Posted on 06/09/2006 10:50:42 AM PDT by SunkenCiv
New Scientist for Dec 14, 2002, had a cover story for Planet X:
The Hunt for Planet XJust over a year after the New Horizons' launch, it will... pick up enough velocity to reach Pluto, possibly as early as July 2015... In their new research, Melita and Brunini have explored three possible reasons for the Kuiper Cliff... The third possibility is that the region beyond was brushed clear by the gravity of Planet X... the KBO orbits they have investigated so far fit in best with the influence of a Planet X.
by Heather Couper
and Nigel Henbest
Experts' vote could mean demotion for Pluto
Rocky Mountain News | August 12, 2006 | Jim Erickson
Posted on 08/13/2006 8:58:09 PM EDT by SunkenCiv
http://www.freerepublic.com/focus/chat/1683111/posts
Pluto Could Lose Planet Status
PhysOrg.com | 21 June 2006 | Staff
Posted on 06/22/2006 7:11:12 AM EDT by PatrickHenry
http://www.freerepublic.com/focus/f-news/1653562/posts
Keep on truckin Geoff....
Theory of Periodic Mass ExtinctionsNemesis has not been found, although Richard A. Muller of the University of California at Berkeley continues to track dim red stars to discover if one of them might be a companion to the sun. Also, evidence of impact (such as iridium-rich clay layers or widespread shocked minerals) has not been found in association with all the major extinctions, as would be predicted by the hypothesis. There is excess iridium at the end-Triassic (208 million years ago) and Late Eocene events, as would be expected if impact occurred then, but no such evidence is seen at other events in the periodic series that have been studied in detail. Hence, we have an empirical observation of periodicity but no new hypotheses that suggest interesting tests. This situation is not conducive to scientific effort or to intellectual curiosity, so interest in the question of periodic extinctions has died down. But not completely: there is an interesting scientific paper on the problem published by M. R. Rampino and B. M. Haggerty in Earth, Moon, and Planets (Vol. 72, Nos. 1-3, pages 441-460; 1996), entitled "The 'Shiva Hypothesis': Impacts, Mass Extinctions, and the Galaxy."
Frank R. Ettensohn
quoted by Jason Hanlon
Discovery of a Young Planetary-Mass BinaryWe have identified a companion to the young planetary-mass brown dwarf Oph 162225-240515. This pair forms a resolved binary consisting of two objects with masses comparable to those of extrasolar giant planets. Several lines of evidence confirm the coevality and youth of the two objects, suggesting that they form a physical binary. Models yield masses of 14 and 7 times the mass of Jupiter for the primary and the secondary object, respectively, at an age of 1 million years. A wide (240astronomical unit) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation.
Ray Jayawardhana
and Valentin D. Ivanov
really nice space fantasy art here:
http://www.extrasolar.net/usage.asp
It's the product of the late John Whatmough, an article about whom turned up in the usual extrasolar news search on Google (see below). Must have been alright, he liked Clannad.
World of his own
by Dean Shaloup, Telegraph Staff
Published: Saturday, Sep. 23, 2006
http://www.nashuatelegraph.com/apps/pbcs.dll/article?AID=/20060923/NEWS01/109230087/-1/sports
Harrington and Van Flandern hypothesized an interloper of some sort had disturbed the moon system of Neptune, carrying off one former moon which we now know as Pluto (and nowadays, Charon would have been carried off in the same event). This antedates TVF's "exploding planets" model. If such a deux ex machina event occurred, perhaps it wound up ending its existence in a humungous impact on Uranus, tipping that planet's axis into the ecliptic. :')Why can the major planets have their satellites moving in direct and retrograde orbits as well?Abstract: Now we use the Jacobian integral of circular restricted three-body problem to establish a testing function of the stability of satellites. This method of criterion may be applied to the stability problem of satellites when the six elements of the instantaneous orbit of the satellite with respect to its parent planet are known.
by Wong Chia-ho
Applied Mathematics and Mechanics
Volume 12, Number 4
April, 1991
"By means of an electronic computer, we can find the stable region of a satellite with a quasi-circular orbit. The boundary surface of this region is a nearly oblate ellipsoid. The volume of this enclosed space is much smaller than that of binding by Hill surface and that of sphere of action."
As the expressions of relative kinetic energy of a satellite with respect to its parent planet have the same form for the direct as well as the retrograde orbits, they can coexist in the same region at the same time.Why we have not yet found a retrograde planet in the solar system?Abstract: In this paper we use the Jacobian integral of the circular restricted three-body problem to establish a testing function of a moving testing particle when it moves like a planet. This function determines whether or not the particle will stay in a definite region (which may be called stable region, SR). By means of checking with an electronic computer, we can find that the SR of quasicircular orbit of retrograde planet motion is much less than the SR of direct planet motion. It is the reason why the existence of a retrograde planet is very rare.
by Wong Chia-ho
Applied Mathematics and Mechanics
Volume 11, Number 5
May, 1990
Planet XThe third search for Planet X began in April 1927. No progress was made in 1927-1928. In December 1929 a young farmer's boy and amateur astronomer, Clyde Tombaugh from Kansas, was hired to do the search. Tombaugh started his work in April 1929. On January 23 and 29, Tombaugh exposed the pair of plates on which he found Pluto when examining them on February 18. By then Tombaugh had examined hundreds of plate pairs and millions of stars... Tombaugh continued his search another 13 years, and examined the sky from the north celestial pole to 50 deg. south declination, down to magnitude 16-17, sometimes even 18. Tombaugh examined some 90 million images of some 30 million stars over more than 30,000 square degrees on the sky. He found one new globular cluster, 5 new open star clusters, one new supercluster of 1800 galaxies and several new small galaxy clusters, one new comet, about 775 new asteroids -- but no new planet except Pluto. Tombaugh concluded that no unknown planet brighter than magnitude 16.5 did exist -- only a planet in an almost polar orbit and situated near the south celestial pole could have escaped his detection. He could have picked up a Neptune-sized planet at seven times the distance of Pluto, or a Pluto-sized planet out to 60 a.u.
by Paul Schlyter
The Nine Planets:
Hypothetical Planets
So, farewell planet Earth -- is this the end of the world as we know it?If the IAU criteria are applied in their strictest sense we are left with a paltry quartet -- Mercury, Venus, Saturn and Uranus -- and a need for a new mnemonic... This was brought to my attention by Sky & Telescope magazine, whose editor, Richard Fienberg, finds the planetary pandemonium embarrassing. He has penned a passionate and very funny editorial this month about how "the IAU's definition of 'planet' is scientifically questionable, confusingly worded and of extremely limited applicability". His criticisms are many, but the most eye-catching is the idea that the IAU has defined the Earth out of planetary existence. According to the IAU's General Assembly, which met in Prague this year, a celestial body can be called a planet only if a) it is in orbit around the Sun; b) it is round (in other words, is massive enough to be shaped into a ball by its own gravity); and c) it has cleared the neighbourhood around its own orbit... "Our own world is threatened by . . . a host of other near-Earth asteroids whose paths around the Sun intersect ours. By strict application of the IAU's new rules, this means Earth is no longer a planet either. Ditto for Mars, Jupiter and Neptune, all of which are accompanied in orbit by little asteroids. Ridiculous!" ...to describe the new Pluto-less planetary octet: Many Very Egotistical Malcontents Just Screwed Up Nomenclature... Fienberg declares defiantly that "there are no plans to remove Pluto from our Sun, Moon and Planets pages".
by Anjana Ahuja
November 13, 2006
Anjana Ahuja
More Planets Emerge With Solar System-Like Orbits
National Science Foundation
October 16, 2001
http://www.sciencedaily.com/releases/2001/10/011016070032.htm
"At least two of the recently detected planets have approximately circular orbits. This characteristic is shared by two planets (one of them the size of Jupiter) previously detected by the same team around 47 Ursae Majoris, a star in the Big Dipper constellation, and one around the star Epsilon Reticulum. The majority of the extrasolar planets found to date are in an elongated, or "eccentric," orbit."
Three new worlds found
Source: cbc
Published: 12 Dec 00 Author: staff
Posted on 12/12/2000 09:32:45 PST by RightWhale
http://www.freerepublic.com/forum/a3a36613d4365.htm
Other Earths: Are They Out There ???
Source: space.com
Published: 23 Jan 01 Author: John G. Watson
Posted on 01/23/2001 14:30:11 PST by RightWhale
http://www.freerepublic.com/forum/a3a6e05f34843.htm
|
X-Planets ping list |
|
· join · view topics · view or post blog · bookmark · post new topic · | ||
|
X-Planets ping list | ||
· join · view topics · view or post blog · bookmark · post new topic · | ||
Astrometric Masses of Extrasolar Planets and Brown DwarfsWe propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.
NASA Hubble Space Telescope Daily Report #4307
Tuesday, February 27, 2007
Pluto's 248-year long orbit is less circular - more elliptical or "egg-shaped" - than those of the other planets. Pluto's orbit has an eccentricity of 0.25, which means that Pluto's distance from the Sun is as little as 29.7 AU - temporarily bringing it closer to the Sun than Neptune - and as great as 49.7 AU. -- Credit: JHU/APL
X-Planets ping list | ||
· join · view topics · view or post blog · bookmark · post new topic · | ||
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.