what is the radius of the tenth planet?
109794
2003 UB313 is the largest known trans-Neptunian object (TNO) and the most distant known object in the Solar system. It has at least one moon. The object has already been dubbed the tenth planet by the discoverers, NASA, and some media outlets, but it is not yet clear whether it will be widely accepted as a new planet, or whether Pluto will remain classified as a planet.\n...\nThe diameter of 2003 UB313 has only been inferred, not measured directly. The amount of light reflected sets the lower limit for size at 2250 km. The analysis of observations made by the Spitzer space telescope gave only an upper limit of 3,300 km as Spitzer did not detect any heat coming from the object. Newer thermal observations by astrophysicists at the Max Planck Institute for Radio Astronomy (IRAM telescope) have determined the diameter to be in the range 2500-3500 km with a certainty of 68%. [3] The new findings were published in the journal Nature. [4] Initial Hubble Space Telescope observations, taken to measure diameter directly, are still being analysed. Preliminary results revealed by Brown at a public talk at Foothill College in Los Altos Hills, CA suggested that 2003 UB313 has a high albedo of 92% and is nearly identical to Pluto in size (2300-2400 km).[5] However, Brown has now stated that that measurement was wrong, citing that it was a "premilinary estimate." [6]. Brown emphasizes that analysis of the Hubble data is still ongoing, with results expected by the end of February 2006. [7]
617459
Yes there is a tenth planet out there but they haven't named it yet, all we know is that its a kuiper belt object, and larger than pluto
713948
No, the circumference is nearer 24,900 miles at the equator, if by planet you mean Mother Earth.
18543
The relative size of Earth, Jupiter, Sun = 1 : 10 : 100
483118
no there is no 10th planet.\n\nwell scientists argue that pluto is small and should not be called a planet.\n\nso when they discovered Sedna( the 10th planet), it was smaller than pluto and so was considered as a mini planet.
110589
Surprisingly, there is no total agreement about the size of our Solar System. Some say it's defined by the orbit of the outermost planet (used to be Pluto), while others say it's where the Sun's heliosphere ends. Then there's the definition that I personally favor -- the Oort Cloud of comets.\n\nHere's a breakdown of the three major sizes favored:\nPluto orbit - 5,900^6 km\nHeliosphere - 2.2^10 km \nOort Cloud  - 1.5^13 km (1.6 light years)
500795
Over 2 years ago, scientists DID find a 10th planet beyond Pluto, and it's even larger than Pluto. The planet is a typical member of the Kuiper belt, but its sheer size in relation to the nine known planets means that it can only be classified as a planet. Currently about 97 times further from the sun than the Earth, the planet is the farthest-known object in the solar system, and the third brightest of the Kuiper belt objects. \n\nFor images and info, check the NASA web site: http://www.nasa.gov/vision/universe/solarsystem/newplanet-072905.html
437010
its a "sphere" so to speak...so it does have a radius..\n\nthe problem is that since it spins, its a bit wider at the equator..so you need to specify the radius at that location or the polar radius...\n\nmost ppl care about the equatorial radius.\n\nthe Earth's equatorial radius, or semi-major axis, is the distance from its centre to the equator and equals 6,378.135 km (≈3,963.189 mi; ≈3,443.917 nmi).
1183745
Mars is much smaller than Earth.  About 1/2 the diameter (0.53), and 1/10 of the mass (0.107) of the Earth.\n\nHere's a great set of illustrations showing the relative sizes of all the planets, and the sun.\n\nhttp://www.comagz.com/webmagazine/story/proportions_how_small_we_are
153974
A 10th planet has recently been found in our Solar System. It's designation right now is UB313. Check out the following website for more information:\n\nhttp://channels.isp.netscape.com/news/story.jsp?idq=/ff/story/0001/20060201/1301968801.htm&ewp=ewp_news_0106planet&floc=NI-slot1a
354168
the "smart kid" is incorrect about the size of the sun.  It is only 109 times larger than the planet earth.  The Sun's diameter is 864,938 miles (1,391,980 km). This is almost 10 times larger than the planet Jupiter and about 109 times as big as the Earth. The volume of the Sun is 1,299,400 times bigger than the volume of the Earth; about 1,300,000 Earths could fit inside the Sun.
108382
As of right now we don't know sizes of other planets outside our solar system.\n\n But, Jupiter is the largest planet in the Solar System. With an equatorial diameter of 143,884 km, (89,405 miles), it is as wide as more than 11 Earths stacked side by side. The planet also has the shortest period of rotation - Jupiter days last just under ten hours.
147445
Its all relative..usually we use sun as a point of a reference when we talk about relative size of planets which circle it. Pluto is about the same size as mercury.
31095
The 10th planet was discovered last summer.\n\nJuly 29, 2005: "It's definitely bigger than Pluto." So says Dr. Mike Brown of the California Institute of Technology who announced today the discovery of a new planet in the outer solar system.\n\nThe planet, which hasn't been officially named yet, was found by Brown and colleagues using the Samuel Oschin Telescope at Palomar Observatory near San Diego. It is currently about 97 times farther from the sun than Earth, or 97 Astronomical Units (AU). For comparison, Pluto is 40 AU from the sun. \n\nThe planet's temporary name is 2003 UB313. A permanent name has been proposed by the discoverers to the International Astronomical Union, and they are awaiting the decision of this body before announcing the name.
752294
The event horizon of a Black Hole is spherical.\n\nThe circumference is 2 pi times the radius, where the radius here means something rather different than "the distance to the center", since space is so warped.\n\nThe radius is proportional to the mass of the black hole (not the cube root of the mass, as you might at first think).  The radius is about 10 kilometers for the mass of the Sun, so 20 kilometers for twice the mass of the Sun, etc.
478701
Equatorial diameter 6,804.9 km (4228.4 Miles)\n(0.533 Earths)\nPolar diameter 6,754.8 km (4197.2 Miles)\n(0.531 Earths)\nOblateness 0.007 36\nSurface area 1.448×108 km2 (55.907 Million Square Miles)\n(0.284 Earths)\n\n\n"Mars-5-inch-thing" Sure... but in which category of questions are we?
89108
32.675 AU for jupiter's circumference, and 2.406 AU for mercury.  Jupiter is the largest planet in our solar system.