty in the US, as defined by the Census Bureau, was 34.6 million people (http://www.census.gov/hhes/income/income02/prs03a sc.html). So dividing that $5 billion amongst just the poor in the United States gives every poor person about $144.50 every year.

Again, whoa, huge dent in poverty and hunger levels. Twelve bucks a month is not going to make a difference in poverty levels.

Re:Is it worth it?

[xigxag]

Money is not the solution to feeding starving peoples. They don't need money, they need food. And there's already more than enough of that to go around. The reason why they don't have that food has very little to do with them not being able to afford it, and very much to do with their own leaders deciding that guns and palaces are a greater priority than food, roads, supplies. Look at China. It went from having some of the worst famines in history to being a net food exporter in just one generation. How? Not by handouts from the West, but by deciding it could no longer allow political ideology to rigidly get in the way commonsense economic policies.

Re:Is it worth it?

[Anonymous Coward]

>waste of money that could have been better spent feeding and clothing the poorest in the world

Sure, send the money to the poorest in the world so that they can live long enough to outbreed your ability to stop their poverty-- and in the meanwhile put scientists out of work, deprive their children of an opportunity to go the best schools, and diminish developed nations' technological advances.

Net change to human misery applying your logic: INCREASED

Thanks for playing!

But would they have thought to look?

[Marxist Hacker 42]

If it wasn't for Casini? After all, who had imagined moons this size before?

Re:But would they have thought to look?

[Chuck1318]

If it wasn't for Casini? After all, who had imagined moons this size before?

Well, yes, Cassini had nothing to do with it. The five newly discovered moons of Neptune are larger than Mars' moons, which were known before space flight. The Galileo probe to Jupiter discovered numerous moons about the size of the ones recently found by the Cassini probe. The moons are being publicly reported now, but they were observed in 2001 to 2003, before Cassini got to Saturn.

Solarquest

[TheSnakeMan]

Dammit, now Solarquest is even more out of date!

Orbiter Game

[vlm]

When will someone add those moons to orbiter?

Orbiter's home page

Where are the Enternainment Moons?

[Bitsy Boffin]

Cassini discovered two news moons on Saturn,

Ah man, we get enough of news already here on Earth, it's all the same wherever you go, it's about time Cassini discovered some Enternainment Moons, that's what I'm talkin' about.