The mystery of the tenth planet

25.08.2004

25.08.2004


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British astronomers have put forward a new hypothesis slow rotation of Sedna — the proposed tenth planet of the solar system. In their view, was to blame her companion, who is perhaps the darkest cosmic body in the solar system and prinazhdezhit a previously unknown class of cosmic objects.
British scientists have made another step towards uncovering the mystery of Sedna — the most distant known at this time a large cosmic objects in the solar system. According to the magazine New Scientist, scientists calculate, we still have a satellite of Sedna, which is the darkest object orbiting the Sun and belongs to an entirely new class of celestial bodies. A team of astronomers led by Chandra Wickramasinghe of Cardiff University (UK), published its findings in the Journal of The Observatory.
The fact that the planetoid (or a planet — the scientists are still arguing about the status of Sedna) has to be satellite, scientists announced immediately after opening it. The fact that, as established surveillance of Sedna with the Space Telescope Hubble, it moves too slowly — last night there as long as 20 days, but usually the objects of this size (diameter of Sedna is estimated at a maximum of 1700 km) makes a turn for several hours. Then, astronomers thought that the only explanation for this may be a major satellite, the gravitational field which slowed the rotation of its "master." One of the discoverers of Sedna — Michael Brown — was so confident in the existence of a "friend" at the planetoid that he asked to portray him in the first illustration, prepared for the official launching.
However, the images taken by the most powerful space telescopes Hubble and Spitzer, did not confirm this assumption.
Then the researchers decided that perhaps, the satellite of Sedna in the distant past time to slow down its rapid rotation, but later was lost planetoid at a meeting with some other massive body on the outskirts of the solar system. But now they have found a new explanation for this paradox. According to astronomers, the moon in Sedna's still there, but its properties are such that the satellite is seen through the telescope is very difficult.
If this assumption proves to be a satellite of Sedna would be "the darkest object in the solar system."
A clue "invisibility" of the satellite, according to Wickramasinghe, is that it has a very low reflectivity. This is possible if a satellite is not solid but "frozen like smoke", wherein the vacuum is greater than 85% of its volume. According to scientists, the moon could be, for example, who died comet ice from the surface of which has evaporated, leaving only the large accumulation of carbonaceous substances. These objects are able to absorb up to 99% of photons (light particle), which lie in the region of influence. However, to slow down so much rotation of Sedna, this kind of space object must be hundreds of times larger than any known comet. "If the moon at Sedna does exist, it is unknown to us before dark class of celestial objects," — says Vikramansinge.

However, the astronomer Michael Brown of the California Institute of Technology in Pasadena — one of the discoverers of Sedna — skeptical: "I do not believe the discoveries made on the basis of this analysis. Theorists only consider and interpret the numbers. Though I can not say that they are wrong , "- he said.
According to the scientist, everything can be explained much more simply: if Sedna observation through a telescope performed at intervals close to the speed of rotation of the space object, scientists can make a mistake and decide its speed is lower than it actually is. "It's like if you look at the clock every 25 hours and take that was only an hour," — says Brown. In addition, there is a slight chance that each time using a telescope to take pictures of the planet and its satellite is in front of it or behind it. In any case, the hypothesis is necessary to check the researcher: "We're going back to the research with the help of telescopes, adapting them to look for the moon Sedna. If it is, this time we see her."
The existence of Sedna (the official designation — 2003 VB12) was officially launched March 15, 2004. It was the largest space object in the solar system, astronomers discovered in 1930, when Pluto was discovered. So named in honor of her Inuit goddess of the ocean, which created the sea creatures. How do I find astronomers to make a revolution around the Sun, Sedna is required 10,000 years. Moreover, the orbit of the planetoid is strongly elongated and extends so that the distance from it to our star ranges from 76 to 1,000 astronomical units (AU — the average distance between the centers of the Earth and the Sun). For comparison, Pluto's orbit is removed from the sun by an average of 39 AU Its perihelion (closest point to the Sun orbit) Sedna reached in 2075. Sedna's surface is lighter than the objects of the Kuiper belt, and has a distinct red color, it might be the same color as Mars. Due to the large distance from the sun surface temperature must not exceed -240 degrees Celsius.
Now scientists continue to struggle with a history of Sedna appears in the solar system. In their opinion, there are two possible routes. Sedna could get to its current orbit when another star "was" near the sun, which, according to some assumptions, was born in a dense group of stars-to-peer, and later dispersed.According to the second hypothesis, Sedna may have belonged to another star system and was captured by our luminary.
In addition, until now, astronomers are arguing over whether to consider Sedna new (tenth) planet or asteroid yet (planetoid). They doubt about it, and of belonging to the Kuiper belt, which includes a plurality of open to it of such facilities outside of Neptune, including the ninth planet Pluto. Sedna is too far from the Kuiper belt, and perhaps represents the first detected object from a hypothetical halo around the solar system, consisting of a frozen and extremely remote, but the relatively large cosmic bodies — the Oort cloud.

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