Hubble Spots Wreckage of Earth-Like Planets Near Dead Stars

Hubble Spots Wreckage of Earth-Like Planets Near Dead Stars

debris falling into a dead star News Edit

The discovery sheds the light of dim, white fusion on what Earth will be like in 5 billion years.

Scientists searching with the Hubble Space Telescope have found the pieces of Earth sized planets in a fairly surprising place: orbiting dead stars. A pair of white dwarf stars in the cluster Hyades, about 150 light-years from Earth, is being polluted by asteroid-like debris falling into them. "When these stars were born, they built planets," said Jay Farihi of the University of Cambridge, "and there's a good chance they currently retain some of them. The material we are seeing is evidence of this. The debris is at least as rocky as the most primitive terrestrial bodies in our solar system." Hubble's spectrograph indicates that the rocky debris around the white dwarfs is high in silicon and low in carbon, which matches the general composition of rocky material in our solar system and the general composition of Earth itself. It's what Farihi calls chemical evidence for the building blocks of planets composed a lot like Earth. It could indicate that rocky planets are the trend around the cosmos.

White Dwarfs are the very dense, burnt out remains of dead stars. They are very dense and have powerful gravity, which Farihi thinks is responsible for the destruction of the various primitive planetoids remaining in their systems. Those shattered bits of rock are falling into a ring around the dwarfs, and then being pulled into the atmosphere of the dwarf itself. "It's difficult to imagine another mechanism than gravity that causes material to get close enough to rain down onto the star," said Farihi, noting that "Normally white dwarfs are like blank pieces of paper, containing only the light elements hydrogen and helium."

It's likely that a similar fate could befall our solar system when the sun burns out, disrupting the balance of gravity between the sun and Jupiter. Rocky asteroids and planets approaching the dying sun will break up, being pulled into a similar ring and then raining down onto the dead star. Farihi's team intends to continue studying Hubble data about white dwarfs, and in the future they hope that they will be able to not only see more about the rocks' composition, but also about the composition of their parent bodies.

Image: NASA

If you like to keep up with the latest science news, you'll probably enjoy the Geekend Update, our weekly science show. New episodes drop each Saturday.

Permalink

I actually read that as

JonB:
Hubble Spots Wreckage of Earth-Like Planets Near Death Stars

OT: Depressing news is depressing.

Cool, I'll be long dead so I won't get to see what happens when our star dies. ):

Anyone up for an extraterrestrial archeology trip? Sounds like a great site to check out if we ever get out of our own solar system...

Dr.Awkward:
Anyone up for an extraterrestrial archeology trip? Sounds like a great site to check out if we ever get out of our own solar system...

It could be the plot of Indiana Jones 5: The Space Crusade.

And remember, this could be evidence that the Reapers are only 150 light years away. Watch the skies people, watch the skies.

Wait, white dwarfs may be dense but they don't have MORE mass than the star itself. In space size of the object doesn't matter, only it's mass. So if our sun turned into a white dwarf (or even a black hole) right this very instant and retained exactly 100% of it's mass, nothing would change for the planets/debris orbiting it.

Since a white dwarf will have less mass than the original star (it sheds a large amount of mass during final stages, blows off outer layers) wouldn't that mean the orbits of planets/debris would get bigger and everything would be flung outwards, further away? The dwarf not going to start pulling things towards itself because the overall gravitational field is weaker compared to the original star.

I'm obviously not trying to argue with the physicists who observed this...but yeah, I'm confused :S

Yuuki:
Wait, white dwarfs may be dense but they don't have MORE mass than the star itself. In space size of the object doesn't matter, only it's mass. So if our sun turned into a white dwarf (or even a black hole) right this very instant and retained exactly 100% of it's mass, nothing would change for the planets/debris orbiting it.

Since a white dwarf will have less mass than the original star (it sheds a large amount of mass during final stages, blows off outer layers) wouldn't that mean the orbits of planets/debris would get bigger and everything would be flung outwards, further away? The dwarf not going to start pulling things towards itself because the overall gravitational field is weaker compared to the original star.

I'm obviously not trying to argue with the physicists who observed this...but yeah, I'm confused :S

No you're right, if anything the mass decreases as contractions from the helium burning expel material. However, if you're referring to them saying that white dwarfs are "very dense and have powerful gravity" they might possibly mean the gravity becomes more powerful at its surface as the gravitational pressure makes the whole star incredibly dense.
Would be my guess at least, because otherwise it's not exactly that strong... 1,44 times our sun's mass tops or else it couldn't become a whife dwarf. Either that or the tidal forces are stronger than I thought.

Quaxar:
However, if you're referring to them saying that white dwarfs are "very dense and have powerful gravity" they might possibly mean the gravity becomes more powerful at its surface as the gravitational pressure makes the whole star incredibly dense.
Would be my guess at least, because otherwise it's not exactly that strong... 1,44 times our sun's mass tops or else it couldn't become a whife dwarf. Either that or the tidal forces are stronger than I thought.

The gravitational field at the surface will be a lot stronger, correct, but from a certain distance onwards the amount of "bend" exerted on spacetime (which is pretty much what gravity is) at the outer rim remains unchanged...

image

I always click on these threads hoping I'll understand what is happening. But I don't. Me and science don't get on well

CriticalMiss:

Dr.Awkward:
Anyone up for an extraterrestrial archeology trip? Sounds like a great site to check out if we ever get out of our own solar system...

It could be the plot of Indiana Jones 5: The Space Crusade.

And remember, this could be evidence that the Reapers are only 150 light years away. Watch the skies people, watch the skies.

Or possibly Galactus, I'd keep an eye on that purple-helmeted world destroyer.

By Earth-like, do you mean about the same size as Earth, or has/had the potential to host life? I've seen the term used to mean either or.

By Earth-like, the scientists mean "made of rocks", or more specifically "made of rocks with a similar elemental composition to those found on Earth".

Not Earth sized like the article says, because there's only pieces of them left, nor potential to host life, because you'd need to know what and where they were before they were smashed to bits to figure that out.

Except the sun will grow brighter and kill off surface life along with evaporating oceans in 150-250 million years. So we'll be a lifeless rock long before it happens.

soren7550:
By Earth-like, do you mean about the same size as Earth, or has/had the potential to host life? I've seen the term used to mean either or.

Typically, "earth-like" refers to planets with a composition, size and density similar to Earth. A magnetic field is also important, since it protects the planet against stellar winds, which can strip away an unprotected atmosphere in short order (such as what may have happened to Mars).

In addition, its distance from its primary is important; conventional understanding implies that the presence of liquid water is a must for a planet to be able to support life.

Basically, a life-supporting planet would likely need liquid water, and for liquid water to exist, the planet would need an atmosphere and the right distance from its sun to sustain temperatures that keep that water liquid (unless it's a world like Jupiter's moon Europa, which is a whole different story).

Lemme know when you find a few planets orbitting a Red Dwarf, THEN I'll be worried.

In the meantime, this is very interesting work...and kindd of creepy that what we're finding more and more of out there is not life...but evidence of death, and lots of it.

soren7550:
By Earth-like, do you mean about the same size as Earth, or has/had the potential to host life? I've seen the term used to mean either or.

it seems that this time it meant "made of rock". They did notice the silicon/carbon amounts similar to that of earth but beside that its jsut a asteroid that could have been a planet.

In addition, its distance from its primary is important; conventional understanding implies that the presence of liquid water is a must for a planet to be able to support life.

Correction: presensce of liquid water is a must for a planet to support human life. We dont know what kind of lifeforms are out there. there could be a silicon based living rock that takes 1 earth year to move its legs and it would still be a lifeform and wouldnt need liquid water. Thinking water is needed for life is quite primitive way of looking at it.

Karthesios:
(unless it's a world like Jupiter's moon Europa, which is a whole different story).

Actually it would be interesting to know that story, in a short not scientific paper length type of style.

 

Reply to Thread

Log in or Register to Comment
Have an account? Login below:
With Facebook:Login With Facebook
or
Username:  
Password:  
  
Not registered? To sign up for an account with The Escapist:
Register With Facebook
Register With Facebook
or
Register for a free account here