Beijing: Chinese scientists have proposed a space project to survey the sky through a space-borne telescope to hunt for habitable Earth-like planets outside our solar system, about 32 light-years from Earth.If the project, named Closeby Habitable Exoplanet Survey (CHES), could be carried out, it will be the first space mission specially designed to search for habitable terrestrial planets around the nearby Sun-like stars, Xinhua news agency reported.According to the project, a 1.2-metre-aperture optical telescope with high image quality, high stability, and low distortion will be placed into a Halo orbit at the second Lagrangian (L2) point of the Sun-Earth system and maintain a stable operation period of at least five years in that orbit.The telescope will explore approximately 100 Sun-like stars, with each of them being observed at least 50 times.The Halo orbit at the Sun-Earth L2 point is less affected by Earth's gravity, and the thermal radiation environment is relatively stable. The satellite can work for a long time with little fuel consumption, which is very suitable for astronomical satellites to conduct continuous observation, the report said.The exploration of habitable planets outside the solar system is one of the key frontiers of fundamental research in astronomy. It will offer crucial clues to the issues such as "Are we alone in the universe?" and "How can planets become the cradle of life?" according to Ji Jianghui, a research professor from the Purple Mountain Observatory of the Chinese Academy of Sciences, who is the principal investigator of the CHES mission.He said more than 5,000 exoplanets have been discovered and confirmed so far, including about 50 Earth-like planets in the habitable zone, but most of them are hundreds of light-years away from Earth."The discovery of the nearby habitable worlds will be a great breakthrough for humankind, and will also help humans visit those Earth twins and expand our living space in the future," Ji said.The CHES will observe about 100 Sun-like stars 32 light-years away on a long-term survey, and will hopefully discover roughly 50 Earth-like planets or super-Earths, planets that are up to about 10 times the mass of Earth, in habitable zones around nearby Sun-like stars, especially planets that have similarities in size, orbit and habitability to Earth.The CHES will conduct an extensive survey on the number, true planetary masses and three-dimensional orbits of those habitable planets, Ji added.Based on the space-borne ultra-high-precision relative astrometry, the CHES will precisely measure the micro-arcsecond-level angular separation of a target star relative to six to eight standard reference stars.This subtle change can be used to calculate the very tiny wobble of the target star caused by its revolving planet's gravitational perturbations and detect those terrestrial planets in the habitable zone with real masses, the report said. —IANS

Chinese scientists have proposed a space project to survey the sky through a space-borne telescope to hunt for habitable Earth-like planets outside our solar system, about 32 light-years from Earth.

China Proposes Search For Nearby Habitable Planets Via Space Telescope

Tel Aviv (The Hawk): Tel Aviv University researchers led the recent discovery of two new planets in remote solar systems within the Milky Way galaxy. They identified the giant planets, named Gaia-1b and Gaia-2b, as part of a study in collaboration with teams from the European Space Agency (ESA) and the body’s Gaia spacecraft.The development marks the first time that the Gaia spacecraft successfully detected new planets. Gaia is a star-surveying satellite on a mission to chart a 3D map of the Milky Way with unprecedented accuracy comparable to standing on Earth and identifying a 10-shekel coin (roughly the size of a U.S. nickel) on the Moon.&nbsp;TAU’s Prof. Shay Zucker, Head of the Porter School of the Environment and Earth Sciences, and doctoral student Aviad Panhi from the Raymond and Beverly Sackler School of Physics &amp; Astronomy led the initiative. The findings were published in the scientific journal Astronomy &amp; Astrophysics.More Discoveries on the Horizon“The discovery of the two new planets was made in the wake of precise searches, using methods of artificial intelligence," said Prof. Zucker. "We have also published 40 more candidates we detected by Gaia. The astronomical community will now have to try to corroborate their planetary nature, like we did for the first two candidates."The two new planets are referred to as "Hot Jupiters" due to their size and proximity to their host star: "The measurements we made with the telescope in the U.S. confirmed that these were in fact two giant planets, similar in size to the planet Jupiter in our solar system, and located so close to their suns that they complete an orbit in less than four days, meaning that each Earth year is comparable to 90 years of that planet,” he adds.&nbsp;Giant Leaps for AstronomyThere are eight planets in our solar system. Less known are the hundreds of thousands of other planets in the Milky Way, which contains an untold number of solar systems. Planets in remote solar systems were first discovered in 1995 and have been an ongoing subject of astronomers' research ever since, in hopes of using them to learn more about our own solar system.&nbsp;To fulfil its mission, Gaia scans the skies while rotating around an axis, tracking the locations of about 2 billion suns, stars at the centre of a solar system, in our galaxy with precision of up to a millionth of a degree. While tracking the location of the stars, Gaia also measures their brightness -- an incomparably important feature in observational astronomy, since it relays significant information about the physical characteristics of celestial bodies around them. Changes documented in the brightness of the two remote stars were what led to the discovery. Aviad Panhi explains: "The planets were discovered thanks to the fact that they partially hide their suns every time they complete an orbit, and thus cause a cyclical drop in the intensity of the light reaching us from that distant sun."To confirm that the celestial bodies were in fact planets, the researchers performed tracking measurements with the Large Binocular Telescope, in Arizona, one of the largest telescopes in the world today. The telescope makes it possible to track small fluctuations in a star's movement which are caused by the presence of an orbiting planet.The discovery marks another milestone in the scientific contribution of the Gaia spacecraft’s mission, which has already been credited with a true revolution in the world of astronomy. Gaia's ability to discover planets via the partial occultation method, which generally requires continuous monitoring over a long period of time, has been doubted up to now. The research team charged with this mission developed an algorithm specially adapted to Gaia's characteristics and searched for years for these signals in the cumulative databases from the spaceship.&nbsp;Signs of Life?What about the possibility of life on the surface of those remote new planets? "The new planets are very close to their suns, and therefore the temperature there is extremely high, about 1,000 degrees Celsius, so there is zero chance of life developing there," explains Panhi. Still, he says, “I'm convinced that there are countless others that do have life on them, and it's reasonable to assume that in the next few years we will discover signs of organic molecules in the atmospheres of remote planets. Most likely we will not get to visit those distant worlds any time soon, but we're just starting the journey, and it's very exciting to be part of the search."

Israel’s Tel Aviv University team leads discovery of giant planets, similar in size to Jupiter, in remote corner of the galaxy

Two New Planets Found In Milky Way 

Washington: Computer simulations by Rice University scientists and their collaborators are the first to integrate a model of planet formation and evolution that explains two puzzling observations of exoplanets orbiting distant stars: the rarity of worlds about 1.8 times larger than Earth and the near-identical size of adjacent planets in hundreds of planetary systems.
One puzzle known as the "radius valley" refers to the rarity of exoplanets with a radius about 1.8 times that of Earth. NASA's Kepler spacecraft observed planets of this size about 2-3 times less frequently than it observed super-Earths with radii about 1.4 times that of Earth and mini-Neptunes with radii about 2.5 times Earth's. The second mystery, known as "peas in a pod," refers to neighboring planets of similar size that have been found in hundreds of planetary systems. Those include TRAPPIST-1 and Kepler-223, which also feature planetary orbits of near-musical harmony.
"I believe we are the first to explain the radius valley using a model of planet formation and dynamical evolution that self-consistently accounts for multiple constraints of observations," said Rice University's Andre Izidoro, corresponding author of a study published this week in Astrophysical Journal Letters. "We're also able to show that a planet-formation model incorporating giant impacts is consistent with the peas-in-a-pod feature of exoplanets."
Izidoro, a Welch Postdoctoral Fellow at Rice's NASA-fundedCLEVER Planets project, and co-authors used a supercomputer to simulate the first 50 million years of the development of planetary systems using a planetary migration model. In the model, protoplanetary disks of gas and dust that give rise to young planets also interact with them, pulling them closer to their parent stars and locking them in resonant orbital chains. The chains are broken within a few million years, when the disappearance of the protoplanetary disk causes orbital instabilities that lead two or more planets to slam into one another.
Planetary migration models have been used to study planetary systems that have retained their resonant orbital chains. For example, Izidoro and CLEVER Planets colleagues used a migration model in 2021 to calculate the maximum amount of disruption TRAPPIST-1's seven-planet system could have withstood during bombardment and still retained its harmonious orbital structure.
In the new study, Izidoro partnered with CLEVER Planets' investigators Rajdeep Dasgupta and Andrea Isella, both of Rice, Hilke Schlichting of the University of California, Los Angeles, and Christian Zimmermann and Bertram Bitsch of the Max Planck Institute for Astronomy in Heidelberg, Germany.
"The migration of young planets towards their host stars creates overcrowding and frequently results in cataclysmic collisions that strip planets of their hydrogen-rich atmospheres," Izidoro said. "That means giant impacts, like the one that formed our moon, are probably a generic outcome of planet formation." The research suggests planets come in two "flavors," super-Earths that are dry, rocky and 50% larger than Earth, and mini-Neptunes that are rich in water ice and about 2.5 times larger than Earth. Izidoro said new observations seem to support the results, which conflict with the traditional view that both super-Earths and mini-Neptunes are exclusively dry and rocky worlds.
Based on their findings, the researchers made predictions that can be tested by NASA's James Webb Space Telescope. They suggest, for instance, that a fraction of planets about twice Earth's size will both retain their primordial hydrogen-rich atmosphere and be rich in water. —ANI

Computer simulations by Rice University scientists and their collaborators are the first to integrate a model of planet formation and evolution that explains two puzzling observations of exoplanets orbiting distant stars: the rarity of worlds about 1.8 times larger than Earth and the near-identical size of adjacent planets in hundreds of planetary systems.

Early Planetary Migration Can Explain Missing Planets: Study

California: In a recent study, astronomers from the University of California, Irvine explain how the possibility of extraterrestrial life exists on far-off exoplanets within a special region known as the "terminator zone," which is a ring on planets that have one side that is always facing its star and one side that is always dark. "These planets have a permanent day side and a permanent night side," said Ana Lobo, a postdoctoral researcher in the UCI Department of Physics &amp; Astronomy who led the new work, which has just been published in The Astrophysical Journal. Lobo added that such planets are particularly common because they exist around stars that make up about 70 per cent of the stars seen in the night sky -- so-called M-dwarf stars, which are relatively dimmer than our sun. The terminator is the dividing line between the day and night sides of the planet. Terminator zones could exist in that "just right" temperature zone between too hot and too cold. "You want a planet that's in the sweet spot of just the right temperature for having liquid water," said Lobo, because liquid water, as far as scientists know, is an essential ingredient for life. On the dark sides of terminator planets, the perpetual night would yield plummeting temperatures that could cause any water to be frozen in ice. The side of the planet always facing its star could be too hot for water to remain in the open for a long. "This is a planet where the dayside can be scorching hot, well beyond habitability, and the night side is going to be freezing, potentially covered in ice. You could have large glaciers on the night side," Lobo said. Lobo, alongside Aomawa Shields, UCI associate professor of physics &amp; astronomy, modelled the climate of terminator planets using software typically used to model our own planet's climate, but with a few adjustments, including slowing down planetary rotation. It's believed to be the first time astronomers have been able to show that such planets can sustain habitable climates confined to this terminator region. Historically, researchers have mostly studied ocean-covered exoplanets in their search for candidates for habitability. But now that Lobo and her team have shown that terminator planets are also viable refuges for life, it increases the options life-hunting astronomers have to choose from. "We are trying to draw attention to more water-limited planets, which despite not having widespread oceans, could have lakes or other smaller bodies of liquid water, and these climates could actually be very promising," Lobo said. One key to the finding, Lobo added, was pinpointing exactly what kind of terminator zone a planet can retain liquid water. If the planet is mostly covered in water, then the water facing the star, the team found, would likely evaporate and cover the entire planet in a thick layer of vapour. But if there's land, this effect shouldn't occur. "Ana has shown if there's a lot of land on the planet, the scenario we call 'terminator habitability' can exist a lot more easily," said Shields. "These new and exotic habitability states our team is uncovering are no longer the stuff of science fiction -- Ana has done the work to show that such states can be climatically stable." Recognizing terminator zones as potential harbours for life also means that astronomers will need to adjust the way they study exoplanet climates for signs of life because the biosignatures life creates may only be present in specific parts of the planet's atmosphere. The work will also help inform future efforts by teams using telescopes like the James Webb Space Telescope or the Large Ultraviolet Optical Infrared Surveyor telescope currently in development at NASA as they search for planets that may host extraterrestrial life. "By exploring these exotic climate states, we increase our chances of finding and properly identifying a habitable planet in the near future," said Lobo. —ANI

In a recent study, astronomers from the University of California, Irvine explain how the possibility of extraterrestrial life exists on far-off exoplanets within a special region known as the "terminator zone," which is a ring on planets that have one side that is always facing its star and one side that is always dark.

Terminator Zones On Distant Planets Could Harbour Life: Research

Toronto: An international team of astronomers has discovered 62 new moons orbiting Saturn, taking the total number to 145.
The planet is back into first place in the Solar System's 'moon race' after being briefly overtaken by gas giant Jupiter. The new discoveries mean that Saturn has not only regained its crown for having the most known moons (overtaking Jupiter with 95 recognised moons), but it's also the first planet to have over 100 discovered moons, said researchers at the University of British Columbia(UBC).
Jupiter, which added 12 moons to its tally in February, has 95 moons that have been formally designated by the International Astronomical Union (IAU).
"Saturn not only has nearly doubled its number of moons, it now has more moons than all the rest of the planets in the solar system combined," said Prof Brett Gladman, an astronomer at the UBC, the Guardian reported.
The new moons, which have been assigned strings of numbers and letters for now, will eventually be given names based on Gallic, Norse and Canadian Inuit gods, in keeping with convention for Saturn's moons.
All of the new moons are in the class of irregular moons, thought to be initially captured by their host planet long ago. Irregular moons are characterised by their large, elliptical, and inclined orbits compared to regular moons.
The number of known saturnian irregular moons has more than doubled to 121, with 58 previously known before the search began. Including the 24 regular moons, there is now a total of 145 recognised by the IAU.
The irregular moons tend to clump together into orbital groups based on the tilt of their orbits.
The team, led by Dr. Edward Ashton, who started the research project at UBC, and currently a postdoctoral fellow at Taiwan's Academia Sinica Institute of Astronomy and Astrophysics, used data taken using the Canada-France-Hawaii Telescope (CFHT) on top of Mauna Kea, Hawaii between 2019 and 2021.
By shifting and stacking many sequential images taken during three hour spans, they were able to detect moons orbiting Saturn down to about 2.5 kilometres in diameter.
The original discovery search was done in 2019, uncovering the moons in a meticulous search of the deep CFHT imaging acquired that year.
To be absolutely sure, objects must be tracked for several years before they can be designated as certainly orbiting the planet. After painstakingly matching objects detected on different nights over two years, the team managed to track 62 objects, confirming them as new moons. —IANS

An international team of astronomers has discovered 62 new moons orbiting Saturn, taking the total number to 145.

Saturn Beats Other Planets With Most Number Of Moons In Solar System

Florida: Researchers found, in the Milky Way, the yellow sun is comparatively uncommon. The vast majority of stars are far smaller, colder, and only have up to half the sun's mass. In our galaxy, countless planets orbit these familiar dwarf stars. These planets would have to be extremely close to their little stars in order to accumulate enough heat to be habitable, making them vulnerable to strong tidal forces. The study was published in the journal, 'Proceedings of the National Academy of Sciences. The University of Florida astronomers have found that two-thirds of the planets near these commonplace tiny stars might be sterilised by these tidal extremes by roasting them in a new analysis based on the most recent telescope data. But that still leaves one-third of the planets--hundreds of millions around the galaxy--that might be in an orbit just right for holding onto liquid water and perhaps supporting life. The week of May 29, research by UF astronomy professor Sarah Ballard and doctoral candidate Sheila Sagear was published in the Proceedings of the National Academy of Sciences. Exoplanets, or planets that orbit stars other than the sun, have long been the subject of research by Ballard and Sagear. "I think this result is really important for the next decade of exoplanet research because eyes are shifting toward this population of stars," Sagear said. "These stars are excellent targets to look for small planets in an orbit where it's conceivable that water might be liquid and therefore the planet might be habitable." Sagear and Ballard measured the eccentricity of a sample of more than 150 planets around these M dwarf stars, which are about the size of Jupiter. The more oval-shaped an orbit, the more eccentric it is. If a planet orbits close enough to its star, at about the distance that Mercury orbits the sun, an eccentric orbit can subject it to a process known as tidal heating. As the planet is stretched and deformed by changing gravitational forces on its irregular orbit, friction heats it up. At the extreme end, this could bake the planet, removing all chance for liquid water. "It's only for these small stars that the zone of habitability is close enough for these tidal forces to be relevant," Ballard said. Data came from NASA's Kepler telescope, which captures information about exoplanets as they move in front of their host stars. To measure the planets' orbits, Ballard and Sagear focused especially on how long the planets took to move across the face of the stars. Their study also relied on new data from the Gaia telescope, which measured the distance to billions of stars in the galaxy. "The distance is really the key piece of information we were missing before that allows us to do this analysis now," Sagear said. Sagear and Ballard found that stars with multiple planets were the most likely to have the kind of circular orbits that allow them to retain liquid water. Stars with only one planet were the most likely to see tidal extremes that would sterilize the surface. —ANI

Researchers found, in the Milky Way, the yellow sun is comparatively uncommon. The vast majority of stars are far smaller

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China Proposes Search For Nearby Habitable Planets Via Space Telescope

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China Proposes Search For Nearby Habitable Planets Via Space Telescope

Inam Ansari

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