Please read my blog "Prophecies about Nibiru's October 2013 imminent return" to get a biblical perspective about this topic.
By Leslie Mullen
Astrobiology Magazine
posted: 11 March 2010
08:16 am ET
A dark object may be lurking near our solar system, occasionally kicking comets in our direction.
Nicknamed "Nemesis" or "The Death Star," this undetected object could be a red or brown dwarf star, or an even darker presence several times the mass of Jupiter.
Why do scientists think something could be hidden beyond the edge of our solar system? Originally, Nemesis was suggested as a way to explain a cycle of mass extinctions on Earth.
The paleontologists David Raup and Jack Sepkoski claim that, over the last 250 million years, life on Earth has faced extinction in a 26-million-year cycle. Astronomers proposed comet impacts as a possible cause for these catastrophes.
Our solar system is surrounded by a vast collection of icy bodies called the Oort Cloud. If our Sun were part of a binary system in which two gravitationally-bound stars orbit a common center of mass, this interaction could disturb the Oort Cloud on a periodic basis, sending comets whizzing towards us.
An asteroid impact is famously responsible for the extinction of the dinosaurs 65 million years ago, but large comet impacts may be equally deadly. A comet may have been the cause of the Tunguska event in Russia in 1908. That explosion had about a thousand times the power of the atomic bomb dropped on Hiroshima, and it flattened an estimated 80 million trees over an 830 square mile area.
Why do scientists think something could be hidden beyond the edge of our solar system?
A recently-discovered dwarf planet, named Sedna, has an extra-long and unusual elliptical orbit around the Sun. Sedna is one of the most distant objects yet observed, with an orbit ranging between 76 and 975 AU (where 1 AU is the distance between the Earth and the Sun). Sedna's orbit is estimated to last between 10.5 to 12 thousand years. Sedna's discoverer, Mike Brown of Caltech, noted in a Discover magazine article that Sedna's location doesn't make sense.
"Sedna shouldn't be there," said Brown. "There's no way to put Sedna where it is. It never comes close enough to be affected by the Sun, but it never goes far enough away from the Sun to be affected by other stars."
Perhaps a massive unseen object is responsible for Sedna's mystifying orbit, its gravitational influence keeping Sedna fixed in that far-distant portion of space.
"My surveys have always looked for objects closer and thus moving faster," Brown said to Astrobiology Magazine. "I would have easily overlooked something so distant and slow moving as Nemesis."
John Matese, Emeritus Professor of Physics at the University of Louisiana at Lafayette, suspects Nemesis exists for another reason. The comets in the inner solar system seem to mostly come from the same region of the Oort Cloud, and Matese thinks the gravitational influence of a solar companion is disrupting that part of the cloud, scattering comets in its wake. His calculations suggest Nemesis is between 3 to 5 times the mass of Jupiter, rather than the 13 Jupiter masses or greater that some scientists think is a necessary quality of a brown dwarf. Even at this smaller mass, however, many astronomers would still classify it as a low mass star rather than a planet, since the circumstances of birth for stars and planets differ.
NASA's newest telescope, the Wide-field Infrared Survey Explorer (WISE), may be able to answer the question about Nemesis once and for all.
WISE looks at our universe in the infrared part of the spectrum. Like the Spitzer Space telescope, WISE is hunting for heat. The difference is that WISE has a much wider field of view, and so is able to scan a greater portion of the sky for distant objects.
WISE began scanning the sky on January 14, and NASA recently released the mission's first images. The mission will map the entire sky until October, when the spacecraft's coolant runs out.
Part of the WISE mission is to search for brown dwarfs, and NASA expects it could find one thousand of the dim stellar objects within 25 light years of our solar system.
Davy Kirkpatrick at NASA's Infrared Processing and Analysis Center at Caltech found nothing when he searched for Nemesis using data from the Two Micron All Sky Survey (2MASS). Now Kirkpatrick is part of the WISE science team, ready to search again for any signs of a companion to our Sun.
"I think the possibility that the Sun could harbor a companion of another sort is not a crazy idea," said Kirkpatrick. "There might be a distant object in a more stable, more circular orbit that has gone unnoticed so far."
Ned Wright, professor of astronomy and physics at UCLA and the principle investigator for the WISE mission said that WISE will easily see an object with a mass a few times that of Jupiter and located 25,000 AU away, as suggested by Matese.
We may not have an answer to the Nemesis question until mid-2013. WISE needs to scan the sky twice in order to generate the time-lapsed images astronomers use to detect objects in the outer solar system. The change in location of an object between the time of the first scan and the second tells astronomers about the object's location and orbit.
"I don't suspect we'll have completed the search for candidate objects until mid-2012, and then we may need up to a year of time to complete telescopic follow-up of those objects," said Kirkpatrick.
Source:
http://www.space.com/scienceastronomy/nemesis-comets-earth-am-100311.html