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| At least two unknown planets could exist in our solar system beyond Pluto. Credit: NASA/JPL-Caltech. |
The New Planets in our solar system are the
objects which attract people more than anything in the universe. The science community
is always excited to know about new planet beyond Pluto. Two research papers
published this week show the evidences of two new planets beyond the orbit of
Pluto. These planets are expected to be much heavier than the Earth and orbiting the
sun from such a large distance that their observation with telescope in nearly
impossible. The papers discuss the perturbations in the orbit of objects beyond
Neptune and the usual behaviour of orbits indicates the presence of at least
two new planets in our solar system.
Researchers
at the Complutense University of Madrid and the University of Cambridge have
studied the behaviour of the orbits of Extreme Trans Neptunian Objects also
called ETNO. ETNO include objects like Pluto, Eris, Makemake, Haumea etc. According
to present solar system model, the objects with semi-major axis greater than
150 AU ( AU is the distance between Sun and Earth) and perihelion (closest approach to the Sun) greater than
30 AU are known as Extreme Trans Neptunian objects (ETNO). The inclination of
their orbit should be about 0 degree with respect to the plane of orbit of
planets and the angle of perihelion should be about 0 or 180 degree. The orbits
of these objects should randomly distributed.
The observations of orbits of ETNO are not
according to the above properties, the semi-major axis of many of these objects
is found to be in range of 150 to 525 AU. The orbit of these objects are also not randomly distributed instead they are found in groups.The average inclination is found to
be about 20 degree and the angle of perihelion is about -37 degree which is not even close to 180 degree.
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| This is a photo illustration of the largest known Kuiper Belt objects. Credit: NASA, ESA, and A. Feild (STScI) |
"This excess of objects with
unexpected orbital parameters makes us believe that some invisible forces are
altering the distribution of the orbital elements of the ETNOs, and we consider
that the most probable explanation is that other unknown planets exist beyond
Neptune and Pluto," lead author Carlos de la Fuente Marcos, of the
Complutense University of Madrid,
“The exact number is uncertain, given that
the data that we have is limited, but our calculations suggest that there are
at least two planets, and probably more, within the confines of our solar
system," Carlos de la Fuente Marcos, scientist at the UCM and co-author of
the study, said in a statement.
The research paper published in ‘Monthly
Notices of the Royal Astronomical Society Letters’ also discusses the Kozai
mechanism relative to Jupiter. Kozai mechanism involves the study of perturbation
in orbit of small object due to the gravitational attraction of heavier object
present at farther away position. They have studied the effect of gravitational
attraction of Jupiter on the orbit of comet 96P/Machholz1. The comet has highly
elliptical orbit and will pass the perihelion near the orbit of Mercury in
2017.
They have also looked at newly discovered
dwarf planet called 2012 VP113. This is present in the Oort cloud and never
comes closer than 30 AU. The orbit of this dwarf planet is also supposed to be
under the influence of dark and ice Super-Earth planets heavier than the Earth
by 10 times. The orbit of these planets should be more than 250 AU from the
Sun.
The presence of massive planets at the distance
of 250 AU is not possible according to the present solar system model. The present
solar system model predicts that no planets exist beyond the orbit of Neptune.
If the above hypothesis confirms then it will change the solar system model.
However, the recent discovery by the ALMA
radio telescope of a planet-forming disk more than 100 astronomical units from
the star HL Tauri, which is younger than the Sun and more massive, suggests
that planets can form several hundred astronomical units away from the centre
of the system.
On the other hand, the team recognises that
the analysis is based on a sample with few objects (specifically 13), but they
point out that in the coming months more results are going to be published,
making the sample larger. “If it is confirmed, our results may be truly
revolutionary for astronomy,” says de la Fuente Marcos.
Reference
Carlos de la Fuente Marcos, Raúl de la Fuente Marcos, Sverre J. Aarseth. "Flipping minor bodies: what comet 96P/Machholz 1 can tell us about the orbital evolution of extreme trans-Neptunian objects and the production of near-Earth objects on retrograde orbits". Monthly Notices of the Royal Astronomical Society 446(2):1867-1873, 2015.
C. de la Fuente
Marcos, R. de la Fuente Marcos. " Extreme
trans-Neptunian objects and the Kozai mechanism: signalling the presence of
trans-Plutonian planets? Monthly Notices of the Royal Astronomical
Society Letters 443(1): L59-L63, 2014.