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APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:08 am
by APOD Robot
[img]http://apod.nasa.gov/apod/calendar/S_160405.jpg[/img] Cancri 55 e: Climate Patterns on a Lava World
Explanation: Why might you want to visit super-earth Cancri 55 e? Its extremely hot climate would be a deterrent, as
mornings on this world might bring fresh lava flows. Discovered in 2004, the planet
Cancri 55 e has twice the diameter of our Earth and about 10 times Earth's mass. The planet orbits its 40 light-year distant
Sun-like star well inside the orbit of Mercury, so close that it is
tidally locked, meaning that it always keeps the same face toward the object it orbits -- like our Moon does as it orbits the Earth. Astronomers have
recently measured temperature changes on this exoplanet using
infrared observations with the
Spitzer Space Telescope. Given these observations, an artist created the
featured video with educated guesses about what one revolution of Cancri 55 e might look like. Depicted are full phase, when the planet is fully illuminated, and new (dark)
phase when it passes near the line of sight to Earth. The illustrated red bands on the
Cancri 55 e indicate bands of lava that might flow on the planet. A recent density determination for
55 Cancri e show that this exoplanet is
not made primarily of
oxygen, as are the inner planets in our Solar System, but rather of
carbon. Therefore, one reason to visit
Cancri 55 e might be to study its core, because this planet's great internal pressure might be sufficient to make the carbon found there into
one huge diamond.
[/b]
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:24 am
by Ann
55 Cancri e is another truly Earth-unlike exoplanet. Chances are that every exoplanet we are able to study in any sort of detail within the next few years will turn out to be quite different from the Earth.
Are there no truly Earthlike planets out there? Yes, there probably are, given how vast the universe is. But how few and far between will they turn out to be?
As a kid, I read some science fiction where Mars and Venus had their own populations of indigenous advanced life, indeed of technological civilizations. That is a far cry from reality. The jury is still out on whether or not there is any life on Mars, but it seems certain that any Martian life forms will be no more advanced than microbes. And we have reasons to think that Venus is as dead as a doornail.
Considering how rare the Earth is in the solar system, which has definitely proved itself capable of producing an incredible wealth of life and advanced life forms, we should not expect any planet that can be studied with Earthly (or space-based) telescopes to prove itself amenable to life.
How rare is Earth really?
Ann
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:41 am
by bystander
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:47 am
by MrZorg
HA. this is a funny post. As IF... we can tell a planet it tidal locked 40 light years away, but can't find planet X which we have been searching for since the late 1800's... don't you find that funny?
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:47 am
by neufer
Ann wrote:
How rare is Earth really?
https://en.wikipedia.org/wiki/Kepler_%28spacecraft%29 wrote:
<<In March 2011, astronomers at NASA's Jet Propulsion Laboratory (JPL) reported that about "1.4 to 2.7 percent" of all Sun-like stars are expected to have earthlike planets "within the habitable zones of their stars". This means there are "two billion" of these "Earth analogs" in the Milky Way alone. The JPL astronomers also noted that there are "50 billion other galaxies".>>
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 6:03 am
by Ann
neufer wrote:Ann wrote:
How rare is Earth really?
https://en.wikipedia.org/wiki/Kepler_%28spacecraft%29 wrote:
<<In March 2011, astronomers at NASA's Jet Propulsion Laboratory (JPL) reported that
about "1.4 to 2.7 percent" of all Sun-like stars are expected to have earthlike planets "within the habitable zones of their stars". This means there are "two billion" of these "Earth analogs" in the Milky Way alone.
Well, Mars and Venus are sort of earthlike planets within the habitable zone of their star. Not that that fact means they are teeming with life.
When I say earthlike planets, I mean truly earthlike planets. I mean planets with a robust biosphere. How many such planets are there in the Milky Way? I don't think we know anything about that. And I object to the rather careless use of the expression "earthlike planets" or "Earth analogs".
Ann
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 6:14 am
by Nitpicker
I imagine that many "Earth analogs" only have a robust biosphere for a fraction of their lives. If some future Earth scientists travel to another star system and their descendants return, only to find that life no longer exists on Earth, would they classify it as an "Earth analog"?
(But I think Cancri 55 e is a "Super Earth" rather than an "Earth analog". Not sure that the definitions are agreed upon, either way.)
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 11:18 am
by RonDavis
It’s hard to imagine a rocky planet where a large part of the surface is liquified by the heat of its star. Rather, that would be hard, except that we happen to live on such a planet.
On any such planet, the lava will feel cool to any inhabitant that dwells on a solid portion of the surface, because
☀ the lava and the air (assuming there is air) will be at nearly the same temperature,
☀ the 2nd law of thermodynamics dictates that the interior of an inhabitant will be warmer than its surroundings, and
☀ liquids conduct heat to or from solids more effectively than gases do.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 11:23 am
by Ele6
APOD Robot wrote:this exoplanet is
not made primarily of
oxygen, as are the inner planets in our Solar System
Oxygen?
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 11:54 am
by Asterhole
What made this planet so "easily" hypothesized is the fact it orbits so close to its parent star - and its size. Using only infrared measurements give us a tiny glimpse of what a truly alien world would be like. What really may be out there could be beyond our imagination...
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 11:56 am
by neufer
Ann wrote:neufer wrote:Ann wrote:
How rare is Earth really?
https://en.wikipedia.org/wiki/Kepler_%28spacecraft%29 wrote:
<<In March 2011, astronomers at NASA's Jet Propulsion Laboratory (JPL) reported that
about "1.4 to 2.7 percent" of all Sun-like stars are expected to have earthlike planets "within the habitable zones of their stars". This means there are "two billion" of these "Earth analogs" in the Milky Way alone.
When I say earthlike planets, I mean truly earthlike planets. I mean planets with a robust biosphere. How many such planets are there in the Milky Way?
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 12:06 pm
by borborygmy
The planet orbits its 40 light-year distant Sun-like star well inside the orbit of Mercury, so close that it is tidally locked, meaning that it always keeps the same face toward the object it orbits -- like our Moon does as it orbits the Earth.
Does tidally locked mean the bigger body holds the smaller body in place, so it can't turn? And is that based on distance? If the moon was a little further out in orbit, could it then rotate at a different speed? Is rotation independent of distance between two bodies, until they get so close that then, the smaller one is tidally locked and no longer rotates?
Someone teach me physics right now.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 12:54 pm
by rstevenson
Ele6 wrote:APOD Robot wrote:this exoplanet is
not made primarily of
oxygen, as are the inner planets in our Solar System
Oxygen?
From
the Wikipedia article on Earth ...
[Earth] is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%), with the remaining 1.2% consisting of trace amounts of other elements.
Of course, most of that oxygen is bound up in compounds such as silica, alumina, lime, and so on.
Rob
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 1:08 pm
by Guest
I think you meant to say that the inner planets of our Solar System are primarily made of SILICON.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 1:26 pm
by RJN
It has been pointed out that a tidally locked planet would not have "mornings", as indicated in the (original) text. Although technically possible even then at some places through libration, the APOD text has now been updated to be more consistent. I apologize for the oversight. - RJN
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 2:54 pm
by Fred the Cat
Pretty amazing that for $70 you get a recent update on
The Search for Exoplanets from an excellent professor. I've seen these courses recommended though their content can be searched and found on the internet for free. I think it sounds worth the cost but everyone as their own budget. I don't mind supporting well done and topical sources of education.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 3:08 pm
by Chris Peterson
rstevenson wrote:From
the Wikipedia article on Earth ...
[Earth] is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%), with the remaining 1.2% consisting of trace amounts of other elements.
Of course, most of that oxygen is bound up in compounds such as silica, alumina, lime, and so on.
That's useful information in considering how Earth formed, but in other respects it's more interesting to consider the
crustal elemental abundance, which is overwhelmingly dominated by oxygen (at 46%), followed by silicon (28%), and everything else, including iron, in the single digits.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:36 pm
by geckzilla
MrZorg wrote:HA. this is a funny post. As IF... we can tell a planet it tidal locked 40 light years away, but can't find planet X which we have been searching for since the late 1800's... don't you find that funny?
Isn't it amazing what we can learn when something passes in front of a star? Any search for a so-called "planet X" relies on different techniques, making finding such a planet a lot more difficult than one might imagine.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 4:50 pm
by MarkBour
rstevenson wrote:Ele6 wrote:APOD Robot wrote:this exoplanet is
not made primarily of
oxygen, as are the inner planets in our Solar System
Oxygen?
From
the Wikipedia article on Earth ...
[Earth] is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%), with the remaining 1.2% consisting of trace amounts of other elements.
Of course, most of that oxygen is bound up in compounds such as silica, alumina, lime, and so on.
Rob
It seems most sensible to assume that our Solar system coalesced from a fairly homogeneous cloud of material. Is there a simulation that has been done that could start from such a cloud and come anywhere close to explaining the differing compositions of our star and planets et al, as one moves from the center outward? The next question would be, how could the Cancri 55 system, a mere 40 light years away, come up with a planet that is so different in composition? Or does that fit our own system, were a large planet to have formed inside the orbit of Mercury?
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 5:15 pm
by Chris Peterson
MarkBour wrote:It seems most sensible to assume that our Solar system coalesced from a fairly homogeneous cloud of material. Is there a simulation that has been done that could start from such a cloud and come anywhere close to explaining the differing compositions of our star and planets et al, as one moves from the center outward?
Yes. The important point is that almost all of the material from which our system formed (any system, really) was just one element: hydrogen. Everything else was present only in trace amounts. Too near the Sun, and hydrogen is blown away. So inner planets are terrestrial. They are made up of iron and silicon- the iron settled in their cores, the silicon bound with oxygen in their outer layers. The outer planets are mostly still hydrogen, although they have- in total- even more heavy elements than we find in the terrestrial planets. The amounts are just less in terms of percentage. Also, far from the Sun, volatile molecules like water, carbon dioxide, methane, and many others have survived. Thus we have a vast region of ice bodies very far out.
There is little to suggest that this structure isn't representative of most other planetary systems, as well.
The next question would be, how could the Cancri 55 system, a mere 40 light years away, come up with a planet that is so different in composition? Or does that fit our own system, were a large planet to have formed inside the orbit of Mercury?
While all planetary systems form from contaminated hydrogen clouds, the actual ratios of the contaminants vary (as we see in the differences between many nebulas). Consider the possible differences in heavy element ratios of the precursor nebula, and the fact that planetary systems are chaotic and planets can apparently move suddenly and rapidly into very different orbits, and it's not difficult to imagine that different systems will display very different characteristics, even if the broad principles of formation are the same.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 5:47 pm
by Ann
neufer wrote:Ann wrote:neufer wrote:
When I say earthlike planets, I mean truly earthlike planets. I mean planets with a robust biosphere. How many such planets are there in the Milky Way?
Nice!
Or maybe we're taking about
the answer to life, the universe and everything... 42?
Ann
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 7:31 pm
by Boomer12k
OK... got my Diamond Mining Equipment.... Ahm gonna be RICH!!!!!! HAHAHAHAHAHAHA....
At ten times the mass, they aught to be closer to the surface too.
Back in the 70's, I did a calculation... 1% of 1% of 1%... is about 20,000 out of 200 Billion Stars....that might contain an Earth like planet and MAYBE contain life.... way too far apart for contact, if relatively spaced throughout the galaxy... but a possibility....
It is interesting that this planet is twice the size of Earth.... they just need to spot smaller ones... and BLUE ones... pretty much a dead giveaway... I know they eventually will, we just need the sensitive detection methods.
I am sure they are working on it.... only a matter of time.
:---[===] *
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 7:33 pm
by heehaw
It looks very much as if the Universe is infinite in size, from the microwave background results. If that is so, there are infinitely many Earth-like planets, including infinitely many on which there is a US election underway at the moment. If the Universe is BIG but is not infinite, then we don't know how many Earth-like planets there are bearing life.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 8:22 pm
by Chris Peterson
heehaw wrote:It looks very much as if the Universe is infinite in size, from the microwave background results. If that is so, there are infinitely many Earth-like planets, including infinitely many on which there is a US election underway at the moment. If the Universe is BIG but is not infinite, then we don't know how many Earth-like planets there are bearing life.
How does the nature of the microwave background argue for an infinite sized universe? As we lack any observations outside the observable universe, and our cosmological theory is very incomplete in some respects, I'd suggest that we really have no idea at all beyond speculation whether the Universe itself is finite or infinite.
Re: APOD: Cancri 55 e: Climate Patterns on a... (2016 Apr 05)
Posted: Tue Apr 05, 2016 10:22 pm
by MarkBour
Chris Peterson wrote:... and the fact that planetary systems are chaotic and planets can apparently move suddenly and rapidly into very different orbits ...
Good point. I forgot about this. So, for example, just because Janssen is very close to its star does not imply it began its formation there, or that it has always lived there. According to Wikipedia, it currently has an orbit only about 1/20th the radius of Mercury's orbit !
