Supermassive Black Holes --"Did They Form Inside Galaxies or Create Them?"
Giant Elliptical Galaxy Hosts Colossal Black Hole --"Could Swallow Our Solar System Whole" (Weekend Feature)

Rogue Planets of the Milky Way --Astronomers Ask if They Can Sustain Life




Recent disvoveries suggest that the Milky Way hosts nomad planets adrift in space that may play a dynamic role in the universe. Titled "Nomads of the Galaxy," a recent study proposed an upper limit to the number of nomad planets that might exist in the galaxy: 100,000 for every star. And because the Milky Way is estimated to have 200 to 400 billion stars, that could put the number of nomad planets in the quadrillions.

If this proposal is correct, it could be that nomad planets play a dynamic role in the universe. In particular, if life can exist without the warmth of a nearby sun, it raises the possibility that, along with sustaining life, nomad planets could be transporting it as well. While just an idea, it's one that becomes more intriguing when considering not only the number of nomad planets, but the behavior of galaxies.

"In the 20th century, many eminent scientists have entertained the speculation that life propagated either in a directed, random or malicious way throughout the galaxy," said Roger D. Blandford, A co-author of the recent study and director of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University and the SLAC National Accelerator Laboratory.

"One thing that I think modern astronomy might add to that is clear evidence that many galaxies collide and spray material out into intergalactic space. So life can propagate between galaxies too, in principle."

I'm really curious about the exchange of planets between solar systems," said Louis E. Strigari, lead author of the study and research associate at KIPAC and the SLAC, " How often does it happen, and how far can a nomad planet travel? How many trips around our galaxy does it make? I think these are brand new, basic questions. And I think that's an exciting place to be."

"If you imagine the Earth as it is today becoming a nomad planet... life on Earth is not going to cease," said Dimitar D. Sasselov, Professor of Astronomy at Harvard University and the Harvard-Smithsonian Center for Astrophysics, and the Director of the Harvard Origins of Life Initiative. "That we know. It's not even speculation at this point. ...[Scientists] already have identified a large number of microbes and even two types of nematodes that survive entirely on the heat that comes from inside the Earth."

The image at the top of the page is an artistic rendition of a nomad object wandering the interstellar medium. The object is intentionally blurry to represent uncertainty about whether or not it has an atmosphere. A nomadic object may be an icy body akin to an object found in the outer Solar System, a more rocky material akin to asteroid, or even a gas giant similar in composition to the most massive Solar System planets and exoplanets.

Journal reference: Monthly Notices of the Royal Astronomical Society

The Daily Galaxy via The Kavli Foundation


No life on these cold corpses. Sorry scientists, keep coming up with questions.

Knize10 apparently didn't read the article. If Earth somehow left its orbit and began drifting through interstellar space, life would perservere, as there are known extremophiles living deep under the earth's surface (of course all plants and non-microscopic animals would soon die). And if life could survive here, then it could survive on other planets that have been seperated from their parent stars via orbital distortion, supernova explosion, etc. Some of those rogue planets may indeed bear life.

If such a high proportion of rogue planet numbers to
numbers of stars in the Milky Way is roughly true,
it raises anew the question: How often do large
massive objects pass close to our sol system over
hundreds of millions of years? Wouldn't this raise
the perturbation level on our Oort cloud, accounting
for some extinction events?

I agree. That is a very good and valued point !It makes one think about the topic: "Gays and Lesbians on other they exist ? Free of the stupidity and black magic of man-made religion and the outrageous fairy tales of our Bible...same-sex attracted aliens are probably living free of hate, ridicule and discrimination. Nature has a way of keeping the population in check;(as best as it can.)If a segment of the population is exclusively homosexual,(say 5%),them most of these beings would not pro-create. This means millions of less new born. It is so simple and rational a's controversial! This of course,among religiously fueled hate-mongers that can only see humanity in a hetero-centrist way. Gay aliens in other solar systems or on rogue planets with a sun can and probably do exist !

Other more conservative or even more reasonable estimates put the Rogue planet count at 2 rogues for every star. My thoughts are its something like a 50 rogues for every star, maybe 250:1 if you include much smaller planetoid objects.

All I'm saying is if the ratio is anywhere near 100,000 rogues for each star, that is most definitely a red flag situation when it comes to solar system interference and extinction events.

Are these nomad or rogue planets part of Dark Matter? If so, what percentage of Dark Matter might they account for?

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)