Solar System : Trans-Neptunian Objects [ TNOs ]

[R-D-A]

Hey Guys

Today we take a look at the unreachable [ for the time building ] objects of our solar system, that are not as recognized as they should, in my opinion.

Those Objects all are beyond Planet Neptune, and are way to far away for any agency, NASA or ESA to send missions. Pluto is the first one to be designated as a TNO along with Charon, its moon.

1 : Trans-Neptunian Planets [ Dwarf Planets ]

Those are planets that orbit the sun, but are too far away, and too small to be considered as planets. Plus, their orbits are Elliptic. I'll start from bigger to smaller.

A) First is Eris and its moon, Dysnomia.


Eris is a frozen world. Its temperatures are something around 24 Kelvin. Which is -249 Celsius degrees [ I dont know the Fahrenheit climax so I cant really give a number ]

It is extremely far away and at its aphelion it can be almost three times as far from the Earth as Pluto is. Its orbital period is around 557 Earth years. Its surface might consist of Condensed Methane and the planet appears grey and it has most likely no atmosphere.

Dysnomia , on the other hand is extremely small. Its diameter is estimated from 100-250 km and it has of course, no atmosphere. It is most likely a very small rock

B ) Then its Pluto and its moons, Charon, Nix and Hydra.

[ Computer Generated pic that looks nice ]

{Wikipedia}
{The Pluto-Charon system is noteworthy for being the largest of the Solar System's few binary systems, defined as those whose barycentre lies above the primary's surface (617 Patroclus is a smaller example). This and the large size of Charon relative to Pluto has led some astronomers to call it a dwarf double planet. The system is also unusual among planetary systems in that each is tidally locked to the other: Charon always presents the same face to Pluto, and Pluto always presents the same face to Charon: from any position on either body, the other is always at the same position in the sky, or always obscured. Because of this, the rotation period of each is equal to the time it takes the entire system to rotate around its common centre of gravity. Just as Pluto revolves on its side relative to the orbital plane, so the Pluto-Charon system does also. In 2007, observations by the Gemini Observatory of patches of ammonia hydrates and water crystals on the surface of Charon suggested the presence of active cryo-geysers. }

Well,much is already known about Pluto. Its a small rocky world, the second largest TNO object and Charon is its moon, which is about 50% the size of Pluto. Pluto's atmosphere consists of a thin envelope of nitrogen, methane, and carbon monoxide gases, which are derived from the ices of these substances on its surface.

Charon is an icy world unseen by the human eye as of yet. There are no pictures of its surface but its estimated that every element on its surface, just like in Pluto is frozen solid.

Nix and Hydra were recently discovered [ 2005 ] and are very small. They are most likely frozen worlds and their observation to determine details is ongoing.

C) Makemake

I literally know nothing of this one so I'll let the experts explain

{Wikipedia}
Makemake, formally designated (136472) Makemake, is the third-largest known dwarf planet in the Solar System and one of the two largest Kuiper belt objects (KBO) in the classical KBO population.[b] Its diameter is roughly three-quarters that of Pluto.[10] Makemake has no known satellites, which makes it unique among the largest KBOs. Its extremely low average temperature, about 30 K (−243.2 °C), means its surface is covered with methane, ethane, and possibly nitrogen ices.

Initially known as 2005 FY9 and later given the minor planet number 136472, it was discovered on March 31, 2005, by a team led by Michael Brown, and announced on July 29, 2005. Its name derives from the Rapanui god Makemake. On June 11, 2008, the International Astronomical Union (IAU) included Makemake in its list of potential candidates to be given "plutoid" status, a term for dwarf planets beyond the orbit of Neptune that would place the object alongside Pluto, Haumea and Eris. Makemake was formally classified as a plutoid in July 2008.

In a letter written to the journal Astronomy and Astrophysics in 2006, Licandro et al. reported the measurements of the visible and near infrared spectrum of Makemake. They used the William Herschel Telescope and Telescopio Nazionale Galileo and showed that the surface of Makemake resembles that of Pluto. Like Pluto, Makemake appears red in the visible spectrum, but significantly less red than the surface of Eris. The near-infrared spectrum is marked by the presence of the broad methane (CH4) absorption bands. The methane is observed also on Pluto and Eris, but its spectral signature is much weaker.

Spectral analysis of Makemake's surface revealed that methane must be present in the form of large grains at least one centimetre in size. In addition large amounts of ethane and tholins may be present as well, most likely created by photolysis of methane by solar radiation. The tholins are probably responsible for the red color of the visible spectrum. Although evidence exists for the presence of nitrogen ice on its surface, at least mixed with other ices, there is nowhere near the same level of nitrogen as on Pluto and Triton, where it composes more than 98 percent of the crust. The relative lack of nitrogen ice suggests that its supply of nitrogen has somehow been depleted over the age of the Solar System.

The far-infrared (24–70 μm) and submillimeter (70–500 μm) photometry performed by Spitzer and Herschel telescopes revealed that the surface of Makemake is not homogeneous. While the majority of it is covered by nitrogen and methane ices, where the albedo ranges from 78 to 90%, there are small patches of dark terrain whose albedo is only 2 to 12%, and which make up 3–7% of the surface.

The presence of methane and possibly nitrogen suggests that Makemake could have a transient atmosphere similar to that of Pluto near its perihelion. Nitrogen, if present, will be the dominant component of it. The existence of an atmosphere also provides a natural explanation for the nitrogen depletion: since the gravity of Makemake is weaker than that of Pluto, Eris and Triton, a large amount of nitrogen was probably lost via atmospheric escape; methane is lighter than nitrogen, but has significantly lower vapor pressure at temperatures prevalent at the surface of Makemake (30–35 K), which hinders its escape; the result of this process is a higher relative abundance of methane.

Makemake has no satellites

D) Haumea


It has two moons Hi'iaka and Namaka. Haumea and its moons are rocky, frozen worlds and have no atmosphere.

2: Important Areas

A) Kupier Belt

The Kupier Belt is an asteroid belt in the outer solar system. It consists of icy particles and not rocks as the Asteroid Belt. Although similar to it, the Kupier Belt is far larger—20 times as wide and 20–200 times as massive.

B) Oort Cloud

Due to my ignorance on this I will again let the experts give the details

{Wikipedia}

The Oort cloud (pronounced /ˈɔrt/ ort, alternatively the Öpik-Oort cloud IPA: [ˈøpik]) is a hypothesized spherical cloud of comets which may lie roughly 50,000 AU, or nearly a light-year, from the Sun. This places the cloud at nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun. The Kuiper belt and scattered disc, the other two reservoirs of trans-Neptunian objects, are less than one thousandth the Oort cloud's distance. The outer extent of the Oort cloud defines the gravitational boundary of our Solar System.

The Oort cloud is thought to comprise two separate regions: a spherical outer Oort cloud and a disc-shaped inner Oort cloud, or Hills cloud. Objects in the Oort cloud are largely composed of ices, such as water, ammonia, and methane. Astronomers believe that the matter comprising the Oort cloud formed closer to the Sun and was scattered far out into space by the gravitational effects of the giant planets early in the Solar System's evolution.

Although no confirmed direct observations of the Oort cloud have been made, astronomers believe that it is the source of all long-period and Halley-type comets entering the inner Solar System and many of the Centaurs and Jupiter-family comets as well. The outer Oort cloud is only loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of passing stars and of the Milky Way Galaxy itself. These forces occasionally dislodge comets from their orbits within the cloud and send them towards the inner Solar System. Based on their orbits, most of the short-period comets may come from the scattered disc, but some may still have originated from the Oort cloud.

Of course there is much more beyond Neptune, however they are not as notable as the aforementioned, so that should be sufficient

SOURCES : Wikipedia for images and important details.
And some personal Knowledge, as always

Thanks for reading,
R-D-A