NASA has discovered 7 Earth-like planets orbiting a star

originally posted by: InachMarbank

originally posted by: muSSang
a reply to: InachMarbank

How can you detect oxygen (or other atmospheric elements) trillions of miles away?

The can do this almost the same way they detect how a planet is there, when the planet passes the sun the light spectrum changes depending on the planets atmosphere. Its amazing how far we have come in 20 years.

Now, different elements absorb light, rather than allowing it to pass through, but they only absorb certain parts of the light spectrum. This generates a “light signature”.

And its remarkably simple.

If we were to look at a light spectrum coming from Earth, for example, the “barcode” would be missing the frequencies that correlate to nitrogen, oxygen and argon would be missing, as those compose Earth’s atmosphere (78%, 21% and 1%, respectively).

This link helps with blue red shift and explains how they can tell the chemical composition

Thanks for that explanation.
Do you know the magnification power of the TRAPPIST telescopes?

The TRAPPIST telescope that was used to originally discover the first three of these planets (TRAPPIST-1B, 1c, and 1d) about a year ago is a relatively small 0.6 meter telescope with a 4.8 meter focal length.

However, the magnification power of the telescope need not be that great in order to find planets using the Transiting method. They never really need to "see" the planet to gather the very strong evidence that they are there. In fact, I don't think any of the TRAPPIST-1 planets have been directly observed yet.

Over the past year since the discovery of the first three planets orbiting TRAPPIST-1, other telescopes have been used to help learn more details about these worlds (the details mentioned in the recent NASA press conference), and more hade been discovered by NASA's 0.85 meter diameter; 10.2 meter focal length Spitzer Space telescope (TRAPPIST 1e, 1f, 1g, and 1h). Spitzer also used the transiting method to discover these worlds.

Other telescopes around the world (some large, some small) have been used for other detailed observations of these planets.

I wonder if the VLT (Very Large Telescope) could be used to find and study exoplanets. After all, its mirrors are 8 meter in diameter each, about 4 times as large as the Hubble's. And trust me, when it comes to astronomy, the mirror size (and, thus, the resolving power) is more important than the magnification power.

Zero evidence of life outside Earth. None.


That is all.

originally posted by: Tempter
Zero evidence of life outside Earth. None.


That is all.

True, but given the size and scope of the universe, and given what we know about the ability for extremophile life on earth to find a way even in what seems to be the harshest conditions for that life, I'd say that life almost surely exists elsewhere in the universe.

Granted, until that ET life is actually found, science cannot say that it 100% exists, but I think science in general is at least 99% convinced that life elsewhere probably exists.

I mean, think of the alternative: The Earth is just an infinitesimal speck of near nothingness compared to the known and/or observable universe; it would seem highly unlikely that we are so special that life only exists here. Life might be rare, but given the size of the known universe, even rare life would exist in a lot of places in that universe.

originally posted by: wildespace
I wonder if the VLT (Very Large Telescope) could be used to find and study exoplanets. After all, its mirrors are 8 meter in diameter each, about 4 times as large as the Hubble's. And trust me, when it comes to astronomy, the mirror size (and, thus, the resolving power) is more important than the magnification power.

The VLT was used to study (and I think helped confirm the existence of) at least some of the seven known TRAPPIST-1 planets. However, I think the official "discoveries" of those planets is credited to the TRAPPIST telescope and Spitzer.

a reply to: InachMarbank

I would have to read the articles again, but if it can pick the light distortions up it should be able to have a sneak peak of the atmospheric compositions.

a reply to: TrueBrit

Thank you for clarifying and I definitely agree that we should stay on topic (sorry for the potential side track).

Nonetheless, I'm staying tuned for more information.

a reply to: muSSang

THIS, my friends, IS progress.
Reminds me of men in black when Kay is talking to jay on the bench.

Kay: "A person is smart. People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow."

People said we would never find planets that we were it.
We showed them huh.

I'm not an expert at this by any means, so a question is floating around in my mind for quite some time now. Isn't it possible with one of those telescopes to look for light sources on other planets, especially the earth-like ones? I remember the "universe" picture taken by the Hubble telescope, which shows a tiny speck of the observable universe with hundreds of Galaxys being visible, but no detailed pictures of planets' surfaces in our relative neighborhood.
I guess it's just a question to make the picture sharper, maybe some configurations to one of the telescopes would make it possible.

originally posted by: kiliker30
a reply to: muSSang

THIS, my friends, IS progress.
Reminds me of men in black when Kay is talking to jay on the bench.

Kay: "A person is smart. People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow."

People said we would never find planets that we were it.
We showed them huh.

Well, nobody ever really said (at least not in the past several decades of science -- or maybe even in the past century of science) that "we were it". Granted, science a few decades ago could not conceive how we would be able to detect planets around other stars, but it is false to say that science had said that there WERE no other planets around other stars, and the "we were it".

If you asked a typical astronomer in the 1950s, or even the 1930s, whether other planets existed around other stars, her or she most likely would have responded "Planets around other stars almost surely do exist".


For that matter, it is also false to say that people thought the Earth was flat until 500 years ago. It may be true that a typical uneducated person 500 years ago may have assumed the earth was flat (if they ever even thought about it), but the idea that it is a spheroid had been known to science since the ancient Greeks showed that it was 2500 years ago, and most science-minded people since that time agreed.

originally posted by: BenSisko
I'm not an expert at this by any means, so a question is floating around in my mind for quite some time now. Isn't it possible with one of those telescopes to look for light sources on other planets, especially the earth-like ones? I remember the "universe" picture taken by the Hubble telescope, which shows a tiny speck of the observable universe with hundreds of Galaxys being visible, but no detailed pictures of planets' surfaces in our relative neighborhood.
I guess it's just a question to make the picture sharper, maybe some configurations to one of the telescopes would make it possible.

It is more about brightness.

As bright as the light of big cities might seem, currently Earth's night side is roughly 600,000 times dimmer than its day side. Existing telescopes could only see the night side of a world like Earth out to a distance of a little more than 1,000 astronomical units — that is, the edge of the solar system. "The closest star is 100 times farther than that," Loeb said. To see nighttime city lights as bright as Earth's on a world in the habitable zone of the closest star, you would need a telescope with optics at least 100 times wider in diameter than the Hubble Space Telescope's, he added.

Source www.space.com...

I wasn't too hyped on this "major NASA announcement" but the find is still cool. Their orbits are rather neat...

Daniel Tamayo noticed something else. The clockwork of the TRAPPIST-1 system is the most complex case yet of what astrophysicists call a resonant chain, where the “years” of each orbiting body relate to one another as simple ratios. For every eight times the innermost world races through its day-and-a-half-long orbit, the next planet goes around roughly five times, the next one after that orbits three times, and the next one two times. And so on.

While Tamayo was working on his simulations, he was approached by Matt Russo, a fellow postdoc and jazz guitarist who thought the TRAPPIST-1 resonances looked familiar from music theory.

Why not?! Musical notes are just ratios. An octave being a resonance at half the frequency. So guess what they did?

The seventh planet, h, orbits about once every three weeks. Sped up some 200 million times and expressed in sound waves, that frequency is a C note. From there, the known ratios between planets determine every other planet’s signature note. Together the notes form a major ninth chord [!!!]. “It’s really remarkable that it worked out like that,” Russo said. “Even with a different pattern of resonances, you wouldn’t get a chord that sounds as good.”

QuantaMagazine.org, May 10, 2017 - Exoplanet Puzzle Cracked by Jazz Musicians

Is that crazy or what?!! A Maj-9 chord! Music of the spheres indeed!

They confirmed that the planet, TRAPPIST-1h, orbits its star every 18.77 days, is linked in its orbital path to its siblings and is frigidly cold. Far from its host star, the planet is likely uninhabit-able—but it may not always have been so.
...

"Resonances can be tricky to understand, especially between three bodies. But there are simpler cases that are easier to explain," Luger said. For instance, closer to home, Jupiter's moons Io, Europa and Ganymede are set in a 1:2:4 resonance, meaning that Europa's orbital period is exactly twice that of Io, and Ganymede's is exactly twice that of Europa.

These relationships, Luger said, suggested that by studying the orbital velocities of its neighbor planets they could predict the exact orbital velocity, and hence also orbital period, of TRAPPIST-1h even before the K2 observations. Their theory proved correct when they located the planet in the K2 data.

TRAPPIST-1's seven-planet chain of resonances established a record among known planetary systems, the previous holders being the systems Kepler-80 and Kepler-223, each with four resonant planets. The resonances are "self-correcting," Luger said, such that if one planet were to somehow be nudged off course, it would lock right back into resonance. "Once you're caught into this kind of stable resonance, it's hard to escape," he said.

phys.org - Kepler telescope spies details of TRAPPIST-1 system's outermost planet.

A bit more info on the orbital relationships among the 7 planets. It is neat that they predicted the orbit period before they observed. Because they knew the others and the orbits are in resonance they nailed the orbit spot on. That even caught them a bit off since they said they never nail something 100%.

Amazing news!