|Image Credit: NASA|
Object 90377 Sedna – a distant transneptunian object known for its extremely elliptical, 11,390-year-old orbit – is currently on its way to the Perihelion (closest approach to the Sun) in 2076. After that, Sedna ‘will return to space. . Are deep and will not return for millennia, making this overview a unique (or ~ 113 once in a lifetime) opportunity to study something far beyond our solar system. There are no SED missions at work yet, but astronomers are starting to plan for the possibility and the ideal launch date for such a mission is fast approaching, with two of the best launch windows coming in 2029 and 2034.
Sedna was discovered in 2003 by Celtic astronomer Mike Brown and his team, and was one of a series of possible dwarf planets (with bodies of similar size, such as Houmiya, McMac and Eris) whose discovery led to the fall of Pluto in 2006. At best we can say from a distance that the biggest thing in the Sedna A asteroid belt is the same as Ceres, but its composition and origin are very different. Its chemical makeup suggests that it may be covered in cold red organic compounds called tholin, found on Pluto and other Kuiper belt objects. Unlike Pluto, it is generally too cold to allow abundant methane to evaporate on its surface and return as ice, although it may soon acquire a nitrogen atmosphere as it approaches the Sun of Sed.
What really sets Sedna apart from other well-known dwarf planet candidates is its enormous orbit, which takes it to the inner edge of the Urt Cloud, the farthest region of the Solar System, where long-term comets remain hidden. There are several competing principles to explain how Sed ended up in this position. Probably the most high-profile theory is the possibility that the yet unknown ninth planet, perhaps ten times the size of Earth, disrupted Sedna’s orbit and turned it and many other objects into a highly expanded orbit. Visiting Sedna may not solve this particular mystery, but it will tell us a lot about the formation of these highly trans-Neptune objects.
|Jupiter (orange), Saturn (yellow), Uranus (green), Neptune (blue) and Pluto (purple) compared to the orbit of the dwarf planet candidate 90377 Sedna (red). Credit: Szczureq / kheider / NASA (Wikimedia Commons).|
In Sedna’s mission plan, the Voyager spacecraft is not a bad place to find inspiration. They famously took advantage of the lucky alignment of the planets to make glorious trips to the outer solar system, stealing energy from Jupiter to gain speed and reach their farther targets. The same gravity aid will be needed to streamline Sedna’s journey. A team of scientists led by Vladislav Zubko of the Space Research Institute of the Russian Academy of Sciences recently modeled a series of possible routes to Sedna, favoring a 2029 launch date as the most feasible option.
By 2029, they had decided to take the spacecraft first to Venus, then back to Earth (twice), before passing Jupiter on the way to Sedna. Prolonged flight will increase the altitude of the spacecraft over Jupiter during gravitational assistance, reducing the time spent in exposure to the harmful radiation of the gas giant.
A 30-year flight plan also means passing through Sedna more slowly, providing more time to collect data on the object. Selecting this option will give the spacecraft a relative speed of 13.70km / s as it passes through Sedna, a speed that New Horizons reached Pluto in 2015.
|90377 Sedna seen by Hubble Space Telescope in 2004. Credit: NASA.|
The second route proposed by the team will include the 2034 launch, and this time the metallic asteroid will provide an additional flyby of 16 cycles.
At the moment, it is not clear whether Sedna’s mission will really reach the launch pad with all the competitive options available to mission organizers in the next decade, but since this is our only chance for the next 11,000 years, the idea is certain. Proper diligence is given.
Note: This article is taken from Universe Today Click here to view the original article
Source: Universe Today