Dołączył: 31 Mar 2011
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|Wysłany: Sob 10:10, 09 Kwi 2011
At the time, about the only point of interest was that the space probe had collected data during the fly-by, and Galileo’s cameras recorded the image of Ida as they passed each other. Six months later the probe downloaded its data to Earth and a tiny, irregularly shaped companion was discovered orbiting Ida. Eventually named Dactyl [link widoczny dla zalogowanych], it was the first satellite of an asteroid discovered.
Asteroid Collisions May Result in Satellite Formation
The Solar System Is More Crowded Than Assumed
Thirty-seven near-Earth asteroids with satellites are now known and two have two satellites each. The vast majority of minor planet satellites are located in the main asteroid belt between Mars and Jupiter and beyond the orbit of Neptune – TNOs [link widoczny dla zalogowanych], or trans-Neptunian objects.
Recently reclassified Pluto is counted among the TNOs along with its three satellites – Charon, Nix, and Hydra. Many objects with satellites occupy the Kuiper Belt far beyond Pluto and may represent a different class of object than what has been called asteroid or planet. Pluto is considered by many scientists to be one of the nearest Kuiper Belt objects rather than a distant planet.
Near Earth Object Observations Have Resulted in Numerous Minor Planet Satellites
The future of astronomy is likely to be filled with startling new discoveries as new technology provides more data than can be quickly analyzed. The list of asteroids with moons is getting longer. Likely, minor planet satellites will not be
The gravitational fields of asteroids are feeble compared to planets, and they are not likely to capture satellites. A more likely explanation is that asteroid satellites are remnants of asteroid collisions that remain within the gravitational field after the impact.
As improved methods of observation and data collection develop, the structure of the Solar System is becoming increasingly complex. Objects of virtually any size are zipping around the sun and around each other. The problem of neatly classifying everything appears problematic to say the least. The controversy created by Pluto’s reclassification will likely be repeated as more is learned about objects too far or too dim to be clearly observed now.
Is Pluto a Planet or What
What Are Dwarf Planets?
As scientists have enhanced their observations of asteroids to find asteroids that pose potential danger to Earth, dozens of asteroids are now known to have satellites. They are formally referred to as minor planet satellites and about 200 are known. The first one discovered with an Earth-based telescope was observed in November, 1998. The Hubble Space Telescope has found about 50 minor planet satellites.
Dactyl is dwarfed by Ida – only about a mile at its widest point. Its discovery confirmed a decades old theory that some asteroids have companions. The large numbers of asteroids located mainly between the orbits of Mars and Jupiter certainly provide numerous candidates for satellites. Indeed, some of the moons of the outer planets are thought to be captured asteroids.
In October, 1989 the space probe Galileo began its long journey to Jupiter. On August 28 [link widoczny dla zalogowanych], 1993 it passed within 1,500 miles of a potato-shaped asteroid with a maximum length of 35 miles. The dim and distant asteroid was Ida – the second asteroid ever encountered by a spacecraft. Although it was not immediately apparent, Ida was quite special.
Some TNOs are larger than the typical asteroid, many having diameters of exceeding 200 miles. One ­– Eris – appears to be larger than Pluto and much more distant. More investigation is needed to understand the nature of the Solar System beyond the orbit of Pluto.
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