Newly discovered Earth-sized exoplanet may be best candidate yet for alien life

Artist’s conception of Ross 128 b. Image Credit: ESO/M. Kornmesser

Astronomers just announced the discovery of yet another exoplanet, just one of thousands now, but this one is quite interesting and exciting for a variety of reasons. The planet, called Ross 128 b, is an Earth-sized world orbiting a star only 11 light-years away. Not only is it nearly the same size as Earth, the observations show that it is likely quite temperate, with temperatures similar to those on our planet as well. These findings make it possibly the best exoplanet candidate yet in the search for extraterrestrial life.

Ross 128 b was discovered by astronomers using the High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile, which is operated by the European Southern Observatory (ESO).

“This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques. Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations,” said Nicola Astudillo-Defru from the Geneva Observatory – University of Geneva, Switzerland), who co-authored the discovery paper.

The planet orbits the red dwarf star Ross 128 every 9.9 days. Even though it orbits so close to the star, temperatures are calculated to be temperate, since the star is a lot smaller and cooler than our Sun. There is still some debate as to whether the planet is actually inside the “habitable zone” of the star, where liquid water could most likely exist on the surface, but what astronomers have learned so far makes them optimistic that the planet could be quite potentially habitable. Since Ross 128 b receives only 1.38 times more irradiation than the Earth, its equilibrium temperature is estimated to lie between -60°C and 20°C (-76°F and 68°F). Not bad.

Ross 128 b is now the second closest known Earth-sized temperate exoplanet. The one orbiting Proxima Centauri is closer, but that red dwarf star is more active than Ross 128, sending out frequent, intense flares which could adversely affect the habitability of any planets there. Ross 128 is much quieter.

Many exoplanets are now being discovered orbiting red dwarf stars, which are the most common stars in our galaxy. There are now estimated to be billions of planets in our galaxy alone.

Another interesting fact is that while Proxima Centauri is currently the closest star to us, apart from the Sun of course, Ross 128 is gradually moving closer and in about 79,000 years will become the closest star.

The discovery of Ross 128 b is raising some eyebrows for another reason as well – its star is the same one that was in the news this past spring and summer when SETI astronomers detected unusual radio signals coming from the direction of the star, first heard in May 2017. At the time, it was tentatively concluded that they were probably from an unknown satellite and not aliens, but this new discovery may prompt astronomers to take another look.

“So sadly, we’ve already looked closely at Ross 128 and have come up empty. Nonetheless, as Ross 128b is such an exciting target, we are considering additional, deeper observations at radio and optical wavelengths. Nearby exoplanets are particularly exciting from a SETI perspective as they permit us to search for and potentially detect much weaker signals than from more distant targets.”

Ross 128 b will also be a prime target for ESO’s upcoming Extremely Large Telescope (ELT), which would be capable of detecting possible biomarkers in its atmosphere such as oxygen. Other closer exoplanets will also be able to be studied in this way in the next few years, by ELT and other telescopes, perhaps bringing us closer than ever before to finding the holy grail of exoplanetology – another inhabited world.

The new research paper is available here.

This article was first published on Futurism.

 

From Jupiter to the Universe: First science targets chosen for James Webb Space Telescope

Artist’s conception of the James Webb Space Telescope in space. Image Credit: Northrop Grumman

The James Webb Space Telescope (JWST) may not be launching until 2019, but the first targets for the powerful new observatory have already been chosen, including Jupiter, organic molecules in star-forming clouds and baby galaxies in the distant Universe. JWST is the long-awaited “successor” to the Hubble Space Telescope and will provide unprecedented new views of the Universe.

These first targets were chosen from 100 different proposals as part of a competitive peer-review selection process and have been allotted nearly 500 hours of observing time.

“We were impressed by the high quality of the proposals received. These programmes will not only generate great science, but will also be a unique resource for demonstrating the investigative capabilities of this extraordinary observatory to the worldwide scientific community,” said Ken Sembach, director of the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “We want the research community to be as scientifically productive as possible, as early as possible, which is why I am so pleased to be able to dedicate nearly 500 hours of director’s discretionary time to these early release science observations.”

Jupiter, as seen here recently by the Juno spacecraft, will be one of the first targets of JWST. Image Credit: NASA/SwRI/MSSS/Gerald Eichstädt/Seán Doran

One great aspect of these observations is that the data will be publicly available immediately, which will help astronomers plan follow-up observations, as well as, of course, benefitting the public in general.

Four of the first set of observations will be led by astronomers from ESA, while JWST itself is a collaboration of ESA, NASA and the Canadian Space Agency.

“It is exciting to see the engagement of the astronomical community in designing and proposing what will be the first scientific programmes for the James Webb Space Telescope,” noted Alvaro Gimenez, ESA Director of Science.

The Hubble Space Telescope already revolutionized our knowledge about the Universe, and now JWST will expand on that.

Engineers conducting a white light inspection of the James Webb Space Telescope’s large mirror. Photo Credit: NASA/Chris Gunn
Diagram depicting different parts of JWST. Image Credit: NASA

“Webb will revolutionise our understanding of the Universe and the results that will come out from these early observations will mark the beginning of a thrilling new adventure in astronomy,” said Gimenez.

JWST will search for the earliest galaxies in the Universe, and study the massive black holes at their centers, as well as observe the birth of new stars and planetary systems. As reported earlier, JWST will also look at Europa and Enceladus, two ocean moons in our Solar System which are thought to be able, maybe, to support some form of life.

One of the most exciting objectives of JWST is to analyze the atmospheres of some closer exoplanets, including to search for possible biomarkers as evidence of life. An increasing number of exoplanets which are near Earth-sized and/or in the habitable zones of their stars are being discovered by astronomers, and JWST will help to narrow down which ones are potentially the most habitable.

One of the most exciting tasks of JWST will be to examine some nearby exoplanets for possible signs of life in their atmospheres. Image Credit: NASA Ames/SETI Institute/JPL-Caltech

“I’m thrilled to see the list of astronomers’ most fascinating targets for the Webb telescope, and extremely eager to see the results. We fully expect to be surprised by what we find,” said John C. Mather, Senior Project Scientist for the Webb telescope and Senior Astrophysicist at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

JWST had been scheduled to launch in October 2018, but that date was pushed backed to spring 2019.

This article was first published on AmericaSpace.

 

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Getting closer to Earth 2.0: Astronomers discover 20 new potentially habitable exoplanets

Diagram depicting regions of stars which have been observed by Kepler during the K2 phase of its mission. Image Credit: NASA Ames/W. Stenzel

Exoplanets, planets orbiting stars other than the Sun, are being discovered by the thousands now, and there are estimated to be billions of them in our galaxy alone. So far, they have ranged from worlds smaller than Earth, to “super-Earths” and “hot Jupiters” – a wide variety of sizes, compositions and temperatures. For many people, the most interesting are the ones which could potentially support life of some kind. How many of these planets may actually be habitable, at least by earthly standards? As technology improves, astronomers are getting closer to tentatively answer some of these questions, and a few dozen or so such planets have been identified so far. Now, a large team of researchers have found 20 more exoplanets which might be capable of supporting life. The findings are based on data sent back by NASA’s Kepler Space Telescope.

The planets were found by using a tool called a Robovetter to sift through the data and narrow down the the most interesting candidates.

It should also be noted that these are still planetary candidates, and further observations will be needed to fully confirm them. The great majority of exoplanet candidates do end up being confirmed, with relatively few being false positives.

Out of the candidates, two are in multi-planet systems and ten are near-Earth size, in the habitable zones of their stars.

One of the planets in particular stood out, KOI-7923.01, which was found to have an orbit of 395 days and was close to Earth in size. The planet is a little cooler than Earth due to its distance from its star, relative to Earth’s orbit, and the star being cooler than the Sun. Initial studies suggest that the planet is likely covered by a frozen tundra, but may not be too cold for life.

Many of the other planets have long orbits as well. To date, most of the exoplanets discovered so far have had shorter orbits closer to their stars, since they are the easiest to detect.

These new likely exoplanets were found in photometry data sent back by Kepler over four years, before the problems with the telescope’s reactor wheels which ended the primary mission in 2013. They were part of a catalogue of 8,054 “Kepler Objects of Interest” that were pared down to 4,034 exoplanets believed to have orbits between .25 and 632 days. Kepler, although hobbled, is currently in its K2 mission phase, observing different regions of stars than before.

Most of the exoplanets discovered so far have been ones about the size of Neptune or smaller. Many of those are rocky “super-Earths” which are smaller than Neptune, but larger than Earth. Others have been about the size of Earth or smaller, while others are gas giants like Jupiter. To date, 3,497 have been confirmed altogether according to the Open Exoplanet Catalogue with another 4,496 candidates and 2,337 confirmed from Kepler alone.

Kepler also discovered the enigmatic dips in brightness of the now-famous star called Boyajian’s Star, which astronomers have been trying to explain for a few years now. It’s weird behaviour of suddenly dimming by up to 22%, as well as more subtle long-term variations in brightness, have produced theories ranging from giant planets with giant ring systems to disintegrating planets or massive comets to alien mega-structures.

The Habitable Exoplanets Catalog currently lists 52 other potentially habitable exoplanets, apart from these new ones. 30 are super-Earth or mini-Neptune size, 21 are Earth-size and 1 is Mars-size. That number will surely continue to grow in the months and years ahead.

The new exoplanet paper is available here.

This article was first published on Futurism.

 

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NASA designs advanced new SELFI instrument to help search for life on Enceladus

The plumes of Enceladus: SELFI would study their composition in more detail than ever before. Photo Credit: NASA/JPL/Space Science Institute

Is there life on Enceladus? Are there any Enceladan bacteria or other little critters swimming in that alien ocean on this tiny moon of Saturn? We don’t know yet, but there is compelling evidence from the Cassini mission for at least a habitable environment in the dark waters below the icy crust. What’s needed now is to return to Enceladus with new and better instruments, designed especially to search for signs of active biology, which Cassini couldn’t do. Now, a new instrument has been designed by NASA which would further study the water vapour plumes erupting from the moon’s south pole and analyze what’s in them in more detail than previously possible. Those plumes are tantalizingly connected to the salty subsurface ocean below the surface ice.

The new instrument is called the Submillimeter Enceladus Life Fundamentals Instrument (SELFI) which would measure trace chemicals in the plumes. SELFI would be able to simultaneously detect and analyze 13 molecular species, including water in various isotopic forms, as well as methanol, ammonia, ozone, hydrogen peroxide, sulfur dioxide, and sodium chloride (the same salt in Earth’s oceans). These measurements would provide specific clues as to the composition and habitability of the subsurface ocean.

Diagram of an interior cross-section of the crust of Enceladus, showing how hydrothermal activity is thought to be causing the plumes of water vapour on the surface. Image Credit: NASA-GSFC/SVS/NASA/JPL-Caltech/Southwest Research Institute
Map of the Tiger Stripe fractures at the south pole of Enceladus, with plume locations marked by white circles. Cassini’s flight path during one close flyby is marked by the red line. Image Credit: NASA/JPL-Caltech/Space Science Institute

“Submillimeter wavelengths, which are in the range of very high-frequency radio, give us a way to measure the quantity of many different kinds of molecules in a cold gas. We can scan through all the plumes to see what’s coming out from Enceladus,” said SELFI Principal Investigator Gordon Chin. “Water vapour and other molecules can reveal some of the ocean’s chemistry and guide a spacecraft onto the best path to fly through the plumes to make other measurements directly.”

“Molecules such as water and carbon monoxide, and others, are like little radio stations that broadcast on very specific frequencies that say, ‘hey, I’m water, I’m carbon monoxide,’” Chin added.

“SELFI is really new,” Chin said. “This is one of the most ambitious submillimeter instruments ever built.”

Close-up view of plume activity in one of the Tiger Stripe fractures at the south pole of Enceladus. Photo Credit: NASA/JPL/Space Science Institute
Another close-up view of rough surface terrain on Enceladus. Photo Credit: NASA/JPL/Space Science Institute
A more global view of Enceladus. Photo Credit: NASA/JPL/Space Science Institute

SELFI would be much more sensitive than previous similar submillimeter instruments. With it, scientists could measure very small amounts of trace gases, even at the extremely cold temperatures of the moon’s surface, and explore the system of the surface vents themselves.

“The spectral lines are so discrete that we can identify and quantify chemicals with no confusion whatsoever,” said Paul Racette, a Goddard engineer who is the project’s chief systems engineer.

The water vapour plumes were previously analyzed by Cassini, and found to also contain ice particles, organics, carbon dioxide, methane and salts. The plumes erupt through huge cracks called Tiger Stripes in the icy surface crust, originating from a global subsurface ocean. There is also now evidence from Cassini for active hydrothermal vents on the bottom of that ocean, much like in oceans on Earth.

SELFI would be a great tool in the search for life on Enceladus (and perhaps Europa also?). Now all that’s needed is a mission to send it on.

This article was first published on AmericaSpace.

 

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Juno mission gets new project manager as spacecraft completes eighth science flyby of Jupiter

Illustration of Juno near Jupiter, which combines real images of the planet from the spacecraft with Juno artistically “added in.” Image Credit: NASA/JPL-Caltech

NASA’s Juno spacecraft has successfully completed its eighth science flyby of Jupiter, passing over the gas giant’s swirling cloud tops once again as it continues to unravel the mysteries of the largest planet in the Solar System. The mission itself also now has a new project manager, who will oversee the continuing flow of information being sent back, which has already greatly expanded our knowledge of Jupiter, upending some theories and presenting new questions.

“All the science collected during the flyby was carried in Juno’s memory until yesterday, when Jupiter came out of solar conjunction,” said the new Juno project manager, Ed Hirst, from NASA’s Jet Propulsion Laboratory in Pasadena, California. “All science instruments and the spacecraft’s JunoCam were operating, and the new data are now being transmitted to Earth and being delivered into the hands of our science team.”

The flyby actually occurred on Oct. 24, (Perijove 9) but the confirmation of its success was delayed until Oct. 31 by the solar conjunction, which interrupts communications between the spacecraft and Earth.

New enhanced view of Jupiter’s turbulent atmosphere, from the most recent flyby on Oct. 24, 2017. Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson
New enhanced view of Jupiter’s turbulent atmosphere, from the most recent flyby on Oct. 24, 2017. Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson
New enhanced view of Jupiter’s turbulent atmosphere, from the most recent flyby on Oct. 24, 2017. Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Björn Jónsson

Juno has been busy orbiting Jupiter since July 4, 2016, using its instruments to study the planet’s atmosphere, clouds and auroras. At its closest, the spacecraft passes within 3,400 kilometres (2,100 miles) of Jupiter’s cloud tops, providing unprecedented views of the turbulent atmosphere, which often looks like it was painted by a cosmic watercolour artist.

“There is no more exciting place to be than in orbit around Jupiter and no team I’d rather be with than the Juno team,” said Hirst. “Our spacecraft is in great shape, and the team is looking forward to many more flybys of the Solar System’s largest planet.”

Juno previously found that Jupiter’s auroras seem to “defy earthly laws of physics” and are much more powerful than any on Earth. The auroras have also been studied more recently by NASA’s Chandra X-ray Observatory. The data from Juno has also shown that Jupiter is more complex internally than previously thought, with current theories being turned on their heads.

New Chandra image comparison of auroras seen at Jupiter’s north and south poles. Image Credit: X-ray – NASA/CXC/UCL/W.Dunn et al; Optical, South Pole – NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Doran; North Pole – NASA/JPL-Caltech/SwRI/MSSS
Jupiter as seen by Juno on Oct. 24, 2017. Image Credit: NASA/JPL-Caltech/MSSS/SwRI/Kevin M. Gill
Jupiter as seen by Juno on Oct. 24, 2017. Image Credit: NASA/JPL-Caltech/MSSS/SwRI/Kevin M. Gill
Earlier image showing closest-ever view of Jupiter’s Great Red Spot from Juno. Image Credit: NASA/JPL-Caltech/MSSS/SwRI/Kevin M. Gill

“Almost nothing is as we anticipated,” Juno’s principal investigator Scott Bolton earlier told WIRED. “But it’s exciting that Jupiter is so different than we assumed.”

Juno was first launched on Oct. 5, 2011, and is the first spacecraft to visit Jupiter since Galileo, which ended its mission on Sept. 21, 2003 by intentionally plummeting into Jupiter’s atmosphere, much like the Cassini probe did at Saturn last September.

Ed Hirst is the new project manager for Juno, who has worked on the mission since the beginning, and also worked on the Galileo, Stardust and Genesis missions. He replaces Rick Nybakken, who was recently appointed deputy director for JPL’s Office of Safety and Mission Success.

Juno’s next close flyby of Jupiter will be on Dec. 16, 2017.

This article was first published on AmericaSpace.

 

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