Ongoing important Science news thread

[Snuffleupagus]

Originally Posted by polak

Why do you tease us NASA? I want to know today......



That is going to be a terrifying day.

They get one shot. Everything has to be perfect since they can't go and fix it.

Also, James Webb is infrared isn't it? Doesn't have the same "wow" factor as telescopes optimized for visible light, picture wise. Still can't wait for the potential discoveries they make though.

They just add the colour later like they do with most of the Hubble pics.

[Fuzz]

This is an X-ray image, but infrared can be treated int the same way. Because our eyes can't see these bands, you just take 3 bands of wavelength, and you assign each to the R, G, and B colour channels. It's a false colour, or psuedo colour image, but it allows you to visualize the different wavelength. The same is done with satellite images. They don't have one RGB sensor, they have several at specific wavelengths. 3 of these usually roughly correspond to our eye sensitivity, so they combine those channels back to create an RGB image, but they can also substitute in infrared bands which is useful for things like vegetation mapping.

TLDR: James Webb will still have cool images.

[JurassicTunga12]

NASA announced today that they have discovered 7 earth like planets around a nearby star which is 40 light years away. 3 of them are in the habitable zone.

more
https://www.nasa.gov/press-release/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around

http://www.popularmechanics.com/spac...ts-trappist-1/

[troutman]

a small, dim red dwarf star about 39 light-years away

TRAPPIST-1 is technically an ultracool dwarf star. This dim little star has only 8 percent of the mass of the sun, and temperatures are estimated around 2,550 Kelvin compared to 3,800 Kelvin for other red dwarfs and a scorching 5,800 Kelvin for our sun. In fact, TRAPPIST-1 is only slightly bigger than Jupiter.


Fortunately, the seven planets around TRAPPIST-1 orbit much closer to their host star than we do. Its inner planets have orbits that resemble Jupiter's Galilean moons. All seven orbit much closer to TRAPPIST-1 than even Mercury orbits the sun, allowing them to receive about the same amount of energy and heat as the Earth.

[polak]

Nasa needs to limit it's use of the word "major".

The first exoplanet discovered, yeah that's a major announcement. The first earth like exoplanet discovered, also a major announcement.

More earth like exoplanets discovered? Not "major". We already knew there were a ton of them out there.

That said, hopefully this leads to a major announcement once JWST come on line. The fact that they think they're probably tidally locked to their star is also sort of disappointing.

[Jiggy_12]

This is a good read about it, in addition to the ones above:

http://www.independent.co.uk/news/sc...-a7593941.html

[Cappy]

Originally Posted by polak

Nasa needs to limit it's use of the word "major".

The first exoplanet discovered, yeah that's a major announcement. The first earth like exoplanet discovered, also a major announcement.

More earth like exoplanets discovered? Not "major". We already knew there were a ton of them out there.

That said, hopefully this leads to a major announcement once JWST come on line. The fact that they think they're probably tidally locked to their star is also sort of disappointing.

Build the hype - more funding?

[para transit fellow]

Originally Posted by troutman

a small, dim red dwarf star about 39 light-years away

Off -topic observation:
The same description might also apply to certain politicians ...

[octothorp]

Originally Posted by octothorp

So this seems super-interesting and significant as a potential extra-terrestrial life target: The structure of that solar system is more like a gas-giant/moon relationship like Jupiter and its moons. If the system is really planet-rich and they have orbital resonance relationships with each other, that means they could have tides, and this could also help keep the planets internally molten, and thus have protective magnetic fields.

Yes! Orbital resonance confirmed:

These orbital interactions may have been key to stabilizing the TRAPPIST-1 system. The ratios of the time it takes for neighboring planets to orbit are all ratios of integers: 8/5, 5/3, 3/2, 3/2, and 4/3. Integer ratios provide interactions that help prevent the sort of planetary chaos that can launch planets out of the exosolar system or send them spinning into the host star. When we see resonances like this, it's taken as a sign that the planets formed farther from their host star and migrated inward due to friction from the disk of material they formed within. Orbital resonances check this inward migration and produce tightly packed systems like TRAPPIST-1.

Not only are some of them big enough to potentially have sustained plate tectonics, but their close proximity may allow gravitational stresses to warm their interiors through tidal forces, much as happens with Jupiter's large moons. So, there's a chance that these planets are being heated both from within and without. Active geology can also have a large influence on the composition of a planet's atmosphere.

From ars-technica
https://arstechnica.com/science/2017...abitable-zone/

[jayswin]

How long would it take us to travel 39 light years?

[Mr.Coffee]

By my calculations, if the velocity was the speed of light...

[Fuzz]

39 years at the speed of light. Our fastest current probe will reach approximately 0.067% the speed of light. So, uhm, about 58 000 years. Give or take.

[ken0042]

Yes, at the speed of light (300,000 km per second) we would get there in 39 years.

However going at 200,000 km/h or 55 km per second; which is at least twice as fast as any spacecraft we have out there now, it would take 210,000 years.

[Knut]

Originally Posted by ken0042

Yes, at the speed of light (300,000 km per second) we would get there in 39 years.

However going at 200,000 km/h or 55 km per second; which is at least twice as fast as any spacecraft we have out there now, it would take 210,000 years.

Not to mention the time needed to accelerate and then decelerate. Unless you want to just blow right by the solar system

[polak]

Originally Posted by octothorp

Yes! Orbital resonance confirmed:




From ars-technica
https://arstechnica.com/science/2017...abitable-zone/

Does that matter if they're tidally locked with the star?

[octothorp]

Is there any theoretical limit to how accurate an optical telescope could be? We've already reached diminishing returns in terms of what it's practical to build and there will be better ways to get an idea of what these planets are like, but is there anything about the behaviour of light itself that makes it impossible to, say, take an accurate photo of the surface of a planet 39 light years away?

edit: nevermind, found an answer. Still don't exactly understand the answer.

http://astronomy.stackexchange.com/q...pes-resolution

[polak]

Originally Posted by ken0042

Yes, at the speed of light (300,000 km per second) we would get there in 39 years.

However going at 200,000 km/h or 55 km per second; which is at least twice as fast as any spacecraft we have out there now, it would take 210,000 years.

Starshot would get to roughly 20% speed of light.

[octothorp]

Originally Posted by polak

Does that matter if they're tidally locked with the star?

Yeah, absolutely... If you've got a tidally locked planet with one side facing the star all the time, then tides could distribute that heat and avoid the extreme regions of hot and cold that a planet like Mercury has. The star heats one side of the planet, but the tides caused by orbital resonance from other planets would distribute temperature throughout the ocean... not entirely equally, but potentially enough to create habitable zones.

Tidal locking would result in no day/night cycle obviously, but it's questionable how important that is to life and evolution, as long as there's something else moderating the temperature.

There are two biomes on earth that may have been crucial for evolution on earth: one is the inter-tidal region; the other is hydrothermal vents. One needs tides, obviously. The other needs an active molten core. Orbital resonance can produce both these things.

In the case of Europa, for example, the orbital resonance with Ganymede and Io allow it to maintain a slightly elliptical orbit, despite the fact that it is tidally locked with Jupiter. This elliptical orbit causes tidal flexing that keeps the core of the moon liquid.

[Sluggo]

Originally Posted by octothorp

Yeah, absolutely... If you've got a tidally locked planet with one side facing the star all the time, then tides could distribute that heat and avoid the extreme regions of hot and cold that a planet like Mercury has. The star heats one side of the planet, but the tides caused by orbital resonance from other planets would distribute temperature throughout the ocean... not entirely equally, but potentially enough to create habitable zones.

The issue is that M class stars tend to be active in their early life and they would tend to break apart water atoms and blow them off with the solar wind into space leaving their planets in a state similar to the moon Io or the planet Venus. The only hope is this solar system is older so the planets have a higher level of Iron to form strong magnetic fields to prevent this stellar water erosion.

All these planets are likely to be tidally locked with their host star so they would have to develop another means of generating a strong magnetic field unlike the Earth and the outer planets of our solar system.

[troutman]

The transit method used to detect the planets. How confident can we be in the results when it seems so hard to measure and rule out other effects?

http://www.blastr.com/2017-2-22/exop...ng-nearby-star