• We have updated the guidelines regarding posting political content: please see the stickied thread on Website Issues.

Exoplanets (Extra-Solar Planets)

This page has very nice NASA images of what they think the planets may look like.
http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21422
640px-PIA21422_-_TRAPPIST-1_Planet_Lineup%2C_Figure_1.jpg

This artist's concept shows what the TRAPPIST-1 planetary system may look like, based on available data about the planets' diameters, masses and distances from the host star. The system has been revealed through observations from NASA's Spitzer Space Telescope and the ground-based TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) telescope, as well as other ground-based observatories. The system was named for the TRAPPIST telescope.
The seven planets of TRAPPIST-1 are all Earth-sized and terrestrial, according to research published in 2017 in the journal Nature. TRAPPIST-1 is an ultra-cool dwarf star in the constellation Aquarius, and its planets orbit very close to it.
They are likely all tidally locked, meaning the same face of the planet is always pointed at the star, as the same side of our moon is always pointed at Earth. This creates a perpetual night side and perpetual day side on each planet.
TRAPPIST-1b and c receive the most light from the star and would be the warmest. TRAPPIST-1e, f and g all orbit in the habitable zone, the area where liquid water is most likely to be detected. But any of the planets could potentially harbor liquid water, depending on their compositions.
In the imagined planets shown here, TRAPPIST-1b is shown as a larger analogue to Jupiter's moon Io. TRAPPIST-1d is depicted with a narrow band of water near the terminator, the divide between a hot, dry day and an ice-covered night side. TRAPPIST-1e and TRAPPIST-1f are both shown covered in water, but with progressively larger ice caps on the night side. TRAPPIST-1g is portrayed with an atmosphere like Neptune's, although it is still a rocky world. TRAPPIST-1h, the farthest from the star, would be the coldest. It is portrayed here as an icy world, similar to Jupiter's moon Europa, but the least is known about it.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech, also in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.
For more information about the Spitzer mission, visit http://www.nasa.gov/spitzer and http://spitzer.caltech.edu.
I particularly like the images of TRAPPIST-1d and TRAPPIST-1f. A dry, hot tidally-locked world and an eyeball-Earth. The one image I disagree with is TRAPPIST-1g; that world is shown as a mini-Neptune, but there is a good chance that TRAPPIST-1g is the most Earth-like of the lot. Instead of having a dense atmosphere, it may have lost a significant amount due to flaring from the star; it should also be heated tidally by the proximity of so many other planets. So it could be warm, with a relatively thin atmosphere, and could be rotating due to spin-resonance. Probably not very Earth-like.
 
More greatness from PBS spacetime.

Apparently the Trappist planets are so close together that if you were on one, the other planets would be huge in the sky at closest approach, big enough to see continents on them.

 
That leads me to believe that a likelihood of life on at least one planet is quite high.
One of the reasons why we have life at all on this planet is because we have a large moon in close proximity to the planet, acting as a shield and stirring up the Earth's core.
 
More greatness from PBS spacetime.

Apparently the Trappist planets are so close together that if you were on one, the other planets would be huge in the sky at closest approach, big enough to see continents on them.


Makes our solar system look boring in comparison.
 
Fire Trap
Flytrap
Rattletrap
Booby Trap
Death Trap
Honey Trap
Mouse Trap
 
Atmosphere found around Earth-like planet GJ 1132b
By Rebecca MorelleScience Correspondent, BBC News

_86638779_screenshot2015-11-11at18.22.11.png
Image copyrightDANA BERRY
Image captionArtist's impression of GJ 1132b: The planet's thick atmosphere may contain water or methane
Scientists say they have detected an atmosphere around an Earth-like planet for the first time.

They have studied a world known as GJ 1132b, which is 1.4-times the size of our planet and lies 39 light years away.

Their observations suggest that the "super-Earth" is cloaked in a thick layer of gasses that are either water or methane or a mixture of both.

The study is published in the Astronomical Journal.

Discovering an atmosphere, and characterising it, is an important step forward in the hunt for life beyond our Solar System.

But it is highly unlikely that this world is habitable: it has a surface temperature of 370C.

Dr John Southworth, the lead researcher from Keele University, said: "To my knowledge the hottest temperature that life has been able to survive on Earth is 120C and that's far cooler than this planet."

Chemical signatures

The discovery of planet GJ 1132b was first announced in 2015. It lies in the Vela constellation in the southern hemisphere.

One possibility is that it is a 'water world' with an atmosphere of hot steam
While it is a similar size to Earth, the star it orbits is much smaller, cooler and dimmer than our Sun.

Using a telescope at the European Southern Observatory in Chile, the researchers were able to study the planet by watching how it blocked some of the light of its host star as it passed in front of it.

"It makes the star look a little bit fainter - and it's actually a very good way of finding transiting planets - it's how this one was found," said Dr Southworth.

But different molecules in a planet's atmosphere - if it has one - absorb light in different ways, allowing scientists to look for their chemical signatures when the world transits its star.

The observations of planet GJ 1132b suggest that it has a thick atmosphere containing either steam and/or methane.

"One possibility is that it is a 'water world' with an atmosphere of hot steam," said Dr Southworth.

The researchers say while it is unlikely that any life-forms could survive on this world, the discovery of an atmosphere is encouraging in the hunt for extraterrestrial life.

Dr Southworth said: "What we have shown is that planets around low mass stars can have atmospheres and because there are so many of those in the Universe, it makes it that much more likely that one might have life."

Commenting on the research Marek Kukula, the public astronomer at the Royal Observatory Greenwich, said: "This is a nice proof of concept.

"If the technology can detect an atmosphere today, then it bodes well for being able to detect and study the atmospheres of even more Earth-like planets in the not-too-distant future."

http://www.bbc.co.uk/news/science-environment-39521344
 
Planet is 'hotter than most stars'

  • _96363515_whatsubject.jpg
    Image copyrightNASA/JPL-CALTECH
Image captionArtwork: The planet, named KELT-9b, orbits its star about 650 light-years from us
Scientists have found a hellish world where the "surface" of the planet is over 4,000C - almost as hot as our Sun.

In part, that’s because KELT-9b’s host star is itself very hot, but also because this alien world resides so close to the furnace.

KELT-9b takes just two days to complete one orbit of the star.

Being so close means the planet cannot exist for very long - the gases in its atmosphere are being blasted with radiation and lost to space.

Researchers say it may look a little like a comet as it circles the star from pole to pole - another strange aspect of this discovery.

News of KELT-9b is reported in the journal Nature. Its highly unusual properties were also presented on Monday to the spring meeting of the American Astronomical Society in Austin, Texas.

"We found [KELT-9b] back in 2014, if you can believe it; and it took us this long to finally convince ourselves that this truly bizarre and unusual world was in fact a planet orbiting another star," Prof Scott Gaudi, from The Ohio State University, told BBC News.

"We know pretty well how big the planet is and how massive it is: it's about three times the mass of Jupiter and twice as big as Jupiter.

"We know the parent star's properties reasonably well: it's about two and a half times more massive than the Sun; it's almost twice as hot as the Sun; and it's rotating very rapidly and so it would appear very flattened to our eyes."

'Hot dinner'
The planet is tidally locked to its star, meaning it always presents the same face - just as our Moon never shows its far side to Earth.

This raises the temperature on the "day side" of KELT-9b to over 4,300C - hotter than the surface of the average Red Dwarf star, by far the most common type of star in the Milky Way.

The host star - known by the simple designation of KELT-9 - is radiating so much ultraviolet light that it may completely erode the planet's atmosphere.

Prof Gaudi's team calculates material is being lost at a current rate of perhaps 10 billion or 10 trillion grams per second.

If KELT-9b possesses a rocky core, this could be laid bare eventually, but a more likely end scenario is that the planet will be engulfed by the star.

This star is what's termed an A-type object. These stars burn brilliant but brief lives. They exist for just millions of years rather than the billions of years that our Sun is expected to persist. So it may not be long before KELT-9 puffs up as it exhausts its fuel and eats the planet.

The discovery was made using a robotic telescope system that uses high-end - but standard - camera telephoto lenses attached to scientific grade detectors.

The Ohio State University operates the system at two locations, one in the northern hemisphere and one in the southern hemisphere. It is a collaboration with Vanderbilt University, Lehigh University, and the South African Astronomical Observatory.

This astronomical facility goes by the name of the Kilodegree Extremely Little Telescope. "We named the telescope kind of as a joke; we're poking a little fun at ourselves," said Prof Gaudi.

http://www.bbc.co.uk/news/science-environment-40171936
 
Signal may be from first 'exomoon'
By Paul Rincon Science editor, BBC News website

Astronomers have discovered an object that could be the first known moon located beyond the Solar System.
If genuine, the "exomoon" is likely to be about the size and mass of Neptune, and circles a planet the size of Jupiter but with 10 times the mass.

The signal was detected by Nasa's Kepler Space Telescope; astronomers now plan to carry out follow-up observations with Hubble in October.
A paper about the candidate object is published on the Arxiv pre-print site.

To date, astronomers have discovered more than 3,000 exoplanets - worlds orbiting stars other than the Sun.
A hunt for exomoons - objects in orbit around those distant planets - has proceeded in parallel. But so far, these extrasolar satellites have lingered at the limits of detection with current techniques.

Dr David Kipping, assistant professor of astronomy at Columbia University in New York, says he has spent "most of his adult life" looking for exomoons.
For the time being, however, he urged caution, saying: "We would merely describe it at this point as something
consistent with a moon, but, who knows, it could be something else."

etc...

http://www.bbc.co.uk/news/science-environment-40741545
 
Signal may be from first 'exomoon'
...

The phrasing of this title will undoubtedly spawn a host of speculative follow-ons and citations from the tinfoil hat contingent ... :headbang:

As one would reasonably expect, this phrasing is grossly misleading at face value. I have to override my initial reaction ("bitch-slap the dumb-ass journalist") because the centrally deceptive term 'signal' is actually prominent in the cited paper:

https://arxiv.org/pdf/1707.08563.pdf

The term 'signal' appearing in the scientific article refers to a significant discrete cue or potential signature discernible in the data being analyzed - not a 'signal' in the sense of some transmission from the extrasolar location being studied.

:doh::roll:
 
Yeah. My first thought was 'signal?' - poor journalism.
 
It'll probably something that will excite scientists immensely but the ordinary bloke in the street will go "Huh? I thought it was going to be aliens."
 
What the NASA press conference was about

Artificial Intelligence, NASA Data Used to Discover Eighth Planet Circling Distant Star

With the discovery of an eighth planet, the Kepler-90 system is the first to tie with our solar system in number of planets.
Credits: NASA/Wendy Stenzel
Our solar system now is tied for most number of planets around a single star, with the recent discovery of an eighth planet circling Kepler-90, a Sun-like star 2,545 light-years from Earth. The planet was discovered in data from NASA’s Kepler Space Telescope.



The newly-discovered Kepler-90i – a sizzling hot, rocky planet that orbits its star once every 14.4 days – was found using machine learning from Google. Machine learning is an approach to artificial intelligence in which computers “learn.” In this case, computers learned to identify planets by finding in Kepler data instances where the telescope recorded signals from planets beyond our solar system, known as exoplanets.
etc

https://www.nasa.gov/press-release/...-discover-eighth-planet-circling-distant-star
 
NASA-Backed Project Lays Out the Science of Detecting Alien Life
Ryan Whitwam on June 27, 2018 at 9:15 am
  • 10 Comments

    There are still many unanswered questions about the existence of extraterrestrial life. Maybe the universe is teeming with intelligent beings, or there might just be some pond scum on some out-of-the-way moon. It’s even possible there is no other life. An international team of scientists has laid the groundwork for scanning the skies for life. With the support of NASA, the researchers have simultaneously published six studies that explain how we will search exoplanets for signs of life using current and near-future technologies.

    All six studies are part of the Nexus for Exoplanet Systems Science (NExSS) program. It’s all backed by NASA, but includes teams from all over the world, tracing back to a brainstorming session held in Seattle in 2016. After two years of work, teams from the University of Washington, the University of California-Riverside, the Tokyo Institute of Technology, and others have published their research.

    This collection of studies outlines what we know about detecting life in another solar system, as well as how we can go about it. The overarching theme of the individual studies is that scientists of multiple disciplines will need to work together to find evidence of life. The first paper, from NASA’s Goddard Institute, details the best signal types to use for detecting life. It calls out atmospheric gases like oxygen and methane in particular. Light reflected by life could also be a useful signal — for example, the color of plant life across a planet’s temperate zone. Another paper from the University of California-Riverside explores what we know about life on Earth can tell us about the signals we might detect on other planets.

    More at https://www.extremetech.com/extreme...-lays-out-the-science-of-detecting-alien-life
 
What a cute baby

First confirmed image of a newborn planet revealed
Nascent planet seen carving a path through the disc of gas and dust surrounding the very young star PDS70

Nicola Davis

@NicolaKSDavis
Mon 2 Jul 2018 12.43 BSTFirst published on Mon 2 Jul 2018 11.01 BST




This image from the European Southern Observatory’s Very Large Telescope is the first clear image of a planet caught in the act of formation. Photograph: ESO/A Müller et al
It is a moment of birth that has previously proved elusive, but astronomers say they now have the first confirmed image of the formation of a planet.

The startling snapshot shows a bright blob – the nascent planet – travelling through the dust and gas surrounding a young star, known as PDS70, thought to be about 370 light years from Earth.

The black circle in the centre of the image, to the left of the planet, is a filter to block the light from the star, enabling other features of the system to be seen.

Captured by the Sphere instrument of the European Southern Observatory’s Very Large Telescope, the planet – a gas giant with a mass greater than Jupiter – is about as far from its star as Uranus is from our sun, with further analyses revealing that it appears to have a cloudy atmosphere and a surface temperature of 1000C.

etc

https://www.theguardian.com/science...rmed-image-of-a-newborn-planet-revealed-pds70
 
ultra-hot planet so hot its air contains vaporised metal

New observations of the hottest known planet have revealed temperatures similar to those typically seen at the surface of a star, as well as an atmosphere of vaporised iron and titanium.

The planet, called Kelt-9b, was discovered last year by an American team. It is in orbit about a star 650 light years from Earth in the constellation of Cygnus, the swan. The ultra hot planet is about 30 times closer to its host star than the Earth is to the sun – and its star is also twice as hot as the sun. As a result, temperatures on Kelt-9b reach 4,000C on the side that faces the star. This is not as hot as our Sun, which is almost 6,000C, but hotter than many stars.

Detailed measurements of the orbit suggest the planet is gaseous, probably mostly hydrogen and possibly with a small solid core.

Due to its proximity to the star, the planet orbits the star every 36 hours, with the same side always facing inwards. This means there is constant daytime on one side and constant night on the other, creating extreme temperature variations across the planet. The temperature of the night side is probably still about 2,000C, though, Heng suggested.

The team used the Galileo National Telescope in La Palma, Canary Islands, to observe the planet precisely as it was moving in front of its host star. By detecting the tiny fraction of light from the star that filters through the planet’s atmosphere, the astronomers were able to detect components in the atmosphere and show that these included iron vapour and titanium. This is the first time that metals have been spotted on planets beyond the solar system.
 
Here's Andrew LePage's Habitability Reality Check for this planet. Note that this planet was found more than a year ago, so it's not exactly news.
https://www.drewexmachina.com/2017/11/16/habitable-planet-reality-check-the-nearby-ross-128/

A stellar flux 1.38 times as great as that received on Earth, all falling on a single face of a tidally-locked world? This world is unlikely to be Earth-like, but if life has evolved there, the homeostasis effect of a biosphere might preserve its habitability. I doubt that life on such a world would resemble Earth life very much- too many environmental differences.
 
Here's Andrew LePage's Habitability Reality Check for this planet. Note that this planet was found more than a year ago, so it's not exactly news.
https://www.drewexmachina.com/2017/11/16/habitable-planet-reality-check-the-nearby-ross-128/

A stellar flux 1.38 times as great as that received on Earth, all falling on a single face of a tidally-locked world? This world is unlikely to be Earth-like, but if life has evolved there, the homeostasis effect of a biosphere might preserve its habitability. I doubt that life on such a world would resemble Earth life very much- too many environmental differences.
It'd have to have a moon like ours for life to evolve and survive.
 
Unfortunately, tidally-locked planets can't have moons (not for long, anyway). So that's another environmental difference.
 
Back
Top