Science

dipsydoodle

(42,239 posts) Sat Mar 8, 2014, 05:40 AM Mar 2014

The hunt for Planet X

Nasa fails to find mysterious giant body believed to have caused mass extinctions on Earth (and they now say it may not exist at all)

It is one of the great mysteries of astronomy - a giant body, believed to lie somewhere beyond the orbit of Pluto,

Dubbed 'Planet X', Nemesis or Tyche, it was believed that this mysterious large planet or small star might periodically pass through outer comets, sending them flying towards Earth and causing mass extinction.

However, researchers today admitted it may not exist after an exhaustive search of hundreds of millions of objects.

'The outer solar system probably does not contain a large gas giant planet, or a small, companion star,' said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University, University Park, Pa., author of a paper in the Astrophysical Journal describing the results.

Read more: http://www.dailymail.co.uk/sciencetech/article-2576009/The-hunt-Planet-X-Nasa-fails-mysterious-giant-body-caused-mass-extinctions-Earth-say-not-exist-all.html#ixzz2vMXzP783

5 replies

= new reply since forum marked as read

Highlight:

The hunt for Planet X (Original Post) dipsydoodle Mar 2014 OP

I think, for one, it's too simplistic an answer. Warren DeMontague Mar 2014 #1

there are scientists who thinks that dinosaurs were just about extinct when the impact ocurred leftyohiolib Mar 2014 #5

"Believed" by whom? Igel Mar 2014 #2

NASA press release, minus the "admitted" BS the Daily Mail inserted: muriel_volestrangler Mar 2014 #3

Dark Matter is the next candidate jakeXT Mar 2014 #4

Warren DeMontague

(80,708 posts)

1. I think, for one, it's too simplistic an answer.

Reply to dipsydoodle (Original post)

Sat Mar 8, 2014, 05:48 AM

Mar 2014

More likely is that different extinctions had different causes. We can be fairly certain the the Chixiclub impact was responsible for the one 65 million yrs ago, for instance. The Permian extinction may have been caused by a mass outbreak of vulcanism, etc.

leftyohiolib

(5,917 posts)

5. there are scientists who thinks that dinosaurs were just about extinct when the impact ocurred

Reply to Warren DeMontague (Reply #1)

Mon Mar 10, 2014, 02:25 PM

Mar 2014

Igel

(35,337 posts)

2. "Believed" by whom?

Reply to dipsydoodle (Original post)

Sat Mar 8, 2014, 12:30 PM

Mar 2014

I thought this was dead and buried quite a while back. Even was forced out of sci-fi stories because of lack of plausibility. (Which can be seen as burying that bar awfully deep in the ground.)

muriel_volestrangler

(101,352 posts)

3. NASA press release, minus the "admitted" BS the Daily Mail inserted:

Reply to Igel (Reply #2)

Sat Mar 8, 2014, 12:43 PM

Mar 2014

Researchers previously had theorized about the existence of this large, but unseen celestial body, suspected to lie somewhere beyond the orbit of Pluto. In addition to "Planet X," the body had garnered other nicknames, including "Nemesis" and "Tyche."
...
Despite the large number of new solar neighbors found by WISE, "Planet X" did not show up. Previous speculations about this hypothesized body stemmed in part from geological studies that suggested a regular timing associated with mass extinctions on Earth. The idea was that a large planet or small star hidden in the farthest reaches of our solar system might periodically sweep through bands of outer comets, sending them flying toward our planet. The Planet X-based mass extinction theories were largely ruled out even prior to the new WISE study.

Other theories based on irregular comet orbits had also postulated a Planet X-type body. The new WISE study now argues against these theories as well.

http://www.jpl.nasa.gov/news/news.php?release=2014-075

jakeXT

(10,575 posts)

4. Dark Matter is the next candidate

Reply to dipsydoodle (Original post)

Sat Mar 8, 2014, 10:09 PM

Mar 2014

Scientists Suggest Dark Matter Played Role in Dinosaurs' Doom

The conventional wisdom is that a cosmic impact caused the extinction of the dinosaurs 65 million years ago — but now two scientists are adding an unconventional twist to the theory: Maybe, they say, dark matter helped.

The hypothesis, set forth in a research paper by Harvard theoretical physicists Lisa Randall and Matthew Reece, blends two of the science world's biggest mysteries: What is behind our planet's waves of mass extinctions? And what is the nature of dark matter, the mysterious stuff that so far has been detected only by virtue of its gravitational effects?

Physicists still haven't figured out what dark matter is, but Randall and Reece suggest that there's a thin, dense disk of the stuff running along the midplane of our Milky Way galaxy. Our solar system traces an up-and-down, wavy motion through that plane as it travels around the galaxy, like a cork bobbing in a lake.

This illustration provides a rough idea about the solar system's up-and-down motion through the galactic plane as it orbits the center of the Milky Way.

http://www.nbcnews.com/science/science-news/scientists-suggest-dark-matter-played-role-dinosaurs-doom-n47486

Reply to this discussion