Professor Sara Seager of Massachusetts Institute of Technology says her team of scientists is looking for biosignatures from gases emitted by alien life forms on habitable extrasolar planets. Many of these gases could be detected remotely by telescopes, but could end up having quite different compositions from those in the atmosphere of our planet.
Prof. Seager and her colleagues explained,
“Thousands of exoplanets are known to orbit nearby stars. Plans for the next generation of space-based and ground-based telescopes are fueling the anticipation that a precious few habitable planets can be identified in the coming decade. Even more highly anticipated is the chance to find signs of life on these habitable planets by way of biosignature gases.”
Seager’s team proposes in their paper published online in the journal Astrobiology that all stable and potential volatile molecules should be considered as possible biosignature gases, laying the groundwork for identifying such gases by conducting a massive search for molecules with six or fewer non-hydrogen atoms in order to maximize their chances of recognizing biosignature gases. They say they promote the concept that “all stable and potentially volatile molecules should initially be considered as viable biosignature gases.”
The scientists created a list of about 14,000 molecules that contain up to 6 non-H atoms. About 2,500 of these are CNOPSH (C – carbon, N – nitrogen, O – oxygen, P – phosphorus, S – sulfur, and H – hydrogen) compounds.
This means that instead of the costly and controversial method of netting strange creatures from the bottom of the sea, these scientists have decided to search and find thousands of curious, potentially biogenic gas molecules.
On May 30, our cold, red sandy neighbor outside Earth’s orbit is getting very close to us, at least for a short duration of time.
Scientists say Mars will be closer to Earth than it’s been since the past eleven years. At about 46.8 million miles away, it’s still a rather distant journey away, but the planet can typically be about 250 million miles away.
According to NASA, from May 18th until June 3rd, the great red planet will be bigger, brighter and hopefully more visible, weather permitting.
Skywatchers should expect to see a reddish star in the mornings at dawn or slightly before, if you are in the UK. United States watchers should look for it around midnight.
For a better view, look up your local astronomy club where members are likely to have powerful telescopes. If you’re looking for a telescope yourself, check out the Celestron C9.25 and get ready for some mindblowing astronomy at home.
Recently, NASA revealed about some sensitive details concerning massive storms that destroyed Mars’ atmosphere. They went on to enquire how ready are we to accept and combat such a “high impact event.” This announcement comes after NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, which spotted how the massive storm that, stripped away the planet’s atmosphere.
Commenting on this activity, Joe Grebowsky, MAVEN’s project scientist said that solar storms and wind corrosion is the key reason for atmospheric loss, and was the main cause for the major changes in the Martian climate.
Post September 2014, MAVEN has pointed out this storm to be the largest. The most important reason why it has become a cause of concern is that such abnormal weather activity can hamper technology-based infrastructures and give rise to many unforeseen accidents.
In 2012, a coronal mass ejection (CME) solar storm just missed a possible collision with earth, due to a sudden eruption in sun. Associating, the current situation, scientists say if such thing is repeated today, the human kind is all set to witness a massive a technological disaster like destroyed satellites, non-functional GPS system.
As far as the costs are concerned Llyod’s pointed out that to prevent from such solar storm will cost somewhere between $600 billion and $2.6 trillion.
Astronomers from the University of Birmingham’s School of Physics and Astronomy in the United Kingdom have recently identified “hot super-Earths” with stripped surfaces. They identified this with the help of data coming from NASA’s exo-planet hunter spacecraft named Kepler.
The exo-planets are made up of rocky core and gaseous outer surface. The host stars of these exo-planets appear to be very close due to which the surfaces of these exo-planets get violently stripped. This is because of being violently hit by a torrent of high energy radiation. This surprising revelation comes from the study published in journal- Nature Communications.
The continuous persistent erosion of atmosphere by high radiations comparatively affects the original size of the planets. As per the results disclosed by the astronomers, the planets with hot stars close to their surfaces had different appearances in terms of size and looks, originally.
Researches and astronomers use asteroseismology in order to study the internal properties of these planets and their host stars. The results of studies play an important role in implying the evolution of stellar systems- our solar system, its planets and their host stars.
New generation satellites including the NASA Transiting Exoplanet Survey Satellite (TESS) Goal are in a process of being launched to extract and gather additional information about these stripped exo-planets.
Scientists at the Smithsonian have discovered a giant planet with three suns and which is 685 light years from us.
They said that while one of its Sun is about 40 times more intense than our Sun. It was also believed by the scientists that the KELT-4 system, which is home to a “Hot Jupiter” planet known as KELT-4Ab, is a binary system. However, it was recently discovered that it is instead a binary pair. This finding was possible by the use of two telescopes located in Arizona and South Africa. These two telescopes when combined together are known as Kilodegree Extremely Little Telescope (KELT).
The other two stars, KELT-4B and KELT-4C appeared dimmer, and could be compared to the Earth’s moon.
The star KELT -4A is close to us and it is brighter, making it easier to study. The other two suns are comparatively far away, dimmer and not that large. It takes KELT-4Ab just three days to orbit KELT-4A.The temperature on Hot Jupiter is very high, touching around thousands of degrees Fahrenheit.
KELT-4Ab is the fourth exoplanet, which has been discovered to have three suns. This giant planet is much closer to earth compared to other three planets therefore, it is much more convenient to observe it closely.
Jason Eastman and his colleagues at the Harvard-Smithsonian Center for Astrophysics, plan to further study these stars, and they aim to find out how their gravity pushed KELT-4Ab into such a hot spot.
Comparing the planet you live on to the size of other celestial bodies has got to be one the biggest mind-blowing experiences a human can go through. To put yourself into perspective and recognize that we are but a nano-blip on the radar of extraterrestrial life makes it all that much more apparent why we haven’t been visited yet… or have we…?
Last month NASA gave the “all systems go” for a new mission to Europa. But why go back? After all, we’re still sifting through the data from the Galileo probes fly-bys from more than a decade ago.
The short answer: it’s all about life.
The Jovian moons – named after Jupiter’s lovers by Simon Marius – have been a source of scientific speculation since Galileo trained his telescope on Jupiter in 1610, announcing his discovery in the Sidereal Messenger.
But the idea that Europa and other moons of Jupiter might harbour life is relatively new, as is the notion they might have hidden oceans beneath their icy surfaces. Indeed, these speculations demonstrate just how fast our conceptions of the solar system, and life, can change.
Speculative science, speculative fiction
A generation of space scientists and enthusiasts who grew up on Robert A. Heinlein’s “juveniles” will fondly remember Farmer in the Sky, written in 1950, when the Jovian moons were believed to be rocky, like our own Moon.
But in the late 1950s and continuing through the early 1970s, a growing body of telescopic data suggested that some of these moons, in particular Callisto, Ganymede and Europa, were covered in water ice. This speculation came from their high albedo, a measure of how much they light they reflect. With an albedo of 0.64, Europa is one of the most reflective bodies in the solar system.
In 1971, Carl Sagan suggested that the Jovian moons, including Europa, were of “major…exobiological significance”. In other words: they might harbour life.
Europa as seen by Voyager 2 during its close encounter in 1979. NASA/JPL
The early 1970s also saw the first speculation that some outer moons of the solar system, including Europa, might hide an ocean beneath their surfaces. It was initially suggested this might be due to radiative heating, although it was later proposed that the heat might come from tidal forces induced by Jupiter, especially because of the synchronous orbits of the three innermost Galilean moons: Io, Europa and Ganymede.
The 1979 Voyager fly-bys confirmed that Callisto, Europa and Ganymede moons were covered in ice and that Io was extremely volcanic. The best images of Europa were taken by Voyager 2 from a range of 204,400 kilometres, showing Europa to be “billiard ball” smooth.
Not too hot, not too cold…
Things took a turn following the discovery by Robert Ballard’s 1977 expedition of entire ecosystems thriving near hydrothermal vents in the deep ocean. These vents existed in the “midnight zone”, without sunlight and photosynthesis, and changed the way we thought about life.
The discovery of life around deep ocean vents, like this one, raised the exciting prospect of life existing under the ocean on Europa. P. Rona/NOAA
In 1980, scientists Gerald Feinberg and Robert Shapiro hypothesised that deep sea volcanism might support life on the Jovian moons. The Feinberg-Shapiro hypothesis is one of the major reasons for the current interest in Europa by astrobiologists.
In essence, it was proposed there might be a tidally heated habitable zone around giant planets, similar to the habitable, or “Goldilocks” zone around a star: where it’s not to hot, not to cold, and where liquid water and life can exist.
The idea of life on the Jovian moons was quickly picked up by science fiction writers. In Arthur C. Clarke’s 2010: Odyssey two (1982) and 2061: Odyssey three (1988), aliens transform Jupiter into a star kick-starting the evolution of life on Europa, transforming it into a tropical ocean world forbidden to humans.
In Bruce Sterling’s 1985 Nebula Award nominee, Schismatrix, Europa’s ocean is colonised by a group of genetically transformed post-human species.
Fire and ice
Europa and life were thus well and truly established in the minds of science fiction writers, planetary scientists, exobiologists and the public by the time NASA’s extraordinary Galileo mission began taking images of Europa in 1996.
This is the colour view of Europa from Galileo, taken in the 1990s, that shows the largest portion of the moon’s surface at the highest resolution. NASA/JPL
By the completion of its primary mission on December 7 1997, Galileo had made eleven encounters with Europa. Galileo’s extended mission became one of “fire and ice”: its twin foci were Io’s vulcanism and Europa’s icy oceans. The Europa fly-bys took the probe to within a few hundred kilometres of the moon’s surface.
These extensive observations of Europa by the Galileo mission were compelling evidence for a liquid water ocean some 100 to 200 kilometres thick on which “floats” an outer shell of ice. Magnetometer measurements indicate the ocean is free flowing and salty.
Galileo also provided spectacular views of the icy terrain: ridges, slip faults and “ice-bergs”, all adding to the picture of a surface only 10-100 million years old, which is young by the four to five billion year age of the solar system.
The spacecraft, nearly out of fuel after an extended mission, was deliberately crashed into Jupiter on 21 September 2003 to protect Europa from possible contamination.
Europa Report
The data Galileo collected are still revealing new important finds. There evidence of clay-like minerals on the surface, possibly from asteroid or meteorite collision, and signs of sea salt, discoloured by radiation, making up some of the dark patches observed by both Voyager and Galileo.
A whole new generation of scientists is eagerly awaiting the data from the new mission. Astrobiology has become, since the early 2000s, a whole new science discipline. This “alien ocean” mission is clumsily named, at present, Europa Multiple Flyby Mission.
So the new mission, slated for a rendezvous with Europa in 2030, won’t involve a lander. And until we can send a probe into the icy depths of Europa’s sea, speculation about what might be lurking there, à la Sebastián Cordero’s Europa Report, will remain the domain of science fiction and scientists’ fantasy. Maybe one day, it will be science fact. Europa, here we come.
Astronauts on the early Apollo missions orbiting over to the dark side of the moon were surprised to discover a mysterious, bright crescent of light glowing at the horizon. The controversial explanation was sunlight scattered by dust high in the Moon’s tenuous atmosphere, but proof has been hard to come by. Fast forward half a century and, for the first time, a team of scientists has analysed the Moon’s atmospheric dust in real time, discovering a permanent dust cloud. Surprisingly, however, they have failed to explain the glow.
Despite its proximity, there’s a lot we don’t know about the Moon – in particular about its atmosphere. The glow was first spotted in 1966 and 1968 by cameras onboard NASA’s Surveyer landers – the robotic precursors to manned Apollo landings. It has later been seen by astronauts on some Apollo missions, but not all.
The white area on the edge of the moon is the glow, and the bright dot at the top is the planet Venus. NASA
The team of scientists trying to understand the dust environment of the Moon, including the lunar glow, discovered a permanent, elongated cloud of dust around the Moon at heights between 10 to 260 km above the lunar surface using NASA’s Lunar Astmosphere and Dust Environment Explorer (LADEE) spacecraft. The authors argue that this cloud is caused by high-speed bombardment by dust particles from comets.
Interplanetary dust particles are thought to hit the surfaces of airless bodies in the solar system, generating charged and neutral gas clouds, as well as secondary dust particles that are ejected from the surface of the body on impact.
Clouds of dust particles, bound by gravitational forces, have been found around the icy moons of Jupiter and Saturn. But until now, none had been identified around rocky bodies with dusty surfaces such as the Earth, Moon and Mars.
Has lunar glow explanation turned to dust?
The gravitational pull of the Moon is approximately one-sixth of that of Earth, which is thought to be too weak to maintain a permanent and substantial atmosphere. Instead, the Moon has a tenuous layer of neutral gas called an exosphere. Debate over the presence of dust in that exosphere has raged ever since sightings of the lunar horizon glow during the Apollo era.
The team behind the study used an instrument called the Lunar Dust Experiment (LDEX) designed to study the physical characteristics and origin of lunar dust over a period of time, including during meteoroid showers. It was developed to search for a high-density dust cloud that could account for the glow seen by the Apollo astronauts. With superior sensitivity and closer approach to the Moon than previous missions, LDEX recorded 140,000 dust hits at various altitudes from the lunar surface and for a range of dust particle sizes.
The team estimated the average total mass of the dust cloud to be 120kg. However, unlike the dust atmosphere’s of Jupiter’s moons, the lunar dust cloud is not evenly distributed or spherically symmetric. Instead, the authors found that the cloud is elongated in a way that matches the properties of the incoming interplanetary dust bombardment and indicates that comets are the dominant source of this dust rather than slower dust particles from asteroids.
The LADEE mission ended with its planned impact into the far side of the Moon in April 2014 at a speedy 3,600 miles per hour, destroying and probably vapourising it on impact.
Mysteries remain
For the origin of the glow seen on Apollo missions’, the team failed to find evidence of the relatively dense cloud of tiny dust particles lofted into the exosphere that would explain Apollo observations. In fact, the cloud the study recorded was 100 times less dense than the Apollo missions had predicted. Although disappointing for those seeking an explanation, this may be more positive for future human exploration missions or aspirations to use the Moon as a base for conducting sensitive astronomical observations, which require a clear view of the sky.
The result means that unless we want to dismiss the observations by the Apollo missions, we may need to re-assess our understanding of the conditions of the lunar surface and perhaps even the solar wind and resulting radiation field that was predicted to charge the dust and lift it into the atmosphere.
Washington (dpa) – A NASA spacecraft was on course on Tuesday to make a flyby within 520 kilometers of Saturn’s moon Dione – its fourth flyby since the spacecraft Cassini went into orbit around Saturn in 2004. A fifth flyby of Dione is planned for August, before Cassini’s final mission begins late this year. It will… Continue reading →
WASHINGTON, June 16, 2015 /PRNewswire-USNewswire/ — NASA and the United Nations Office for Outer Space Affairs (UNOOSA) have launched a global photography competition to highlight how the vantage point of space helps us better understand our home planet, improve lives, and safeguard our future by aiding sustainable development on Earth. To highlight the role of space-based… Continue reading →
