As we enter 2018, NASA’s Curiosity rover continues to be busy exploring on top of Vera Rubin Ridge, on the lower flanks of Mount Sharp. The rover is gradually making its way farther up the flanks, closing in the picturesque foothills in front of it. As it does so, Curiosity has made two new interesting discoveries, which may have implications for the possibility of life.
When searching for extraterrestrial life, the focus tends to be, naturally, on worlds far away, such as Mars, Europa or distant exoplanets. But could there be evidence closer to home, even near Earth itself? It’s a seemingly unlikely but not unheard of possibility. That said, there is an interesting new report from the Russian news agency TASS that living “alien” bacteria have been found on the outside of the International Space Station (ISS). Say what?
While such a discovery would be incredible, a healthy amount of skepticism is called for.
The bacteria were discovered by Russian cosmonaut Anton Shkaplerov, in samples swabbed from outside surfaces of the ISS in 2014 and the subject of study since then. This included locations with an accumulation of fuel wastes which were discharged during the operation of the engines and more obscure sections of the station’s surface.
As noted in the report, the bacteria found “were absent during the launch of the ISS module.” In other words, they came from somewhere else.
“That is, they have come from outer space and settled along the external surface,” Shkaplerov said. “They are being studied so far and it seems that they pose no danger.”
Other bacteria, known to be from Earth, were also found in computer tablets brought up to the station.
Little, if anything, is (publicly) known yet about the actual characteristics of the “alien” bacteria. The fact that they were found on the outside of the ISS, in low-Earth orbit, is intriguing, but nothing conclusive can be said until it can be determined they didn’t originate from Earth itself. There are many different kinds of microorganisms on Earth, and it is possible that some could get lofted into low-Earth orbit. They are already known to exist in the upper atmosphere and it’s also known that at least one type of microorganism can survive in space itself for some periods of time – tardigrades (water bears). In 2007, some living tardigrades were sent into space on the outside of a FOTON-M3 rocket for ten days by European researchers. 68 percent of them survived the trip, including coming back to Earth. Perhaps there are some other tiny Earthly bugs which could do that as well.
More research needs to be done with the samples taken, and new samples would be even better – Shkaplerov is going back into orbit next month.
The microbes might be a species previously unknown which inhabit the upper atmosphere, or somehow got ejected into space from further down, whether from rocket launches or some other means. At this point it is most likely that they originate from Earth, but it will be interesting to see what comes of follow-up research being conducted.
It’s also possible that these are earthly bacteria which have been affected by the harsh conditions in space including temperature fluctuations, no gravity and cosmic radiation. Such conditions might change them enough to be almost unrecognizable. One time, even a flatworm taken up to the space station grew an extra head.
Previously, it was also claimed that Russian cosmonauts had found traces of sea plankton on the windows of the ISS.
“[Plankton in] such phases of development is found on the surface of the ocean. It isn’t characteristic to Baikonur (Cosmodrome, from where supplies are launched to the space station),” said Vladimir Solovyev, chief of the Russian ISS orbital mission. “It turns out that there are some rising air currents, which settle on the surface of the station.”
As of yet, NASA has not commented on this purported discovery. These may yet turn out to be alien space critters, but the answer is probably more down to Earth.
This article was first published on Futurism.
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.
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.
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.
“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.”
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.