Exoplanet discoveries

[beecee]

9 hours ago, Raider5678 said:

I, like others, believe in the rare earth Hypothesis. 

So yes, unique, however probably not the only one.

 

7 hours ago, Moontanman said:

 

Rare Earth? You mean the Hypothesis of the book "Rare Earth"? While many if not most of the assertions in that book have been discounted we really don't know enough really make a call on that one way or another.

The idea that a planet would be just like the Earth is more of a science fiction dream than reality. The Earth could be habitable somewhat closer to the sun and quite a bit further away from the sun but the planet would not necessarily be habitable by humans.

I havn't read the book "Rare Earth"  and took the unique comment to mean "one off" My idea of an earth like planet, is one that will support life as we know it. That does not rule out the possibility of life as we don't know it.

And yes most certainly we have no empirical evidence to show that life exists anywhere else but on Earth, but as I have said many times, when one considers the "near infinite" extent and content of just our observable universe, and the stuff of life being everywhere we look, I see it as rather reasonable to conclude that life should arise elsewhere.

Many cosmologists and scientists today believe that evidence of the existence of life elsewhere may reveal itself sooner then later. If it did happen that life only existed on this fart arse little blue orb, then I believe it would raise far many more questions.

6 hours ago, Raider5678 said:

Also, what slight hints do you have that there are planets more suitable for humans than Earth? I didn't see that and that'd be interesting. 

 What reasons does anyone have to believe that there cannot be other planets more suitable for humans? We just don't know at this time.

Edited January 7, 2018 by beecee

[Moontanman]

59 minutes ago, beecee said:

 

I haven't read the book "Rare Earth"  and took the unique comment to mean "one off" My idea of an earth like planet, is one that will support life as we know it. That does not rule out the possibility of life as we don't know it.

The Rare Earth hypothesis deals with complex life as we know it but that doesn't mean humans could live on it. I honestly think that being fit for humans is another thing entirely from just complex life. 

59 minutes ago, beecee said:

And yes most certainly we have no empirical evidence to show that life exists anywhere else but on Earth, but as I have said many times, when one considers the "near infinite" extent and content of just our observable universe, and the stuff of life being everywhere we look, I see it as rather reasonable to conclude that life should arise elsewhere.

I agree, I would be amazed if there isn't life on a body in our solar system other than Earth. Most scientists in that field think life is inevitable given the correct conditions. In fact in " Rare Earth" by Ward and Brownlee they think life is widespread, single celled, but the Rare part is complex life. 

59 minutes ago, beecee said:

Many cosmologists and scientists today believe that evidence of the existence of life elsewhere may reveal itself sooner then later. If it did happen that life only existed on this fart arse little blue orb, then I believe it would raise far many more questions.

 What reasons does anyone have to believe that there cannot be other planets more suitable for humans? We just don't know at this time.

Other planets more suitable for complex life is the idea, we have evolved to fit the Earth, that might limit a planet's usefulness to humans. On the other hand planets more suitable for complex life than the Earth can be argued easily... 

The Earth is not a perfect fit for life, life has evolved to fit Earth. Other planets could be rendered uninhabitable simply by varying amounts of trace gases or metals in the planet. Something as simple as too much mercury could be a deal breaker.   

I look to Titan, if a second genesis of life completely different than Earth life has arisen in our solar system it would have a profound impact on the question of life in the universe. 

[Outrider]

On 1/5/2018 at 7:25 PM, Airbrush said:

Maybe you don't need to use the laser for 20+ years because I suspect the author proposes that from Earth, a laser could push the Sprite to a speed of 0.2c, and maybe that speed can be reached in just a few years or even months from Earth?

Ok that makes more sense than what I said. From wiki (I'll post a link later) "A phased array of ground-based lasers would then focus a light beam on the crafts' sails to accelerate them one by one to the target speed within 10 minutes, with an average acceleration on the order of 100 km/s2, and an illumination energy on the order of 1 TJ delivered to each sail"

Thats gonna be about 100 gigawatt for 10 minutes for each of 1,000 craft or the average output of a nuclear plant for seven days. Wiki says one by one but I have read other articles stating they might have 10 or more probes per sail.

On 1/5/2018 at 7:25 PM, Airbrush said:

How small is a Sprite?

3.5 x 3.5 cm and weighs 4 grams. But the Sprite is the prototype. The probe that actually makes the journey will be named StarChip and be 1 centimeter square and weigh 1 gram. The Sprite is solar powered and uses radio to communicate. StarChip will have a battery and use laser to communicate. 

On 1/5/2018 at 7:25 PM, Airbrush said:

How capable of a payload? 

4 cameras, 4 processors, 4 thrusters, battery, navigation equipment and a laser for communication are planned.

Launch is scheduled for 2036.

I got most of that information from here.

https://en.m.wikipedia.org/wiki/Breakthrough_Starshot

On 1/5/2018 at 7:25 PM, Airbrush said:

How much info can it send from a tiny transmitter?

I don't know and I don't know how they plan to direct the cameras from over 4 ly away. I suspect the probes are on their own once they are accelerated. 

On 1/5/2018 at 7:43 PM, Raider5678 said:

Better question, what's its battery life?

A 150 mg atomic battery, powered by plutonium-238 or americium-241, is planned.

 

Edited January 7, 2018 by Outrider

[Moontanman]

2 hours ago, Outrider said:

Ok that makes more sense than what I said. From wiki (I'll post a link later) "A phased array of ground-based lasers would then focus a light beam on the crafts' sails to accelerate them one by one to the target speed within 10 minutes, with an average acceleration on the order of 100 km/s2, and an illumination energy on the order of 1 TJ delivered to each sail"

Thats gonna be about 100 gigawatt for 10 minutes for each of 1,000 craft or the average output of a nuclear plant for seven days. Wiki says one by one but I have read other articles stating they might have 10 or more probes per sail.

3.5 x 3.5 cm and weighs 4 grams. But the Sprite is the prototype. The probe that actually makes the journey will be named StarChip and be 1 centimeter square and weigh 1 gram. The Sprite is solar powered and uses radio to communicate. StarChip will have a battery and use laser to communicate. 

4 cameras, 4 processors, 4 thrusters, battery, navigation equipment and a laser for communication are planned.

Launch is scheduled for 2036.

I got most of that information from here.

https://en.m.wikipedia.org/wiki/Breakthrough_Starshot

I don't know and I don't know how they plan to direct the cameras from over 4 ly away. I suspect the probes are on their own once they are accelerated. 

A 150 mg atomic battery, powered by plutonium-238 or americium-241, is planned.

 

 

Makes you think, if we can do that what could aliens do if they were a few thousand years ahead of us! I envy the young people today, they will get to see things we only dreamed of! 

[Outrider]

3 hours ago, Moontanman said:

Makes you think, if we can do that what could aliens do if they were a few thousand years ahead of us!

Which makes some people like me and Fermi wonder where they are at. Maybe it will turn out that the UFO nuts were right all along.

3 hours ago, Moontanman said:

I envy the young people today, they will get to see things we only dreamed of! 

Yes I do as well. If Breakthrough Starshot stays on schedule (they won't) I will be 96 when the data starts coming in. I doubt I will make it.

OTOH I am very grateful for what I have got to see. The Voyager spacecraft forever changed our views of the moons of gas and ice giants. I got to see Shoemaker-Levy slam into Jupiter. Recently we had a vistor from another star system Oumuamua. And its been confirmed that black holes do merger and neutron star mergers are the source of much (probaly all) of our heaviest elements. 

Its been a fine ride and I can't complain but sometimes I still do.

I guess of all the upcoming things that I probably will see JWST excites me the most.

[Raider5678]

57 minutes ago, Outrider said:

Yes I do as well.

1

I do not.

But that's for other reasons.

 

 

5 hours ago, Moontanman said:

Makes you think, if we can do that what could aliens do if they were a few thousand years ahead of us!

This is one of the main reasons I lean more towards the rare Earth Hypothesis.

Simply because, in my opinion, if life was common, then surely there are more advanced aliens then us.

[Moontanman]

1 hour ago, Raider5678 said:

I do not.

But that's for other reasons.

 

 

This is one of the main reasons I lean more towards the rare Earth Hypothesis.

Simply because, in my opinion, if life was common, then surely there are more advanced aliens then us.

I am not sure what that has to do with the Rare Earth hypothesis? 

[Raider5678]

4 hours ago, Moontanman said:

I am not sure what that has to do with the Rare Earth hypothesis? 

If Earth had the right conditions for life to form, then if there were more planets similar to Earth there'd be more life.(speculation)

Less life means it points to fewer planets like Earth.(speculation)

Either way, this has gotten off track from the Exoplanet discoveries.(Not speculation)

 

 

[Moontanman]

28 minutes ago, Raider5678 said:

If Earth had the right conditions for life to form, then if there were more planets similar to Earth there'd be more life.(speculation)

Less life means it points to fewer planets like Earth.(speculation)

Either way, this has gotten off track from the Exoplanet discoveries.(Not speculation)

 

 

I see where you are coming from, the conditions to allow life to form are far and away from the conditions on Earth today. The Earth today looks as though it is perfect for life but in fact life has both evolved to fit Earth and been instrumental in making the Earth more suitable for life.  Maybe someday, hopefully while I still around,  we will find life outside the Earth. My point in all of this is that a planet doesn't have be much like Earth for life to exist there. 

[Area54]

18 hours ago, Moontanman said:

IThe Earth today looks as though it is perfect for life but in fact life has both evolved to fit Earth and been instrumental in making the Earth more suitable for life. 

I'm not sure I agree with your last statement. Life has made the Earth more suitable for the life that currently inhabits it. I'm sure the Archean microbiota found the efforts of the cyanobacteria that oxygenated the atmosphere most unwelcome, disrupting the ideal conditions they had enjoyed for a billion years.

[Moontanman]

14 minutes ago, Area54 said:

I'm not sure I agree with your last statement. Life has made the Earth more suitable for the life that currently inhabits it. I'm sure the Archean microbiota found the efforts of the cyanobacteria that oxygenated the atmosphere most unwelcome, disrupting the ideal conditions they had enjoyed for a billion years.

Yes, you are correct, I was thinking of the life that currently inhabits the surface, complex life. 

[Airbrush]

On ‎1‎/‎7‎/‎2018 at 2:32 AM, Outrider said:

 The probe that actually makes the journey will be named StarChip and be 1 centimeter square and weigh 1 gram. The Sprite is solar powered and uses radio to communicate. StarChip will have a battery and use laser to communicate. 

4 cameras, 4 processors, 4 thrusters, battery, navigation equipment and a laser for communication are planned.

Launch is scheduled for 2036.

I got most of that information from here.

https://en.m.wikipedia.org/wiki/Breakthrough_Starshot

I don't know and I don't know how they plan to direct the cameras from over 4 ly away. I suspect the probes are on their own once they are accelerated. 

A 150 mg atomic battery, powered by plutonium-238 or americium-241, is planned.

 

How can you make 4 cameras, 4 processors, 4 thrusters, battery, nav quip, and laser packed into one centimeter square and weigh only one gram?  The 150mg atomic battery will take up 15% of the gram.

Easy to direct the cameras.  Just lock onto the target star and/or the planet and use them for reference.  Once it nears the star could the laser sails soak up solar power?

On ‎1‎/‎6‎/‎2018 at 5:28 PM, Moontanman said:

Rare Earth?  You mean the Hypothesis of the book "Rare Earth"?  While many if not most of the assertions in that book have been discounted we really don't know enough really make a call on that one way or another.

Although I must agree with most of your assertions, I was wondering if you could give us a few examples of Rare Earth Hypothesis being discounted.  Rare Earth explains the Fermi Paradox.

Edited January 8, 2018 by Airbrush

[Moontanman]

4 hours ago, Airbrush said:

How can you make 4 cameras, 4 processors, 4 thrusters, battery, nav quip, and laser packed into one centimeter square and weigh only one gram?  The 150mg atomic battery will take up 15% of the gram.

Easy to direct the cameras.  Just lock onto the target star and/or the planet and use them for reference.  Once it nears the star could the laser sails soak up solar power?

Although I must agree with most of your assertions, I was wondering if you could give us a few examples of Rare Earth Hypothesis being discounted.  Rare Earth explains the Fermi Paradox.

 

Some of the ideas behind Rare Earth such as our Moon being both necessary and extremely unlikely are now thought to be discounted. The idea the moon was rare was based on the idea that planetary collisions were unlikely. Now it is thought that planetary mashups like the one that formed the moon happened to all the inner and maybe even the outer planets. This would indicate that large moons are not as unlikely as once thought. Mercury is now thought to be in it's current state due to a massive collision that blew most of the planet away but was too hard to allow the shrapnel to form a moon. The current condition of Venus can also be explained by a giant impact and even Mars is thought to have been the result of large impacts. More importantly the idea that having a large moon is necessary for life is questionable as well. other problems are discussed in this wiki.

 

https://en.wikipedia.org/wiki/Rare_Earth_hypothesis

 

Quote

A large moon may neither be rare nor necessary[edit]

The requirement of a large moon (Rare Earth equation factor {\displaystyle f_{m}}) has also been challenged. Though even if it were required, such an occurrence may not be as unique as predicted by the Rare Earth Hypothesis. Recent work by Edward Belbruno and J. Richard Gott of Princeton University suggests that giant impacts such as those that may have formed the Moon can indeed form in planetary trojan points (L4 or L5 Lagrangian point) which means that similar circumstances may occur in other planetary systems.[119]

Collision between two planetary bodies (artist concept).

Rare Earth's assertion that the Moon's stabilization of Earth's obliquity and spin is a requirement for complex life has been questioned. Kasting argues that a moonless Earth would still possess habitats with climates suitable for complex life and questions whether the spin rate of a moonless Earth can be predicted.[78] Although the giant impact theory posits that the impact forming the Moon increased Earth's rotational speed to make a day about 5 hours long, the Moon has slowly "stolen" much of this speed to reduce Earth's solar day since then to about 24 hours and continues to do so: in 100 million years Earth's solar day will be roughly 24 hours 38 minutes (the same as Mars's solar day); in 1 billion years, 30 hours 23 minutes. Larger secondary bodies would exert proportionally larger tidal forces that would in turn decelerate their primaries faster and potentially increase the solar day of a planet in all other respects like earth to over 120 hours within a few billion years. This long solar day would make effective heat dissipation for organisms in the tropics and subtropics extremely difficult in a similar manner to tidal locking to a red dwarf star. Short days (high rotation speed) causes high wind speeds at ground level. Long days (slow rotation speed) cause the day and night temperatures to be too extreme.[120]

Many Rare Earth proponents argue that the Earth's plate tectonics would probably not exist if not for the tidal forces of the Moon.[121][122] The hypothesis that the Moon's tidal influence initiated or sustained Earth's plate tectonics remains unproven, though at least one study implies a temporal correlation to the formation of the Moon.[123]Evidence for the past existence of plate tectonics on planets like Mars[124] which may never have had a large moon would counter this argument. Kasting argues that a large moon is not required to initiate plate tectonics.[78]

Other critiques are offered in this wiki article as well. More importantly is the fact that we only have one data point, trying to draw a curve from one data point is not possible. 

There one idea that I don't think Ward And Brownlee mentioned in their book is why Earth is not a Mini Neptune. The collision that formed Luna might be the reason we are not a water planet with no land but again we have one data point.

The Fermi paradox can be explained many ways but until we get more data points it's just speculation. A planet strikingly different from Earth might harbor life and even be friendlier to complex life than the Earth.  

This discussion is a bit OT, we can discuss this further if someone wants to start another thread or we can go to my thread which is similar "super habitable planets" 

[beecee]

2 hours ago, Moontanman said:

 

Some of the ideas behind Rare Earth such as our Moon being both necessary and extremely unlikely are now thought to be discounted. The idea the moon was rare was based on the idea that planetary collisions were unlikely. Now it is thought that planetary mashups like the one that formed the moon happened to all the inner and maybe even the outer planets. This would indicate that large moons are not as unlikely as once thought. Mercury is now thought to be in it's current state due to a massive collision that blew most of the planet away but was too hard to allow the shrapnel to form a moon. The current condition of Venus can also be explained by a giant impact and even Mars is thought to have been the result of large impacts. More importantly the idea that having a large moon is necessary for life is questionable as well. other problems are discussed in this wiki.

The hypothesis re the supposed necessity of our Moon, never really grabbed me at all. I think from memory, part of the reasoning was that the comparitively large Moon, helped stabilise the Earth's rotation about its axis to the few degrees we do experience and is apparently responsible for the Ice ages. Without it, so the hypothesis goes, Earth's tilt would have varied by much more, creating catastrophic conditions that would be unsuitable for life as we know it. And of course we don't see that sort of reaction with the Pluto/Charon system, where the size of the Moon in comparison to the planet, [oops, sorry, minor planet  ] is much closer aligned then with Earth and our own Moon.

Quote

 The Fermi paradox can be explained many ways but until we get more data points it's just speculation. A planet strikingly different from Earth might harbor life and even be friendlier to complex life than the Earth.  

Totally agree. 

Quote

This discussion is a bit OT, we can discuss this further if someone wants to start another thread or we can go to my thread which is similar "super habitable planets" 

Perhaps...but as I suggested earlier somewhere, it wasn't really so long ago that the Earth was not only the center of the galaxy, the MW galaxy was the only galaxy, and was the center of the Universe. We have come a long way since those days of course, and the continuing discoveries of all sorts of extra solar planets, around a myriad of different stars, points to the scientifically support edict, that the Earth, [other then being the only place we positively know of supporting life] is nothing special at all. I do believe though that discussing extra solar planets, particularly the ever increasing numbers of verified candidates, that ETL is bound to be raised. I also totally agree with your other summation re the eventual discovery of life off this Earth within our own system, as also it appears do many cosmologists in this day and age. When that does happen, I would venture to say that it will raise the question of Panspermia, of which I sort of lean to...but that also is the subject of another thread.

[Strange]

On 07/01/2018 at 12:24 AM, Raider5678 said:

So yes, unique, however probably not the only one.

This is obviously some strange usage of the word 'unique' that I wasn't previously aware of. (To paraphrase Arthur Dent.)

 

[Raider5678]

2 minutes ago, Strange said:

This is obviously some strange usage of the word 'unique' that I wasn't previously aware of. (To paraphrase Arthur Dent.)

 

Same way some people consider diamonds are a unique jewel(Yes, I know they're a lot more common then people think, it's an example of the strange usage)

[Silvestru]

40 minutes ago, Raider5678 said:

Same way some people consider diamonds are a unique jewel(Yes, I know they're a lot more common then people think, it's an example of the strange usage)

*than

I never heard the expression that the diamond is an unique jewel. Octuplets are also rare but they are less unique than me haha. (I'm a single child)

[Raider5678]

3 minutes ago, Silvestru said:

*than

I never heard the expression that the diamond is an unique jewel. Octuplets are also rare but they are less unique than me haha. (I'm a single child)

Grammar Nazi.

Kidding. 

 

You've never heard that? Diamonds are unique, Diamonds are forever, etc?

[Silvestru]

1 minute ago, Raider5678 said:

Grammar Nazi.

Kidding. 

 

You've never heard that? Diamonds are unique, Diamonds are forever, etc?

I have but I thought it refers to their shape as unique from other diamonds. Like each snowflake was assumed to have a unique shape.

Quote

Snowflakes form in a wide variety of intricate shapes, leading to the notion that "no two are alike". Although nearly-identical snowflakes can exist, they are very unlikely to be found in nature.

 

[Raider5678]

2 minutes ago, Silvestru said:

I have but I thought it refers to their shape as unique from other diamonds. Like each snowflake was assumed to have a unique shape.

 

Fair enough.