The Manx Comet and Naturalistic Assumptions
Total Page：16
File Type：pdf, Size：1020Kb
JOURNAL OF CREATION 30(3) 2016 || PERSPECTIVES dust it gives off. Yet to solar system In the modern understanding of the The Manx comet scientists it is assumed to be a very Oort theory, there are multiple regions old and ‘unprocessed’ object. that transition into the Oort cloud. and naturalistic Today it is normally possible from From about the orbit of Neptune to assumptions the spectra to distinguish between a distance of approximately 55 AU is an S-type asteroid, an icy comet the region known as the Edgeworth- Kuiper Belt. Then from about 55 AU Wayne Spencer generating a comet tail, and an extinct comet that can no longer create a tail. to perhaps 200 AU is a region called Scientists may take this discovery as the Scattered Disk. The region from n object described variously as a tending to confirm some of the newer about 3,000 AU to roughly 20,000 AU ‘rocky comet’ or a ‘Manx’ comet A models on the formation of our solar is usually called the Inner Oort cloud. was recently reported by an interna- system. The traditional nebula model The Scattered Disk and Inner Oort tional team of researchers working cloud are thought to have objects with under the PANSTARRS program.1,2 for the formation of our solar system orbits that have a range of inclinations. The ‘Manx’ term describes it as being has no planet migration. But newer 3–5 Objects have been actually observed like a cat without a tail. The object models, such as the Nice model and 6,7 in the Kuiper Belt region and a few has been given a comet designation the Grand Tack model, suggest that have been observed that would have of C/2014 S3 (‘S3’ for short). Object Jupiter, Saturn, Uranus, and Neptune orbits taking them into the Scattered S3 was observed at a distance of migrated in the early solar system. In Disk region. The inner part of the 2.1 AU (astronomical units) from these new models, the movement of Scattered Disk represents the edge of the Sun on 22 September 2014. It is Jupiter and Saturn would cause many what can possibly be observed with a rather unusual object in that it has planetesimals and small objects to be present technology. However, fewer an orbit like a long period comet but deflected outward. These new models objects have been observed in the the spectra of the dust emitted by it for the formation of our solar system Kuiper Belt and Scattered Disk than is very much like an S-type asteroid, would say there could be some rocky accepted models suggest.8,10 making it of a silicate composition. objects in the Oort cloud, but the A comet is generally defined as Thus it raises the question of what the traditional nebula model would say being an object that can generate a significance of a rocky object in an that is unlikely. comet tail. But the distinction between orbit like a long period comet is. Comets and asteroids are believed comets and asteroids is not always so Scientists are suggesting that to have formed in the early solar clear. Asteroids can emit a dust tail if more objects similar to S3 are system when many planetesimals and can give off water. Comets may observed, it could help confirm the were present. Accepted theories on have two types of tails, an ion tail and new solar system origins theories that our solar system posit that comets are being debated today by planetary a dust tail. But comets tend to give formed mainly in the outer planets off much more material in their dust scientists. Object C/2014 S3 orbits region (from Jupiter to Neptune).8,9 the Sun in a retrograde direction, tails than asteroids. The observations Asteroids formed mainly in the region with an orbital inclination of 169.3⁰.1 of C/2014 S3 indicate it has a very between Mars and Jupiter, where Its eccentricity is 0.977,1 making the limited dust tail that is like an S-type temperatures were higher. Some of orbit much more elliptical than that of asteroid; it is much less active in its the small objects deflected outward 1 an asteroid. Its perihelion (minimum ‘tail’ than a typical comet. The near- would have enough velocity imparted distance from the Sun) is 2.049 AU infrared spectrum is used for these and its aphelion (maximum distance by Jupiter and Saturn to allow them observations. There have been other from the Sun) is estimated at 178.9 to escape the Sun’s gravity. A small ‘tailless comets’ but the unique thing AU.1 This makes its orbit very much percentage of them could have enough about C/2014 S3 is that its spectrum is like a number of long-period comets. energy to take them to distances of like an S-type asteroid. The paper by The S3 object has an orbital period of a few tens of thousands of AU and Meech et al. (2016), which reported 860.3 years.1 The discoverers of S3 are yet remain in elliptical orbits. These the discovery of C/2014 S3, states arguing that it must be an object that would become Oort cloud objects. At that the first ‘nearly inactive’ object was ‘stored’ in the Oort cloud for most the aphelion of their orbit these objects observed in a long-period comet orbit of the age of the solar system and was move slowly and thus they could be was 1996 PW. Meech et al. goes on to deflected inward relatively recently. ‘captured’ by the Oort cloud and are compare these two objects: So this is essentially an evolutionary thought by many to remain stable “An exploration of the dynamical way of saying that S3 is a young there for possibly millions or billions history of 1996 PW … showed object, because of the nature of the of years. that it was equally probable that 12 PERSPECTIVES || JOURNAL OF CREATION 30(3) 2016 years. For many long-period comets with orbital periods in the hundreds of thousands to millions of years, they would only traverse a small part of their orbit in 6,000 years. Many of the long-period comets are still on their very first trip toward the Sun. This is actually something astronomers would agree on, even if they believe in an old solar system. There is debate among comet researchers on the question of how many of the long-period comets Figure 1. This comet is designated 2011 L4, also known as comet PANSTARRS. The PANSTARRS are ‘new’ and have not yet ever comet is named after the research project which discovered it. PANSTARRS is an acronym for reached their perihelion. ‘Panoramic Survey Telescope and Rapid Response System’. The PANSTARRS telescope sits on An object like C/2014 S3 could top of the Haleakala volcano in Hawaii. The PANSTARRS system does optical astrometry and photometry using a 1.4 Gigapixel array of CCD cameras. It is used to detect many faint objects, only have made about 7 orbits in including Near Earth Objects, asteroids, comets, and Kuiper Belt Objects. PANSTARRS was used to 6,000 years. It is very plausible that detect the C/2014 S3 comet. a rocky object could still be giving off some dust after such a timeframe. 1996 PW was an extinct comet or One paper estimated what it called the Other long-period comets observed an asteroid ejected into the Oort ‘death-rate’ of HTC comets as being may have a more significant tail than cloud during the early evolution 69,000 years.14 This is the time for them S3, but they could be young for the of the solar system. More recently, to become essentially unobservable. same reasons. Some comets disrupt other Manx candidates have been The Jupiter Family Comets would completely when they pass near the discovered. We have observed five have shorter lifetimes (or ‘death-rates’) Sun. But scientists have estimated of them, which also show comet- than this. So the young-age argument that more typically comets can like red colors similar to 1996 PW. for short-period comets is still valid. make anywhere from a few dozen to C/2014 S3 is the first and only The young-age argument creationists hundreds of perihelion passes before Manx candidate to date with an have made from short-period comets they are ‘extinct’. Thus, in a young-age S-type reflectivity spectrum.”1 I believe applies mainly to the Jupiter point of view, there is no need for an Young-age creationists have Family Comets. But object C/2014 S3 object like S3 to be ‘stored’ for billions argued for a young solar system is not a short-period comet. of years in a hypothetical cloud (the from the lifetimes of short-period How then should young-age Oort cloud) that cannot be observed. comets.8,11–13 Today there are generally creationists understand long-period considered to be two classes of short- comets? Comets in orbits with orbital Conclusion period comets, the Jupiter Family periods greater than 200 years are Comets (JFCs), and the Halley Type considered to be ‘long-period’ comets. Solar system scientists often try Comets (HTCs). The JFC comets have There is a wide range of orbital to classify objects and define them orbits of low inclination and they are periods for the long-period comets, according to their origin. Yet no believed to come from Kuiper Belt from 200 years up into the millions human being was able to observe objects, the orbits of which have been of years.