[science] Two large new "planets" found!

[vincent]

A newfound object in our solar system's outskirts may be larger than any known world after Pluto, scientists said today.

It also has a moon.

Designated as 2003 EL61, the main object in the two-body system is 32 percent as massive as Pluto and is estimated to be about 70 percent of Pluto's diameter.

Other news reports that the object could be twice as big as Pluto are false, according to two astronomers who found the object in separate studies and another expert who has analyzed the data.

If the mass is only one-third that of Pluto, then theory holds that it can't be larger than Pluto, according to Brian Marsden of the Minor Planet Center, which serves as a clearinghouse for data on all newfound objects in the solar system.

Marsden, who was not involved in the discovery but has reviewed the data, told SPACE.com that the mass estimate is very firm, within 1 or 2 percent. "I don?t think it is bigger than Pluto," he said.

Where it fits in

This is still a big world, once again raising the prospect that something larger than Pluto might still lurk out there.

Scientists base their size calculations in part on the object's reflectivity. Since they don't know exactly how much the surface brightness of distant objects varies, there is some wiggle room in their size estimates.

A team led by Mike Brown of Caltech has been observing 2003 EL61 for a year but was seeking more data before announcing the discovery. Brown said today it may possibly be larger than Sedna, which has been the largest known world beyond Neptune other than Pluto.

Sedna is between 800 and 1,100 miles in diameter. Pluto is about 1,400 miles across.

Brown figures 2003 EL61 has a diameter of around 930 miles.

Is there any chance it is bigger than Pluto?

"No," Brown said in a telephone interview. "Definitely not."

In fact, Brown's team got the new data they had been waiting for, from the Spitzer Space Telescope, last week. While not fully analyzed, he said the Spitzer observations show "absolutely" that the object is not bigger than Pluto.

Who gets credit?

The object was spotted independently by a group led by Jose-Luis Ortiz of the Sierra Nevada Observatory in Spain. Ortiz' team announced the finding in astronomy circles recently and the finding, including the claim that it might be twice as big as Pluto, was reported by an online news site today.

Ortiz said that based on his team's observations, there was one outlying theory could allow 2003 EL61 to be larger than Pluto, but he does not think it is right.

"I do not think it is larger than Pluto," Ortiz told SPACE.com today.

Brown was surprised last night to learn that Ortiz' group had independently found the object, which only yesterday gained the tag 2003 EL61 from the Minor Planet Center. It was a rare case of one group of astronomers unwittingly scooping another.

Brown said that Ortiz' group rightfully deserves credit for making the discovery.

About that moon

2003 EL61 orbits the Sun on an elliptical path beyond Neptune in a region of space known as the Kuiper Belt. It is significantly inclined to the main plane of the solar system where most of the planets travel. It is one of several objects out there now known to have a satellite.

The moon around 2003 EL61 is small, making up only about 1 percent of the mass of the system, Brown said.

"This satellite is the smallest satellite relative to its primary known in the Kuiper belt," Brown said. "Pluto's satellite, Charon, is about 10 percent of the mass of Pluto.

Marsden, of the Minor Planet Center, said it is surprising the object was not discovered earlier. He said it was probably just barely too faint to be spotted in the sky survey done by Clyde Tombaugh that led to the discovery of Pluto 75 years ago.

Brown's team first spotted 2003 EL61, which had no name at the time, using the Samuel Oschin Telescope at Palomar Observatory on May 6, 2004. They did not realized they had found it until Dec. 28, 2004, after scrutinizing their data in and ongoing effort to find Kuiper Belt Objects.

In a series of three images, the object is seen moving across the sky in relation to relatively fixed background stars.

Ortiz's group initially detected the object in 2003 and spotted it again this year, leading to their announcement yesterday

Source

fred666: In addition to 2003 EL61, a larger "planet" (2003 UB313) has been found:

https://www.neowin.net/forum/index.php?show...ost&p=586295113

Edited July 30, 2005 by fred666

[child998]

So when do we move lol

[Yusuf M. Veteran]

I always knew there were other undiscovered planets in our Solar System. This one may be the first of many more to be discovered.

[Crimson Behelit]

Thanks for the update... I always enjoy meeting our celestial neighbors... I wonder if the new planet is mostly composed of gas.

[vincent]

Thanks for the update... I always enjoy meeting our celestial neighbors... I wonder if the new planet is mostly composed of gas.

586293070[/snapback]

You know, that is a good question, since it is believed taht the Kuiper belt is the remnants of bodies that failed to form into planets from the acretion process created by our sun in order to form our solar system, if it does have an atmosphere its probably a very thin one, and mostly contains ice and/or frozen methane on it's surface. But we won't know for sure, a mission to pluto will be underway in the next few years by 2012

[Boffa Jones Veteran]

That is wicked so the samarians were right? That blows the mind.

[Tungsten T]

BREAKING NEWS: 10th Planet Discovered, Bigger than Pluto

By Robert Roy Britt

Senior Science Writer

posted: 29 July 2005

07:59 pm ET

Astronomers have discovered an object in our solar system that is larger than Pluto. They are calling it the 10th planet, but already that claim is contested.

It is the first time an object so big has been found in our solar system since the discovery of Pluto 75 years ago.

The discovery, announced today by Mike Brown of Caltech, came just hours after another newfound object, one slightly smaller than Pluto, was announced.

The new planet, temporarily named 2003 UB313, is about three times as far from the Sun as is Pluto.

"It's definitely bigger than Pluto," said Brown, who is professor of planetary astronomy. The object could be up to twice as large as Pluto, Brown told reporters in a hastily called NASA-run teleconference Friday evening.

http://space.com/scienceastronomy/050729_new_planet.html

Edited July 30, 2005 by fred666

[matt74441]

Big deal, another large Kuiper belt object. Neat though.

[Tungsten T]

Big deal, another large Kuiper belt object. Neat though.

586295165[/snapback]

bigger than Pluto

[Fred Derf Veteran]

This doesn't prove that we have 10 (or 11) planets, but rather that we have 8.

[Fred Derf Veteran]

Nine's a charm

Dr. Jewitt raises the interesting possibility that Kupier Belt objects might one day be discovered that are even larger than our ninth planet. If that happens, what does it mean for Pluto? Should it be stripped of planetary status and reclassified as a member of the Kuiper Belt? Or should newly discovered "Plutos" be classified as planets as well?

These are difficult questions that await the astronomical community. For now, however, Pluto's status as a planet seems secure. In a press release dated Feb. 3, 1999 the International Astronomical Union stated that "No proposal to change the status of Pluto as the ninth planet in the solar system has been made by any Division, Commission or Working Group of the IAU responsible for solar system science. Lately, a substantial number of smaller objects have been discovered in the outer solar system, beyond Neptune, with orbits and possibly other properties similar to those of Pluto. It has been proposed to assign Pluto a number in a technical catalogue or list of such Trans-Neptunian Objects (TNOs) so that observations and computations concerning these objects can be conveniently collated. This process was explicitly designed to not change Pluto's status as a planet."

Mistaken reports that the IAU intended to strip Pluto of its planetary status caused an uproar among astronomers and in the popular press. It seems that Pluto is a sentimental favorite to remain a planet among both scientists and the public. However, if more trans-Neptunian objects are discovered that are even larger than Pluto, the debate could begin anew.

http://science.nasa.gov/newhome/headlines/ast17feb99_1.htm

[raid517]

BREAKING NEWS: 10th Planet Discovered, Bigger than Pluto

By Robert Roy Britt

Senior Science Writer

posted: 29 July 2005

07:59 pm ET

Astronomers have discovered an object in our solar system that is larger than Pluto. They are calling it the 10th planet, but already that claim is contested.

It is the first time an object so big has been found in our solar system since the discovery of Pluto 75 years ago.

The discovery, announced today by Mike Brown of Caltech, came just hours after another newfound object, one slightly smaller than Pluto, was announced.

The new planet, temporarily named 2003 UB313, is about three times as far from the Sun as is Pluto.

"It's definitely bigger than Pluto," said Brown, who is professor of planetary astronomy. The object could be up to twice as large as Pluto, Brown told reporters in a hastily called NASA-run teleconference Friday evening.

http://space.com/scienceastronomy/050729_new_planet.html

586295113[/snapback]

Things always seem to get bigger than they really are once the press get a hold of them.

[MrStoo]

I just read this on space.com its amazing what we can find now it truly is, their will be a mission to pluto in a some years time, whenever we get there, we might have more information about our solar system with the technology we will have then. Hope there is life lol be nice to make friends with our extraterrestrial neighbours, hope we get more information soon :)

Stu

Btw the live coverage of the spacewalk is on nasa tv if anyone wants to know :)

[Andre]

Now to point Hubble in the direction of the "planet" and get a nice view. :D

[Crimson Behelit]

1) What are the boundaries of our solar system? Growing up I always thought Pluto's trajectory around the sun was, in essence, the boundary of our solar system.

2) I am confused. Why is Pluto's classification as a planet under question? Why exactly are we now unsure that Pluto is a planet with the discovery of these two new planets?

[glassofwater]

1) What are the boundaries of our solar system?  Growing up I always thought Pluto's trajectory around the sun was, in essence, the boundary of our solar system.

2) I am confused.  Why is Pluto's classification as a planet under question?  Why exactly are we now unsure that Pluto is a planet with the discovery of these two new planets?

586298245[/snapback]

You could say the egde of the solar system is where the oort cloud ends or when the solar wind stops.

Pluto is considered by many to be like the larger objects found in recent years to be just a large kuiper belt object.

[Fred Derf Veteran]

1) What are the boundaries of our solar system?  Growing up I always thought Pluto's trajectory around the sun was, in essence, the boundary of our solar system.

2) I am confused.  Why is Pluto's classification as a planet under question?  Why exactly are we now unsure that Pluto is a planet with the discovery of these two new planets?

586298245[/snapback]

1) The actual boundary of the solar system is called the Heliopause: http://www.nationmaster.com/encyclopedia/Heliopause

2) Pluto is just one of many large objects in the Kupier Belt. It has more in common with a comet than it does with a planet. Another former "planet" was declassified so there is some precident. Ceres (between Mars and Jupiter) was once known as a planet. Pluto has only been a planet for 75 years.

As far as I am concerned, we live in a solar system with 8 planets. I'll wait for science to catch up.

[zhangm Supervisor]

Generally, the heliopause is considered the outer boundary of the solar system. It is marked by a bow shock, an area of interaction between the solar wind and interstellar winds.

[vincent]

1) The actual boundary of the solar system is called the Heliopause: http://www.nationmaster.com/encyclopedia/Heliopause

2) Pluto is just one of many large objects in the Kupier Belt. It has more in common with a comet than it does with a planet. Another former "planet" was declassified so there is some precident. Ceres (between Mars and Jupiter) was once known as a planet.  Pluto has only been a planet for 75 years.

As far as I am concerned, we live in a solar system with 8 planets.  I'll wait for science to catch up.

586298376[/snapback]

Here is an interesting article Fred.

Defining 'Planet': Newfound World Forces Action

"The word planet is simply not a scientific word, it is a cultural word."

- Mike Brown, leader of the "10th planet" discovery team

The claim Friday that a 10th planet has been discovered in our solar system has set off a fresh round of debate and international talks aimed at defining the most vexing term in astronomy: the word planet.

A formal proposal could come within a week or two. But some astronomers see no easy resolution.

Now, the guy who stirred the latest dust is trying to snuff the whole debate by repositioning planet as a cultural term that no longer has any scientific meaning.

"Scientists have for the most part not yet realized that the term planet no longer belongs to them," says Caltech's Mike Brown, who led the discovery of the new larger-than-Pluto object.

Brown's new view comes after contemplating six years of mostly fruitless scientific arguments that began when the public became outraged over a rumor that scientists planned to demote Pluto, a rumor rooted in the fact that some astronomers had already stopped calling Pluto a planet by the late 1990s.

"I finally realized the mistake we astronomers had been making all along," Brown told SPACE.com yesterday. "The word planet is simply not a scientific word, it is a cultural word. Once you get over that trap the rest becomes easy."

The problem

At the heart of the problem is small world that should never have been called the ninth planet when it was found 75 years ago.

Pluto is small, its orbit very noncircular, and it travels 17 degrees outside the main plane of the solar system where the other planets roam. In recent years, several other round worlds at least half as big as Pluto have been found on similar offbeat paths, including two announced last week in addition to 2003 UB313, whose orbit is inclined a whopping 45 degrees.

Most astronomers view all of them, Pluto included, as members of the Kuiper Belt

( other terms are used, too, to describe the increasingly complex outer solar system).

The newfound object, temporarily named 2003 UB313, is perhaps 1.5 times the diameter of Pluto and appears to have a similar surface rich in frozen methane. So Brown called it the 10th planet in a hastily arranged teleconference with reporters Friday evening.

NASA, which funded the research, appeared to endorse the label by using Brown's terminology in its official press release.

But yesterday, NASA's Paul Hertz said, "It's not NASA's job to decide what is and what is not a planet." Hertz, chief scientist in the agency's Science Mission Directorate, acknowledged the task falls to the International Astronomical Union (IAU).

"We anticipated there would be a difference of opinions," Hertz said in a telephone interview.

Wildly different, it turns out.

If 2003 UB313 is a planet, one argument goes, then so are those other round things out there. So the new kid on the block would have to go to the back of the line, numerically. It might be No. 12 or No. 24, depending on whose scheme you like.

Proposal soon?

Efforts to craft an official definition have dragged on for years.

The IAU, responsible for nomenclature of all things beyond Earth, has been mulling a planet definition since at least 1999. An IAU Working Group specifically set up to develop a recommendation has been stalled for the past six months.

But most of the dozen members in the group were "exchanging a lot of email this weekend," said Alan Stern of the Southwest Research Institute, who is on the committee.

The members have said they "want to get something done, pronto," Stern told SPACE.com. He said it's possible a proposal could be finalized in a week or two and made public. Still, group members have clearly different ideas in mind.

A synopsis of Stern's thinking:

A planet is a body that directly orbits a star, is large enough to be round because of self gravity, and is not so large that it triggers nuclear fusion in its interior.

"I think there's a consensus moving in this direction," Stern said.

The actual definition will, at least, be more complex than that. Stern favors calling the smaller objects dwarf planets, for example. Other astronomers prefer the term minor planet. Another term bandied about is Kuiper Belt planets. Some don't like the idea of applying the planet label at all.

Let there be 8

Brian Marsden, who is also on the IAU Working Group and who runs the Minor Planet Center where data on objects like these end up, says a simple definition like Stern's makes sense from a theoretical point of view.

If adopted, the wording would bring our solar system's tally of known planets to about two dozen, Marsden said. But practically speaking, Marsden, who expects it will take "somewhat more than a week or two to come up with a policy," prefers another approach.

"The only sensible solution is to accept that the solar system contains the eight planets known a century or so ago," Marsden said via email, "and to add new members only if they are larger than, say, Mars -- or maybe even the Earth."

(Stern and others contend that such large worlds indeed await discovery.)

The discovery of 2003 UB313 presents "the best chance to resolve the problem," Marsden said. "I doubt that all astronomers will be happy with the outcome, but I would hope that what is decided is enough of a compromise that most of them are."

Forget science

Mike Brown yesterday attempted to shift the whole debate away from science.

In Brown's mind -- and he admits to changing it recently -- Pluto is too enshrined in our culture, from place mats to postage stamps, to strip it of planethood.

"Some astronomers have rather desperately attempted to concoct solutions which keep Pluto a planet, but none of these are at all satisfactory, as they also require calling dozens of other objects planets," Brown wrote on his web site this week. "While people are perhaps prepared to go from nine to 10 planets when something previously unknown is discovered, it seems unlikely that many people would be happy if astronomers suddenly said, 'we just decided, in fact, that there are 23 planets, and we decided to let you know right now.'"

Brown's team is taking a stand.

"We declare that the new object, with a size larger than Pluto, is indeed a planet," Brown wrote. "A cultural planet, a historical planet. I will not argue that it is a scientific planet, because there is no good scientific definition which fits our solar system and our culture, and I have decided to let culture win this one."

He advises the public to "ignore the distracting debates" of the scientists.

It seems clear the IAU Working Group plans to ignore Brown, at least insofar as they expect to forge a scientific definition.

Yet no matter what the group comes up with, you can bank on at least one more year of debate. For a definition to be made official, it must be voted on at an IAU General Assembly meeting. The next one is in Prague in August, 2006.

Source

[ev0|]

I don't see why we can't just say, it must be at least as big as or bigger than Pluto to be a planet. What's so hard about that ?

[excalpius]

2) I am confused.  Why is Pluto's classification as a planet under question?  Why exactly are we now unsure that Pluto is a planet with the discovery of these two new planets?

586298245[/snapback]

Because it is so small and far away it should never have been classified as a "planet" in the first place. For sentimental reasons, no one wants to move it back into the asteroid category where it rightfully belongs. There really are only 8 planets and "planetoid" Pluto. :)

[Fred Derf Veteran]

I don't see why we can't just say, it must be at least as big as or bigger than Pluto to be a planet. What's so hard about that ?

586322865[/snapback]

I heard that if Pluto was used as a reference we would now have 24 planets.

If we want to say that it has to be like Pluto but at least as big then we now have 10 planets and it will probably grow from there given time.

The time has come (the walrus said) to decide to keep Pluto as a planet or to compound the problem further by naming more. We cannot keep saying that this solar system has nine planets without being hypocritical so that sentimental number is gone, kaput. We either have to decide that we have eight planets (a number that will probably never grow) or that we have 10-24 planets with more on the way.

I personally think that now is the time to say that we have eight before the problem is compounded.

[IK47]

We have 10 Planets.

That is all.

[Fred Derf Veteran]

We have 10 Planets.

That is all.

586334327[/snapback]

It is entirely likely that we will continue to find orbitting object larger than Pluto. That number will then continue to rise.

[vincent]

There is alot of "dead planets" in the Oort cloud that failed to form as planets through the acretion stage when our solar system was forming.