The have found another Goldilocks world!

[Watermelon]

First, thanks for overlooking the arithmetic error.

It's 0.683 years to c/√2 at 1 g.

And no, tearing and blasting are fundamentally different. A collision at those speeds is effectively a nuclear blast. No tearing involved. The extraordinary tidal forces from near approach to a black hole would rip an object apart. No blasting involved.

What about that bending space and making it closer idea? Is that still a thing? This journey sounds a bit dangerous for me.

[JimL]

What about that bending space and making it closer idea? Is that still a thing? This journey sounds a bit dangerous for me.

It's not a thing, at least not now, the bending of space, aka wormholes, are only theoretical at this point.

[JonathanL]

It's not a thing, at least not now, the bending of space, aka wormholes, are only theoretical at this point.

Well, so is traveling at near lightspeed.

[Sparko]

Traveling, shreds, and you're confusing light speed with falling into a black hole. Accounting for relativistic effects, anything traveling at c/√2 would take as many years to arrive as there are light years to travel.

1.367 years at 1g.

How do you figure? The faster the light sail moves the more relative mass it gains meaning the less the laser can push it (not even counting the power of the laser weakening as distance grows.)

[QuantaFille]

Light speed lag would quickly make conversation pretty boring, but communication shouldn't be an issue. We regularly gather data from stars moving away from us at those speeds.

But how do you get a signal that travels at the speed of light, to something that is also traveling at the speed of light?

[Juvenal]

What about that bending space and making it closer idea? Is that still a thing? This journey sounds a bit dangerous for me.

Don't wear a red shirt.

[Juvenal]

How do you figure? The faster the light sail moves the more relative mass it gains meaning the less the laser can push it (not even counting the power of the laser weakening as distance grows.)

Yes, you'd have to boost power to maintain the same acceleration. Keep in mind this was a rebuttal to the idea that travel between stars would be limited to trivial speeds on the order of a few tens of thousands of miles per hour.

But how do you get a signal that travels at the speed of light, to something that is also traveling at the speed of light?

You don't.

[QuantaFille]

You don't.

I know. It can send data back, that part I understand. So I asked, how do we maintain communication with a receiver/transmitter (which means two way) and you said it shouldn't be an issue. That's what confused me. I think you think I meant, how do we collect the data. I was thinking more like, what if you need to send the probe instructions? But you'd have to make it entirely autonomous.

[Sparko]

I know. It can send data back, that part I understand. So I asked, how do we maintain communication with a receiver/transmitter (which means two way) and you said it shouldn't be an issue. That's what confused me. I think you think I meant, how do we collect the data. I was thinking more like, what if you need to send the probe instructions? But you'd have to make it entirely autonomous.

The faster the ship goes, the more time slows down for them. Any signals from them would be frequency shifted down by that amount and any messages or data from them would be that much slower. The reverse would be true for any messages sent to them. They would see the frequency as being higher, and the messages would sound more and more like chipmunks.

A ship traveling at the speed of light would experience no time at all. Their journey would be over instantly for them.

[rogue06]

Don't wear a red shirt.

[Juvenal]

Well, so is traveling at near lightspeed.

https://home.cern/science/accelerato...adron-collider

[JonathanL]

https://home.cern/science/accelerato...adron-collider

I thought that it would have been obvious that the implicit assumption in my post was that traveling at near lightspeed velocities is currently only theoretical for things such as spaceships, unmanned probes or other objects which are "suitably macro" (to make up a phrase that encompasses all objects which we are currently unable to accelerate to near-lightspeed levels.)

As you've amply demonstrated with the above reply, that was thought was incredibly stupid.

[Juvenal]

I thought that it would have been obvious that the implicit assumption in my post was that traveling at near lightspeed velocities is currently only theoretical for things such as spaceships, unmanned probes or other objects which are "suitably macro" (to make up a phrase that encompasses all objects which we are currently unable to accelerate to near-lightspeed levels.)

https://www.compoundingexpert.com/pr...ons/butt-balm/

... that was thought was incredibly stupid.

QED.

[shunyadragon]

We have found a better candidate for an earthlike world closer to ours than ever before.

Source: https://gizmodo.com/potentially-habitable-earth-sized-exoplanet-spotted-in-1842901445

Potentially Habitable Earth-Sized Exoplanet Spotted in the Kepler Reject Pile

For years, a dedicated team of experts has manually sifted through troves of rejected Kepler data in hopes of finding something the computers had missed—an exercise that has resulted in the discovery of what is now arguably the most Earth-like planet known to astronomers.

New research published yesterday in Astrophysical Journal Letters describes Kepler-1649c, a remarkably Earth-sized exoplanet located 300 light-years away. At 1.06 times the size of Earth—give or take a few decimal points—it’s practically the same size as our sparkling blue marble. This rocky planet also happens to reside within its star’s habitable zone, that sweet swatch of space within which liquid water can exist on a planet’s surface.

Incredibly, this terrestrial exoplanet might never have been discovered had it not been for a systematic visual inspection of all Kepler data rebuffed by a computer algorithm. More on that in just a sec—let’s take a closer look at this newly discovered world.

Kepler-1649c receives around 75 percent of the starlight we get on Earth, and it features an equilibrium temperature around 234 degrees Kelvin (-39 degrees Celsius, -38 degrees Fahrenheit), according to the paper. Equilibrium temperature is based exclusively on incoming stellar radiation and excludes factors such as an object’s albedo (reflectivity) and atmospheric effects. In terms of Kepler-1649c’s actual surface temperature, that cannot yet be determined because the scientists have no clue about the composition of this planet’s atmosphere, if it even has one. By comparison, however, Earth has an equilibrium temperature of 278.5 Kelvin (5 degrees C, 42 degrees F).

“In terms of size and likely temperature, this is the most similar planet to Earth that has ever been found with Kepler,” said Jeff Coughlin, a co-author of the study, in a SETI Institute press release.

Other notable exoplanets include TRAPPIST-1f, which is comparable to Earth in terms of size, while TRAPPIST-1d and TOI 700d are comparable to Earth in terms of temperature. But none of these hit both the size and temperature marks quite like Kepler-1649c.

This exoplanet requires just 19.5 days to make a complete orbit around its host star, a red dwarf known as Kepler-1649. With such a short year, it’s clear that Kepler-1649c lives in close proximity to its star. But at one-quarter the size of our Sun, this low mass star is not nearly as powerful as ours.

This is potentially bad news in terms of habitability. Red dwarfs are extremely common in the galaxy (around three of every four stars in the Milky Way is a red dwarf), but they’re prone to frequent temper tantrums in the form of powerful stellar bursts. This has led to concerns among astrobiologists that red dwarf systems are devoid of life.

To date, NASA’s Kepler Space Telescope has contributed to the discovery of nearly 2,400 exoplanets, but this particular world almost slipped through the cracks.

Several years ago, a computer algorithm called Robovetter missed this planet while parsing Kepler data. These automated systems are critically important because Kepler, which was in operation from 2009 to 2018, produced hundreds of thousands of observations over the years, all of which need to be analyzed for signs of possible exoplanets.

The first step in this automated process is for the system to use the transit method, in which it looks for dips in a star’s brightness—a possible sign of an orbiting exoplanet. The second step requires Robovetter to reject false positives caused by extraneous sources, such as variable stars (which exhibit fluctuating levels of luminosity), nearby objects passing through, and artifacts produced by Kepler’s electronics.

The system is not perfect, however.

“If we hadn’t looked over the algorithm’s work by hand, we would have missed it,” said Andrew Vanderburg, the lead author of the study and a NASA Sagan Postdoctoral Fellow at the University of Texas at Austin, in a NASA press release.

A dedicated team of experts called the Kepler False Positive Working Group looked through these rejects in hopes of finding something Robovetter might have missed. The new exoplanet was spotted in false-positive Kepler data released three years ago.

“This discovery highlights the value of human inspection of planet candidates even as automated techniques improve, and hints that terrestrial planets around... M-dwarfs may be more common than those around more massive stars,” wrote the authors in the new study.

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[shunyadragon]

Another goldilocks planet found closer an earth like than ever before. . . but there is a problem. There are likely many earth-like planets everywhere, but at what stage are they in their development of their solar system. It depends on how mature the sun is. In our solar system both Venus and Mars were potentially living earth-like planets but no more. Earth-like planets have a life span as the sun matures, and eventually earth will no longer be an earth-like planet.

Source: https://scitechdaily.com/mirror-image-of-the-earth-and-sun-discovered-3000-light-years-away/

“Mirror Image” of the Earth and Sun Discovered 3000 Light-Years Away
TOPICS:AstrobiologyAstronomyAstrophysicsExoplanetM ax Planck Institute
By MAX PLANCK SOCIETY JUNE 7, 2020

The star Kepler-160 and its companion KOI-456.04 are more reminiscent of the Sun-Earth system than any previously known exoplanet-star pair.

Among the more than 4,000 known exoplanets, KOI-456.04 is something special: less than twice the size of Earth, it orbits a Sun-like star. And it does so with a star-planet distance that could permit planetary surface temperatures conducive to life.

The object was discovered by a team led by the Max Planck Institute for Solar System Research in Göttingen. Its host star, called Kepler-160, actually emits visible light; the central stars of almost all other exoplanets, on the other hand, emit infrared radiation, are smaller and fainter than the Sun and therefore belong to the class of red dwarf stars.

Typical Exoplanets

Distant worlds: typical exoplanets orbiting around a Sun-like star are about the size of Neptune and are in close orbit (third picture from above). Almost all of the Earth-sized planets known to have potentially Earth-like surface temperatures are in orbit around red dwarf stars, which do not emit visible light but infrared radiation instead (bottom panel). The Earth is in the right distance from the Sun to have surface temperatures required for the existence of liquid water. The newly discovered planet candidate KOI-456.04 and its star Kepler-160 (second panel from above) have great similarities to Earth and Sun (top panel). Credit: MPS / René Heller

Space telescopes such as CoRoT, Kepler, and TESS have allowed scientists the discovery of about 4000 extrasolar planets (planets around distant stars) within the past 14 years. Most of these planets are the size of the gas giant planet Neptune, about four times the size of the Earth, and in relatively close orbits around their respective host stars. But scientists have also discovered some exoplanets as small as the Earth that could potentially be rocky. And a handful of these small planets are also at the right distance to their host star to potentially have moderate surface temperatures for the presence of liquid surface water – the essential ingredient for life on Earth.

“The full picture of habitability, however, involves a look at the qualities of the star too,” explains MPS scientist and lead author of the new study Dr. René Heller. So far, almost all exoplanets less than twice the size of Earth that have a potential for clement surface temperatures are in orbit around a red dwarf.

Red dwarf stars are known for their extremely long lifetimes. Life on an exoplanet in orbit around an old red dwarf star could potentially have had twice as much time than life on Earth to form and evolve. But the radiation from a red dwarf star is mostly infrared rather than visible light as we know it. Many red dwarfs are also notorious for emitting high-energy flares and for frying their planets, which would later become habitable, with enhanced stellar luminosities as long as these stars are young. Moreover, their faintness requires any habitable planet to be so close to the star that the stellar gravity starts to deform the planet substantially. The resulting tidal heating in the planet could trigger fatal global volcanism. All things combined, the habitability of planets around red dwarf stars is heavily debated in the scientific community.

In their new research article, the team of scientists from MPS, the Sonneberg Observatory, the University of Göttingen, the University of California in Santa Cruz, and from NASA now reports the discovery of a planet candidate less than twice the size of the Earth and with moderate illumination from a Sun-like star

At a distance of just over 3000 light-years from the solar system, the star Kepler-160 was located in the field of view of the Kepler primary mission and was continuously observed from 2009 to 2013. Its radius of 1.1 solar radii, its surface temperature of 5200 degrees Celsius (300 degrees less than the Sun), and its very Sun-like stellar luminosity make it an astrophysical portrayal of our own parent star.

Kepler-160 has been known for about six years to be a host star of two exoplanets, called Kepler-160b and Kepler-160c. Both of these planets are substantially bigger than Earth and in relatively close orbits around their star. Their surface temperatures would certainly make them hotter than a baking oven and everything but hospitable for life as we know it. But tiny variations in the orbital period of planet Kepler-160c gave scientists a signature of a third planet that had yet to be confirmed.

The team of German and US American scientists now returned to the archival Kepler data of Kepler-160 to search for additional planets around that star and to verify the planetary origin of the perturber of the orbit of Kepler-160c. Heller and his colleagues had previously been successful in finding a total of 18 exoplanets in old Kepler data.

When searching for exoplanets, scientists usually look for repeating brightness variations of stars. These temporary dimmings, usually just one percent or less of the apparent stellar brightness, can be caused by planets transiting the disks of their host stars as seen from Earth. The key idea of Michael Hippke, co-author of the new work, and Heller was to use a detailed physical model of the stellar brightness variation instead of searching for a step-like jump-to-dimming and then jump-back-to-normal brightness pattern in stellar light curves.

This box-like approximation used to be the standard search technique for almost two decades. “Our improvement is particularly important in the search for small, Earth-sized planets,” Heller explains. “The planetary signal is so faint that it’s almost entirely hidden in the noise of the data. Our new search mask is slightly better in separating a true exoplanetary signal from the noise in the critical cases,” Heller adds.

Their new search algorithm was crucial for the discovery of the new transiting planet candidate KOI-456.04. “Our analysis suggests that Kepler-160 is orbited not by two but by a total of four planets,” Heller summarizes the new study. One of the two planets that Heller and his colleagues found is Kepler-160d, the previously suspected planet responsible for the distorted orbit of Kepler-160c. Kepler-160d does not show any transits in the light curve of the star and so it has been confirmed indirectly.

The other planet, formally a planet candidate, is KOI-456.04, probably a transiting planet with a radius of 1.9 Earth radii and an orbital period of 378 days. Given its Sun-like host star, the very Earth-like orbital period results in a very Earth-like insolation from the star – both in terms of the amount of the light received and in terms of the light color. Light from Kepler-160 is visible light very much like sunlight. All things considered, KOI-456.04 sits in a region of the stellar habitable zone – the distance range around a star admitting liquid surface water on an Earth-like planet – that is comparable to the Earth’s position around the Sun.

“KOI-456.01 is relatively large compared to many other planets that are considered potentially habitable. But it’s the combination of this less-than-double the size of the Earth planet and its solar type host star that make it so special and familiar,” Heller clarifies. As a consequence, the surface conditions on KOI-456.04 could be similar to those known on Earth, provided its atmosphere is not too massive and non-Earth-like. The amount of light received from its host star is about 93 percent of the sunlight received on Earth. If KOI-456.04 has a mostly inert atmosphere with a mild Earth-like greenhouse effect, then its surface temperature would be +5 degrees Celsius on average, which is about ten degrees lower than the Earth’s mean global temperature.

It cannot currently be ruled out completely that KOI-456.04 is in fact a statistical fluke or a systematic measurement error instead of a genuine planet. The team estimates the chances of a planetary nature of KOI-456.04 to be about 85% pro planet. Obtaining a formal planetary status requires 99%. While some of the Earth’s most powerful ground-based telescopes might be able to validate this candidate with observations of one of its upcoming transits, there is also a good chance that the PLATO space mission of ESA will be capable of a confirmation. PLATO is scheduled for launch in 2026 and one of its major science goals is the discovery of Earth-sized planets around Sun-like stars. The MPS is currently building the PLATO Data Center and deeply involved in the PLATO mission. If PLATO will be oriented in such a way as to re-observe the field of view of the Kepler primary mission, then KOI-456.04 will have a chance of being confirmed and studied in even more detail with PLATO.

Reference: “Transit least-squares survey: III. A 1.9 R⊕ transit candidate in the habitable zone of Kepler-160 and a nontransiting planet characterized by transit-timing variations” by René Heller, Michael Hippke, Jantje Freudenthal, Kai Rodenbeck, Natalie M. Batalha and Steve Bryson, 4 June 2020, Astronomy & Astrophysics.
DOI: 10.1051/0004-6361/201936929.

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