Life Could Be Evolving Right Now On Nearest Exoplanets

Rocky, Earth-like planets orbiting our closest stars could host life, according to a new study that raises the excitement about exoplanets.

When rocky, Earth-like planets were discovered orbiting in the habitable zone of some of our closest stars, excitement skyrocketed — until hopes for life were dashed by the high levels of radiation bombarding those worlds.

Proxima-b, only 4.24 light years away, receives 250 times more X-ray radiation than Earth and could experience deadly levels of ultraviolet radiation on its surface. How could life survive such a bombardment? Cornell University astronomers say that life already has survived this kind of fierce radiation, and they have proof: you.

Lisa Kaltenegger and Jack O’Malley-James make their case in a new paper, published in Monthly Notices of the Royal Astronomical Society. Kaltenegger is associate professor of astronomy and director of Cornell’s Carl Sagan Institute, at which O’Malley-James is a research associate.

All of life on Earth today evolved from creatures that thrived during an even greater UV radiation assault than Proxima-b, and other nearby exoplanets, currently endure. The Earth of 4 billion years ago was a chaotic, irradiated, hot mess. Yet in spite of this, life somehow gained a toehold and then expanded.

The same thing could be happening at this very moment on some of the nearest exoplanets, according to Kaltenegger and O’Malley-James. The researchers modeled the surface UV environments of the four exoplanets closest to Earth that are potentially habitable: Proxima-b, TRAPPIST-1e, Ross-128b and LHS-1140b.

These planets orbit small red dwarf stars which, unlike our sun, flare frequently, bathing their planets in high-energy UV radiation. While it is unknown exactly what conditions prevail upon the surface of the planets orbiting these flaring stars, it is known that such flares are biologically damaging and can cause erosion in planetary atmospheres. High levels of radiation cause biological molecules like nucleic acids to mutate or even shut down.

O’Malley-James and Kaltenegger modeled various atmospheric compositions, from ones similar to present-day Earth to “eroded” and “anoxic” atmospheres — those with very thin atmospheres that don’t block UV radiation well and those without the protection of ozone, respectively. The models show that as atmospheres thin and ozone levels decrease, more high-energy UV radiation reaches the ground. The researchers compared the models to Earth’s history, from nearly 4 billion years ago to today.

Although the modeled planets receive higher UV radiation than that emitted by our own sun today, this is significantly lower than what Earth received 3.9 billion years ago.

“Given that the early Earth was inhabited,” the researchers wrote, “we show that UV radiation should not be a limiting factor for the habitability of planets orbiting M stars. Our closest neighboring worlds remain intriguing targets for the search for life beyond our solar system.”

Iron Volcanoes May Have Erupted on Metal Asteroids

Metallic asteroids are thought to have started out as blobs of molten iron floating in space. As if that’s not strange enough, scientists now think that as the metal cooled and solidified, volcanoes spewing liquid iron could have erupted through a solid iron crust onto the surface of the asteroid.

This scenario emerged from an analysis by planetary scientists at UC Santa Cruz whose investigation was prompted in part by NASA’s plans to launch a probe to Psyche, the largest metallic asteroid in the solar system. Francis Nimmo, professor of Earth and planetary sciences, said he was interested in the composition of metallic asteroids indicated by analyses of iron meteorites, so he had graduate student Jacob Abrahams work on some simple models of how the asteroids cooled and solidified.

“One day he turned to me and said, ‘I think these things are going to erupt,'” Nimmo said. “I’d never thought about it before, but it makes sense because you have a buoyant liquid beneath a dense crust, so the liquid wants to come up to the top.”

The researchers described their findings in a paper that has been accepted for publication in Geophysical Research Letters.

Metallic asteroids originated early in the history of the solar system when planets were beginning to form. A protoplanet or “planetesimal” involved in a catastrophic collision could be stripped of its rocky outer layers, exposing a molten, iron-rich core. In the cold of space, this blob of liquid metal would quickly begin to cool and solidify.

As for what the iron volcanoes would look like, Abrahams said it depends on the composition of the melt. “If it’s mostly pure iron, then you would have eruptions of low-viscosity surface flows spreading out in thin sheets, so nothing like the thick, viscous lava flows you see on Hawaii,” he said. “At the other extreme, if there are light elements mixed in and gases that expand rapidly, you could have explosive volcanism that might leave pits in the surface.”

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Tracking Records Of The Oldest Life Forms On Earth

The discovery provides a new characteristic ‘biosignature’ to track the remains of ancient life preserved in rocks which are significantly altered over billions of years and could help identify life elsewhere in the Solar System.

The research, published in two papers — one in the Journal of the Geological Society and another in Earth and Planetary Science Letters — solves the longstanding problem of how scientists can track records of life on Earth in highly metamorphosed rocks more than 3,700 million years old, with organic material often turning into the carbon-based mineral graphite.

In the first study, published in Earth and Planetary Science Letters, the team analysed ten rock samples of banded iron formations (BIF) from Canada, India, China, Finland, USA and Greenland spanning over 2,000 million years of history.

They argue that carbon preserved in graphite-like crystals -‘graphitic carbon’- located alongside minerals such as apatite, which our teeth and bones are made of, and carbonate, are the biosignatures of the oldest life forms on Earth.

“Life on Earth is all carbon-based and over time, it decomposes into different substances, such as carbonate, apatite and oil. These become trapped in layers of sedimentary rock and eventually the oil becomes graphite during subsequent metamorphism in the crust,” explained Dr Dominic Papineau (UCL Earth Sciences, Center for Planetary Sciences and the London Centre for Nanotechnology).

“Our discovery is important as it is hotly debated whether the association of graphite with apatite is indicative of a biological origin of the carbon found in ancient rocks. We now have multiple strands of evidence that these mineral associations are biological in banded iron formations. This has huge implications for how we determine the origin of carbon in samples of extra-terrestrial rocks returned from elsewhere in the Solar System.”

The team investigated the composition of BIF rocks as they are almost always of Precambrian age (4,600 million years old to 541 million years old) and record information about the oldest environments on Earth.

For this, they analysed the composition of rocks ranging from 1,800 million years old to more than 3,800 million years old using a range of methods involving photons, electrons, and ions to characterise the composition of graphite and other minerals of potential biogenic origin.

“Previously, it was assumed that finding apatite and graphite together in ancient rocks was a rare occurrence but this study shows that it is commonplace in BIF across a range of rock metamorphic grades,” said team member Dr Matthew Dodd (UCL Earth Sciences and the London Centre for Nanotechnology).

The apatite and graphite minerals are thought to have two possible origins: mineralised products of decayed biological organic matter, which includes the breakdown of molecules in oil at high temperatures, or formation through non-biological reactions which are relevant to the chemistry of how life arose from non-living matter.

By showing evidence for the widespread occurrence of graphitic carbon in apatite and carbonate in BIF along with its carbon-isotope composition, the researchers conclude that the minerals are most consistent with a biological origin from the remains of Earth’s oldest life forms.

To investigate the extent to which high-temperature metamorphism causes a loss in molecular, elemental and isotope signatures from biological matter in rocks, they analysed the same minerals from a 1,850 million year old BIF rock in Michigan which had metamorphosed in 550 degree Celsius heat.

In this second study, published today in Journal of the Geological Society, the team show that several biosignatures are found in the graphitic carbon and the associated apatite, carbonate and clays.

They used a variety of high-tech instruments to detect traces of key molecules, elements, and carbon isotopes of graphite and combined this with several microscopy techniques to study tiny objects trapped in rocks which are invisible to the naked eye.

Together, all of their observations of the composition are consistent with an origin from decayed biomass, such as that of ancient animal fossils in museums, but which has been strongly altered by high temperatures.

“Our new data provide additional lines of evidence that graphite associated with apatite in BIF is most likely biological in origin. Moreover, by taking a range of observations from throughout the geological record, we resolve a long-standing controversy regarding the origin of isotopically light graphitic carbon with apatite in the oldest BIF,” said Dr Papineau.

“We’ve shown that biosignatures exist in highly metamorphosed iron formations from Greenland and northeastern Canada which are more than 3,850 million years old and date from the beginning of the sedimentary rock record.”

The work was kindly funded in part by NASA.

BREAKING NEWS: Scientists Set to Unveil First Picture of a Black Hole

On Wednesday, astronomers across the globe will hold “six major press conferences” simultaneously to announce the first results of the Event Horizon Telescope (EHT), which was designed precisely for that purpose.

Of all the forces or objects in the Universe that we cannot see – including dark energy and dark matter – none has frustrated human curiosity so much as the invisible digestive system that swallow stars like so many specks of dust.

“More than 50 years ago, scientists saw that there was something very bright at the center of our galaxy,” says Paul McNamara, an astrophysicist at the European Space Agency and an expert on black holes.

“It has a gravitational pull strong enough to make stars orbit around it very quickly – as fast as 20 years.”

To put that in perspective, our Solar System takes about 230 million years to circle the center of the Milky Way.

Eventually, astronomers speculated that these bright spots were in fact “black holes” – a term coined by American physicist John Archibald Wheeler in the mid-1960s – surrounded by a swirling band of white-hot gas and plasma.

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Science Of Cycles keeps you tuned-in and knowledgeable of what we are discovering, and how some of these changes will affect our communities and ways of living.

 

Large Antarctic Ice Shelf, Home To A UK Research Station, Is About To Break Apart

Glaciology experts have issued evidence that a large section of the Brunt Ice Shelf in Antarctica, which is home to the British Antarctic Survey’s Halley Research Station, is about break off.

The rifting started several years ago and is now approaching its final phase. In anticipation of the iceberg breaking away, the research station, which is currently unmanned, has been relocated to a safer location on the ice shelf, meaning there is no danger posed to personnel.

The iceberg, measuring over 1,500 square kilometres — which is twice the size of New York City — is expected to break away from the Brunt Ice Shelf in as little as a few months, when two large cracks which have been growing over the past seven years meet.

Now academics from Northumbria University, in Newcastle upon Tyne, UK, in collaboration with scientists from ENVEO, a remote sensing company in Austria, have submitted new research to the journal The Cryosphere, which shows that the break-off is part of the ice shelf’s natural lifecycle, and that similar events may have occurred in the past.

As Professor Hilmar Gudmundsson of Northumbria explains: “I have been carrying out research in this area for more than 15 years and have been monitoring the growth of the cracks since they first emerged in 2012.

“Satellite images of the changes in the ice shelf have been shared online and there has been much speculation about the cause of this movement and the impact the iceberg will have when it breaks away.

“However, what many people do not realise is that this is a natural process and something which has happened time and again. We recognise that climate change is a serious problem which is having an impact around the world, and particularly in the Antarctic. However, there is no indication from our research that this particular event is related to climate change.

“We have been tracking the movement of the ice shelf for many years and our modelling indicates that this breakaway is entirely expected. That is why in 2014 we recommended that the Halley Research Station was moved to a new and safe location on the ice shelf.

“Our field observations and modelling has meant that the station was safely relocated with no danger to the scientists using it and minimal disruption to the research taking place.”

The Brunt Ice Shelf is a large floating area of ice, around 150m to 250m thick, and is made up of freshwater ice which originally fell as snow further inland. The ice shelf rests on top of the Weddell Sea and flows off the mainland, moving outwards from the centre of Antarctica.

As ice shelves are afloat, any icebergs that form as a result of fractures in the ice do not contribute to sea level rise. “Once the iceberg breaks away from the Brunt Ice Shelf it is likely to drift towards the west and slowly break up into smaller icebergs,” explains Dr Jan De Rydt, also of Northumbria University.

This isn’t the first time a large piece of ice shelf has broken away in Antarctica. The Pine Island Ice Shelf in West Antarctica has seen several large sections break off in recent years, and the Larsen C Ice Shelf to the West of the Brunt Ice Shelf has lost a section more than 3,600 square miles due to calving — when ice chunks break from the edge of a glacier — in 2017.

And there is historic evidence to show the Brunt Ice Shelf has seen similar large calving events in the past. As Professor Gudmundsson explains: “Maps drawn by Shackleton and Wordie during their expedition to the Brunt Ice Shelf in 1915 show that, at that time, the ice shelf was quite extended. However, by the time the Halley Research Station was established in the 1950s the reach of the ice shelf was much shorter, indicating that a large iceberg must have broken away at some point after 1915. This further backs up our research that this type of event is historically consistent and part of the natural cycle and movement of the ice shelf.”

Dr De Rydt and Professor Gudmundsson’s paper, Calving cycle of the Brunt Ice Shelf, Antarctica, driven by changes in ice-shelf geometry, is currently undergoing peer review in the European Geosciences Union journal The Cryosphere.

The paper is co-authored by Thomas Nagler and Jan Wuite of ENVEO (Environmental Earth Observation), in Innsbruck, Austria, who have worked closely with Professor Gudmundsson and Dr De Rydt during the research. ENVEO is a world-leader in processing satellite data for monitoring changes in the global snow and ice cover. The two teams have been collaborating together for several years on a number of projects, with scientists from ENVEO using satellite imagery to extract data about the changing speed of the ice shelf, which is then shared with researchers at Northumbria University for modelling and interpretation.

Dr Jan Wuite of ENVEO said: “Thanks to the Copernicus Sentinel-1 and Sentinel-2 satellites we can now continuously monitor the movement of the ice shelf and the propagation of the cracks in great detail and in near real-time. These observational data are very useful for improving existing ice flow models.”

Dr Thomas Nagler of ENVEO added: “This work is the result of the long-lasting partnership between the glaciologists from Northumbria University and remote sensing experts from ENVEO, that has already led to several previous publications on Brunt Ice Shelf.”

My Two Girls Are Growing Up

Hi Folks, I know some of you like to keep up with my family, especially my two girls. Well, they are growing up faster than I would like or really prepared for – which is probably echoed by parents around the world. Sophia is now 7 yrs old and her hair is about as long as she is. Alexa just turned 11yrs and her pre-teen changes are both exciting and terrifying.

I am having to dig into the books (actually online) to understand the hormonal changes, which of course goes along with her physical changes. She is a beauty (of course every dad would say this) but she really really is…and her smarts are as sharp as her looks. (well, I guess every dad says this too). Uhh, I thought going through a Peer Review was herculean challenge.

I know some of you like to share gifts for them, so I will put a link below if you wish to. Sophia’s birthday was just a month ago, and Alexa’s is this week. If you have a specific gift you wish to present for either of them, just write it down in an email and I will make sure we get it for them.

Lots of news coming out related to charged particles and their influence on our solar system and of course our home Earth. As research commonly ensues, most of the current published papers reflect data collected over the past year, or at times few years, but then there are some new revelations which have occurred in the last few days and weeks.

Stay tuned for a few surprises and some that affirm our research….
Cheers, Mitch

 

Japan Probe Prepares to Blast Asteroid from Hayabusa2

A Japanese probe began descending towards an asteroid on Thursday on a mission to blast a crater into its surface and collect material that could shed light on the solar system’s evolution.

The mission will be the latest in a series of explorations carried out by the Japanese space agency’s Hayabusa2 probe and could reveal more about the origin of life on Earth.

But the task scheduled for Friday will be the riskiest yet of Hayabusa2’s investigations, and involves the release of a device filled with explosives.

The so-called “small carry-on impactor”, a cone-shaped device capped with a copper bottom, will emerge from Hayabusa2 on Friday, after the probe has arrived just 500 meters above the asteroid Ryugu.

The probe will then depart the area, and the impactor is programmed to explode 40 minutes later, propelling the copper bottom towards Ryugu, where it should gouge a crater into the surface of the asteroid that sits 300 million kilometers from Earth.

Hayabusa2 will move away from the area to avoid being damaged by debris from the explosion or the collision with Ryugu.

As it does so it will release a camera slightly above the site of the detonation that should be able to capture images of the event.