Long After Humanity is Gone and the Sun Dies, the Water Bears Will be There

Like all living creatures, stars have a natural lifespan. After going through their main sequence phase, they eventually exhaust their nuclear fuel and begin the slow process towards death. In our Sun’s case, this will consist of it growing in size and entering the Red Giant phase of its evolution. When that happens, roughly 5.4 billion years from now, the Sun will encompass the orbit’s of Mercury, Venus, and maybe even Earth.

However, even before this happens, astronomers theorize that the Sun will dramatically heat up, which will render Earth uninhabitable to most species. But according to a new study by a team of researchers from Oxford and the University of Harvard, the species known as tardigrades (aka. the “water bear”) will likely survive even after humanity and all other species have perished.

This study, which was recently published in the journal Scientific Reports under the titleThe Resilience of Life to Astrophysical Events“, was conducted by Dr. David Sloan, Dr. Rafael Alves Batista – from the Department of Astrophysics at Oxford University – and Dr. Abraham Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA). As they indicate, previous studies into the effect Solar evolution will have on life have been rather lopsided.

Earth scorched by red giant Sun
Artist’s impression of the Earth scorched by our Sun as it enters its Red Giant Branch phase. Credit: Wikimedia Commons/Fsgregs

Essentially, much attention has been dedicated to whether or not humanity will survive our Sun leaving its main sequence phase. Comparatively, very little research has been conducted on whether or not life itself (and which lifeforms) will be able to survive this change. As such, they considered the most statistically-likely events that would be capable of completely sterilizing an Earth-like planet, and sought to determine what lifeforms could endure them.

As Dr. Loeb told Universe Today via email, their team wanted to consider if there was an extinction-level event that could eliminate all life on Earth (not just humans):

“We wanted to find out how long life may survive on a planet once formed. Most previous studies focused on the survival of humans which are very sensitive to changes in the atmosphere or climate of the Earth and can be eliminated by the impact of an asteroid (nuclear winter) or bad politics.”

What they found was that the species Milnesium tardigradum would survive all potential astrophysical catastrophes. What’s more, they estimated that these creatures will be around for another 10 billion years at least – far longer than what is anticipated for the human race! As Loeb indicates, this was not an outcome that they were expecting.

“To our surprise, tardigrades are likely to survive all astrophysical catastrophes,” he said. “Most likely, the DNA of tardigrades is able to repair itself quickly due to damage encountered by the environment. The process is not fully understood, and there is a group at Harvard University who studies the SNA of tardigrades with the hope of understanding it better.”

Scanning Electron Microscope (SEM) image of Milnesium tardigradum in active state. Credit: Schokraie E/Warnken U/Hotz-Wagenblatt A/Grohme MA/Hengherr S, et al.

To be fair, it has been known for some time that Tardigrades are the most resilient life form on Earth. Not only can they survive for up to 30 years without food or water (half their natural lifespan), they can also survive temperatures of up to 150 °C (302 °F) and as low as -200 °C (-328 °F). They have also shown themselves to be capable of enduring extremes in pressure, ranging from the 6000 atmospheres to the vacuum of open space.

Under these conditions, the research team concluded that they are likely to survive the Sun becoming a red giant and irradiating Earth, and will likely be alive even after the Sun has winked out of existence.  On top of that, tardigrades can even be brought back to life, under the right circumstances. Much like all life on Earth, tradigrades need water to survive, even though they can survive in a dry state for extended periods of time – up to ten years, in fact.

But even after being deprived of water to the point of death, scientists have found that these organisms can be reanimated once water is reintroduced. This was demonstrated in 2007 when a batch of tardigrades was dehydrated before being launched to Low Earth Orbit (LEO). After being exposed to the hard vacuum of space and UV radiation for 10 days, they were returned to Earth and rehydrated – at which point, the majority were revived and able to produce viable embryos.

The team also concluded that other cataclysmic events – such as an asteroid strike, exploding stars (i.e. a supernovae) or gamma ray bursts – pose no existential threat to tardigrades. As Loeb explained:

“We have found that asteroid impacts are capable of boiling off all the oceans on Earth, but only if the asteroid is more massive than 1018 kg [10,000 trillion metric tons]. Such events are extremely rare and will not happen before the Sun will die; the probability of them happening earlier is less than one part in a million.”

Artist’s concept of a collision between proto-Earth and Theia, believed to happened 4.5 billion years ago. Credit: NASA

In fact, the last time an object large enough to boil the oceans (2 x 1018 kg) collided with Earth occurred roughly 4.51 billion years ago. On this occasion, Earth was struck by a Mars-sized object named Theia, which is believed to be what caused the formation of the Moon. Today, there are only a dozen known asteroids or dwarf planets in the Solar System that have this kind of mass, and none of them will intersect the Earth’s orbit in the future.

As for supernova, they indicated that an exploding star would need to be 0.14 light-years from Earth in order for it to boil the oceans from its surface. Since the closest star to our Sun (Proxima Centauri) is 4.25  light years away, this scenario is not a foreseeable risk. As for gamma-ray bursts, which are even rarer than supernova, the team determined that they too are too far away from Earth to pose a threat.

The implications of this study are quite fascinating. For one, it reminds us just how fragile human life is compared to basic, microscopic life forms. It also demonstrates that similarly hardy organisms could exist in a variety of locations that we may have once considered too hostile for life. As Dr Rafael Alves Batista, one of the co-authors on the study, said in a University of Oxford press release:

“Without our technology protecting us, humans are a very sensitive species. Subtle changes in our environment impact us dramatically. There are many more resilient species’ on earth. Life on this planet can continue long after humans are gone. Tardigrades are as close to indestructible as it gets on Earth, but it is possible that there are other resilient species examples elsewhere in the Universe. In this context there is a real case for looking for life on Mars and in other areas of the Solar System in general. If Tardigrades are earth’s most resilient species, who knows what else is out there?’”

The tiny Tardigrade: Nature's toughest creature? (Image Credit: Katexic Publications, unaltered, CC2.0)
The tiny Tardigrade: Nature’s toughest creature? Credit: Katexic Publications, unaltered, CC2.0)

And as Dr. Loeb explained, studies like this have potential benefits that go far beyond assessing our own survivability. Not only do they help us understand life’s ability to endure catastrophic events – which is essential to understanding how and where life could emerge in the Universe – but they also offer possibilities on how we might better our own chances of survival.

“We get a better understanding of the conditions under which life will persist,” he said. “In about a billion years, when the Sun will heat up life will cease, but until then it will continue in some form. Understanding the self-repair mechanism of the DNA on tardigrades could potentially help in combating disease for humans as well.”

And all his time, we thought cockroaches were the toughest critters on the planet, what with their ability to withstand a nuclear holocaust. But these eight-legged creatures, which are arguably cuter than cockroaches too, clearly have the market on toughness cornered. We’re just lucky they only get up to 0.5 mm (0.02 in) in size, otherwise we might have something to worry about!

Further Reading: University of Oxford, Scientific Reports

Trump Proposes $19.1 Billion 2018 NASA Budget, Cuts Earth Science and Education

NASA acting administrator Robert Lightfoot outlines NASA’s Fiscal Year 2018 budget proposal during a ‘State of NASA’ speech to agency employees held at NASA HQ on May 23, 2017. Credit: NASA TV/Ken Kremer

The Trump Administration has proposed a $19.1 Billion NASA budget request for Fiscal Year 2018, which amounts to a $0.5 Billion reduction compared to the recently enacted FY 2017 NASA Budget. Although it maintains many programs such as human spaceflight, planetary science and the Webb telescope, the budget also specifies significant cuts and terminations to NASA’s Earth Science and manned Asteroid redirect mission as well as the complete elimination of the Education Office.

Overall NASA’s FY 2018 budget is cut approximately 3%, or $560 million, for the upcoming fiscal year starting in October 2017 as part of the Trump Administration’s US Federal Budget proposal rolled out on May 23, and quite similar to the initial outline released in March.

The cuts to NASA are smaller compared to other Federal science agencies also absolutely vital to the health of US scientific research – such as the NIH, the NSF, the EPA, DOE and NIST which suffer unconscionable double digit slashes of 10 to 20% or more.

The highlights of NASA’s FY 2018 Budget were announced by NASA acting administrator Robert Lightfoot during a ‘State of NASA’ speech to agency employees held at NASA HQ, Washington, D.C. and broadcast to the public live on NASA TV.

Lightfoot’s message to NASA and space enthusiasts was upbeat overall.

“What this budget tells us to do is to keep going!” NASA acting administrator Robert Lightfoot said.

“Keep doing what we’ve been doing. It’s very important for us to maintain that course and move forward as an agency with all the great things we’re doing.”

“I want to reiterate how proud I am of all of you for your hard work – which is making a real difference around the world. NASA is leading the world in space exploration, and that is only possible through all of your efforts, every day.”

“We’re pleased by our top line number of $19.1 billion, which reflects the President’s confidence in our direction and the importance of everything we’ve been achieving.”

Lightfoot recalled the recent White House phone call from President Trump to NASA astronaut & ISS Station Commander Peggy Whitson marking her record breaking flight for the longest cumulative time in space by an American astronaut.

Thus Lightfoot’s vision for NASA has three great purposes – Discover, Explore, and Develop.

“NASA has a historic and enduring purpose. It can be summarized in three major strategic thrusts: Discover, Explore, and Develop. These correspond to our missions of scientific discovery, missions of exploration, and missions of new technology development in aeronautics and space systems.”

Lightfoot further recounted the outstanding scientific accomplishments of NASA’s Mars rover and orbiters paving the path for the agencies plans to send humans on a ‘Journey to Mars’ in the 2030s.

“We’ve had a horizon goal for some time now of reaching Mars, and this budget sustains that work and also provides the resources to keep exploring our solar system and look beyond it.”

Lightfoot also pointed to upcoming near term science missions- highlighting a pair of Mars landers – InSIGHT launching next year as well as the Mars 2020 rover. Also NASA’s next great astronomical observatory – the James Webb Space Telescope (JWST).

“In science, this budget supports approximately 100 missions: 40 missions currently preparing for launch & 60 operating missions.”

“The James Webb Space Telescope is built!” Lightfoot gleefully announced.

“It’s done testing at Goddard and now has moved to Johnson for tests to simulate the vacuum of space.”

JWST is the scientific successor to the Hubble Space Telescope and slated for launch in Oct. 2018. The budget maintains steady support for Webb.

The 18-segment gold coated primary mirror of NASA’s James Webb Space Telescope is raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on Nov. 2, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com

The Planetary Sciences division receives excellent support with a $1.9 Billion budget request. It includes solid support for the two flagship missions – Mars 2020 and Europa Clipper as well as the two new Discovery class missions selected -Lucy and Psyche.

“The budget keeps us on track for the next selection for the New Frontiers program, and includes formulation of a mission to Jupiter’s moon Europa.”

SLS and Orion are making great progress. They are far beyond concepts, and as I mentioned, components are being tested in multiple ways right now as we move toward the first flight of that integrated system.”

NASA is currently targeting the first integrated launch of SLS and Orion on the uncrewed Exploration Mission-1 (EM-1) for sometime in 2019.

Top NASA managers recently decided against adding a crew of two astronauts to the flight after conducting detailed agency wide studies at the request of the Trump Administration.

NASA would have needed an additional $600 to $900 to upgrade EM-1 with humans.

Unfortunately Trump’s FY 2018 NASA budget calls for a slight reduction in development funding for both SLS and Orion – thus making a crewed EM-1 flight fiscally unviable.

The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

The budget request does maintain full funding for both of NASA’s commercial crew vehicles planned to restore launching astronauts to low Earth orbit (LEO) and the ISS from US soil on US rockets – namely the crewed Dragon and CST-100 Starliner – currently under development by SpaceX and Boeing – thus ending our sole reliance on Russian Soyuz for manned launches.

“Working with commercial partners, NASA will fly astronauts from American soil on the first new crew transportation systems in a generation in the next couple of years.”

“We need commercial partners to succeed in low-Earth orbit, and we also need the SLS and Orion to take us deeper into space than ever before.”

Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com

However the Trump Administration has terminated NASA’s somewhat controversial plans for the Asteroid Redirect Mission (ARM) – initiated under the Obama Administration – to robotically retrieve a near Earth asteroid and redirect it to lunar orbit for a visit by a crewed Orion to gather unique asteroidal samples.

“While we are ending formulation of a mission to an asteroid, known as the Asteroid Redirect Mission, many of the central technologies in development for that mission will continue, as they constitute vital capabilities needed for future human deep space missions.”

Key among those vital capabilities to be retained and funded going forward is Solar Electric Propulsion (SEP).

“Solar electric propulsion (SEP) for our deep space missions is moving ahead as a key lynchpin.”

The Trump Administration’s well known dislike for Earth science and disdain of climate change has manifested itself in the form of the termination of 5 current and upcoming science missions.

NASA’s FY 2018 Earth Science budget suffers a $171 million cut to $1.8 Billion.

“While we are not proposing to move forward with Orbiting Carbon Observatory-3 (OCO-3), Plankton, Aerosol, Cloud, ocean Ecosystem (PACE), Climate Absolute Radiance and Refractivity Observatory Pathfinder (CLARREO PF), and the Radiation Budget Instrument (RBI), this budget still includes significant Earth Science efforts, including 18 Earth observing missions in space as well as airborne missions.”

The DSCOVR Earth-viewing instruments will also be shut down.

NASA’s Office of Education will also be terminated completely under the proposed FY 2018 budget and the $115 million of funding excised.

“While this budget no longer supports the formal Office of Education, NASA will continue to inspire the next generation through its missions and the many ways that our work excites and encourages discovery by learners and educators. Let me tell you, we are as committed to inspiring the next generation as ever.”

Congress will now have its say and a number of Senators, including Republicans says Trumps budget is DOA.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Bound for Bennu, OSIRIS-REx Begins Trailblazing Asteroid Sampling Sortie for Life’s Origins – Sunset Launch Gallery

United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study.  Liftoff was at 7:05 p.m. EDT on September 8, 2016 in this remote camera view taken from inside the launch pad perimeter.  Note the newly install crew access arm and white room for astronaut flights atop Atlas starting in early 2018.   Credit: Ken Kremer/kenkremer.com
United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. Liftoff was at 7:05 p.m. EDT on September 8, 2016 in this remote camera view taken from inside the launch pad perimeter. Note the newly installed crew access arm and white room for astronaut flights atop Atlas starting in early 2018. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – Bound for Bennu, NASA’s OSIRIS-REx robotic explorer began a trailblazing 7 year round trip sampling sortie on Sept. 8 in search of the origin of life with a spectacular sky show – thrilling spectators ringing the Florida Space Coast.

Hordes of space enthusiasts from all across the globe descended on the Kennedy Space Center and Cape Canaveral region for the chance of a lifetime to witness a once in a lifetime liftoff to the carbon rich asteroid – which could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.

NASA’s Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer (OSIRIS-REx) spacecraft departed Earth with an on time engine ignition of a United Launch Alliance Atlas V rocket under crystal clear skies on Thursday, September 8 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station.

Blastoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach.  Credit: Jillian Laudick
Blastoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach. Credit: Jillian Laudick

Everything went exactly according to plan for the daring mission bolding seeking to gather rocks and soil from Bennu – using an ingenious robotic arm named TAGSAM – and bring at least a 60-gram (2.1-ounce) sample back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.

“We got everything just exactly perfect,” said Dante Lauretta, the principal investigator for OSIRIS-REx at the University of Arizona, at the post launch briefing at the Kennedy Space Center. “We hit all our milestone within seconds of predicts.

The space rock measures about the size of a small mountain at about a third of a mile in diameter.

And the picture perfect near sunset launch rewarded photographers from near and far with a spectacular series of richly hued photo and video recordings.

So I’ve gathered here a variety of launch imagery from multiple vantage points shot by friends, colleagues and myself – for the enjoyment of readers of Universe Today and Beyond!

Liftoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL.  Credit: Julian Leek
Liftoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL. Credit: Julian Leek

As you’ll see and hear the ULA Atlas V rocket integrated with OSIRIS-Rex on top thundered off the Cape’s pad 41 and shot skyward straight up along an equatorial path into Florida’s sun.

From every vantage point the rocket and its ever expanding vapor trail were visible for some 4 or 5 minutes or more. From my location on the roof of NASA’s Vehicle Assembly Building (VAB) the rocket finally arched over nearly straight above us and the sun produced a magnificent thin and nearly straight shadow of the vapor trail on the ground running out to the Atlantic Ocean towards Africa.

Blastoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach.  Credit: John Kraus
Blastoff of NASA’s OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach. Credit: John Kraus

It was truly an unforgettable sight to behold. And folks at Playalinda Beach, the best public viewing spot just a few miles north of pad 40 had an uninhibited view of the rocket to the base of the pad – while they waded and swam in the oceans waters with waves crashing on shore as the Atlas rocket blasted to space.

OSIRIS-REx separated as planned from the Atlas V rockets liquid oxygen and liquid hydrogen fueled second stage rocket to fly free at 8:04 p.m. on Sept. 8 – 55 minutes after launch.

The pair of solar arrays deployed as planned to provide the probes life giving power.

The spacecraft was built by prime contractor Lockheed.

“The spacecraft is healthy and functioning properly,” Richard Kuhns, Lockheed Martin OSIRIS-REx program manager, told me in an interview at the post-launch briefing.

Members of the OSIRIS-REx mission team celebrate the successful spacecraft launch on Sept. 8, 2016 atop ULA Atlas V at the post-launch briefing at the Kennedy Space Center, FL. Principal Investigator Dante Lauretta is 4th from right,  NASA Planetary Science Director Jim Green is center, 5th from left. Credit: Ken Kremer/kenkremer.com
Members of the OSIRIS-REx mission team celebrate the successful spacecraft launch on Sept. 8, 2016 atop ULA Atlas V at the post-launch briefing at the Kennedy Space Center, FL. Principal Investigator Dante Lauretta is 4th from right, NASA Planetary Science Director Jim Green is center, 5th from left. Richard Kuhns, Lockheed Martin OSIRIS-REx program manager, 2nd from right. Credit: Ken Kremer/kenkremer.com

“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu, OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final preparations for shipment to the launch pad.

“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”

“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”

The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.

After a two year flight through space, including an Earth swing by for a gravity assisted speed boost in 2017, OSIRIS-REx will reach Bennu in Fall 2018 to begin about 2 years of study in orbit to determine the physical and chemical properties of the asteroid in extremely high resolution.

While orbiting Bennu starting in 2018 it will move in close to explore the asteroid for about two years with its suite of science instruments, scanning in visible and infrared light. After a thorough site selection, it will move carefully towards the surface and extend the 11 foot long TAGSAM robotic arm and snatch pristine soil samples containing organic materials from the surface using the TAGSAM collection dish over just 3 to 5 seconds.

Once a good sample collection is confirmed, the dish will then be placed inside the Earth return canister and be brought back to Earth for study by researchers using all of the most sophisticated science instruments available to humankind.

Using the 11 foot long TAGSAM robotic arm that functions somewhat like a pogo stick, OSIRIS-REx will gather rocks and soil and bring at least a 60-gram (2.1-ounce) sample back to Earth on Sept 24, 2023. It has the capacity to scoop up to about 2 kg or more.

ULA Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s OSIRIS-REx asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL, in this remote camera view taken from inside the launch pad perimeter.  Credit: Ken Kremer/kenkremer.com
ULA Atlas V rocket lifts off on September 8, 2016 from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s OSIRIS-REx asteroid sampling spacecraft, in this remote camera view taken from inside the launch pad perimeter. Credit: Ken Kremer/kenkremer.com

The two stage ULA Atlas V performed flawlessly and delivered OSIRIS-Rex into a hyperbolic trajectory away from Earth.

The 189 foot tall ULA Atlas V rocket launched in the rare 411 configuration for only the 3rd time on this mission – which is the 65th for the Atlas V.

The Atlas 411 vehicle includes a 4-meter diameter large Payload Fairing (PLF) and one solid rocket booster that augments the first stage. The Atlas booster for this mission is powered by the RD AMROSS RD-180 engine and the Centaur upper stage was powered by the Aerojet Rocketdyne RL10A.

The RD-180 burns RP-1 (Rocket Propellant-1 or highly purified kerosene) and liquid oxygen and delivers 860,200 lb of thrust at sea level.

The strap on solid delivers approximately 348,500 pounds of thrust.

The Centaur delivers 22, 230 lbf of thrust and burns liquid oxygen and liquid hydrogen.

The solid was jettisoned at 139 seconds after liftoff.

Launch of NASA’s OSIRIS-REx on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from LC-39 Gantry.  Credit: Jen Saxby
Launch of NASA’s OSIRIS-REx on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from LC-39 Gantry. Credit: Jen Saxby

This is ULA’s eighth launch in 2016 and the 111th successful launch since the company was formed in December 2006.

NASA’s OSIRIS-REx blasts off to asteroid Bennu on ULA Atlas V rocket prior on Sept. 8, 2016 from Space Launch Complex 41 on Cape Canaveral Air Force Station, FL, as seen from the VAB roof.  Credit: Lane Hermann/SpaceHeadNews
NASA’s OSIRIS-REx blasts off to asteroid Bennu on ULA Atlas V rocket prior on Sept. 8, 2016 from Space Launch Complex 41 on Cape Canaveral Air Force Station, FL, as seen from the VAB roof. Credit: Lane Hermann/SpaceHeadNews

OSIRIS-REx will return the largest sample from space since the American and Soviet Union’s moon landing missions of the 1970s.

Watch these pair of up close videos (from myself and Jeff Seibert) captured directly at the pad with the sights and sounds of the fury of launch:

Video Caption: ULA Atlas V rocket lifts off on September 8, 2016 from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s OSIRIS-REx asteroid sampling spacecraft, in this remote camera view taken from inside the launch pad perimeter. Credit: Ken Kremer/kenkremer.com

Video Caption: Compilation of my launch videos from the ULA Atlas 5 launch in support of the NASA OSIRIS_REx asteroid sample return mission to the asteroid Bennu (#101955). It was launched on September 8th, 2016 from Pad 41 of CCAFS. It is scheduled to land in UTAH with asteroid samples on September 24, 2023. Credit: Jeff Seibert

OSIRIS-REx is the third mission in NASA’s New Frontiers Program, following New Horizons to Pluto and Juno to Jupiter, which also launched on Atlas V rockets.

NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is responsible for overall mission management.

OSIRIS-REx complements NASA’s Asteroid Initiative – including the Asteroid Redirect Mission (ARM) which is a robotic spacecraft mission aimed at capturing a surface boulder from a different near-Earth asteroid and moving it into a stable lunar orbit for eventual up close sample collection by astronauts launched in NASA’s new Orion spacecraft. Orion will launch atop NASA’s new SLS heavy lift booster concurrently under development.

Launch of NASA’s OSIRIS-REx on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from VAB roof.  Credit:  J.Sekora/SEKORAPHOTO
Launch of NASA’s OSIRIS-REx on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from VAB roof. Credit: J.Sekora/SEKORAPHOTO

Watch for Ken’s continuing OSIRIS-REx mission and launch reporting from on site at the Kennedy Space Center and Cape Canaveral Air Force Station, FL.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

NASA’s OSIRIS-Rex asteroid sampling spacecraft streaks to orbit on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach.  Credit: Jillian Laudick
NASA’s OSIRIS-Rex asteroid sampling spacecraft streaks to orbit on September 8, 2016 from Cape Canaveral Air Force Station, FL as seen from Playalinda Beach. Credit: Jillian Laudick
Liftoff of NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL.  Credit: Ken Kremer/kenkremer.com
Liftoff of NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-Rex asteroid sampling spacecraft on September 8, 2016 from Cape Canaveral Air Force Station, FL. Credit: Ken Kremer/kenkremer.com
A United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study.  Liftoff was at 7:05 p.m. EDT on September 8, 2016.  Credit: Ken Kremer/kenkremer.com
A United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx spacecraft on the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. Liftoff was at 7:05 p.m. EDT on September 8, 2016. Credit: Ken Kremer/kenkremer.com
View of science instrument suite and TAGSAM robotic sample return arm on NASA’s OSIRIS-REx asteroid sampling spacecraft inside the Payloads Hazardous Servicing Facility at NASA's Kennedy Space Center.  Probe is slated for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral Air Force Station, FL.  Credit: Ken Kremer/kenkremer.com
View of science instrument suite and TAGSAM robotic sample return arm on NASA’s OSIRIS-REx asteroid sampling spacecraft inside the Payloads Hazardous Servicing Facility at NASA’s Kennedy Space Center. Probe is slated for Sep. 8, 2016 launch to asteroid Bennu from Cape Canaveral Air Force Station, FL. Credit: Ken Kremer/kenkremer.com

A History Of Violence: Iron Found in Fossils Suggests Supernova Role In Mass Dying

Space and events that transpire there directly affect our lives and those of our remote ancestors. Credit: Bob King
Space and events that transpire there directly affect our lives and those of our remote ancestors including early humans who walked the planet two million years ago. Credit: Bob King

Outer space touches us in so many ways. Meteors from ancient asteroid collisions and dust spalled from comets slam into our atmosphere every day, most of it unseen. Cosmic rays ionize the atoms in our upper air, while the solar wind finds crafty ways to invade the planetary magnetosphere and set the sky afire with aurora. We can’t even walk outside on a sunny summer day without concern for the Sun’s ultraviolet light burning out skin.

So perhaps you wouldn’t be surprised that over the course of Earth’s history, our planet has also been affected by one of the most cataclysmic events the universe has to offer: the explosion of a supergiant star in a Type II supernova event. After the collapse of the star’s core, the outgoing shock wave blows the star to pieces, both releasing and creating a host of elements. One of those is iron-60. While most of the iron in the universe is iron-56, a stable atom made up of 26 protons and 30 neutrons, iron-60 has four additional neutrons that make it an unstable radioactive isotope.

Crab Nebula from NASA's Hubble Space Telescope
The Crab Nebula, shown here in this image from NASA’s Hubble Space Telescope, is the expanding cloud of gas and dust left after a massive star exploded as a supernova in 1054. Supernovae propel a star’s innards back into space while creating new radioactive isotopes such as iron-60. Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)

If a supernova occurs sufficiently close to our Solar System, it’s possible for some of the ejecta to make its way all the way to Earth. How might we detect these stellar shards? One way would be to look for traces of unique isotopes that could only have been produced by the explosion. A team of German scientists did just that. In a paper published earlier this month in the Proceedings of the National Academy of Sciences, they report the detection of iron-60 in biologically produced nanocrystals of magnetite in two sediment cores drilled from the Pacific Ocean.

Magnetite is an iron-rich mineral naturally attracted to a magnet just as a compass needle responds to Earth’s magnetic field. Magnetotactic bacteria, a group of bacteria that orient themselves along Earth’s magnetic field lines, contain specialized structures called magnetosomes, where they store tiny magnetic crystals – primarily as magnetite (or greigite, an iron sulfide) in long chains. It’s thought nature went to all this trouble to help the creatures find water with the optimal oxygen concentration for their survival and reproduction. Even after they’re dead, the bacteria continue to align like microscopic compass needles as they settle to the bottom of the ocean.

These are transmission electron microscope images showing tiny magnetofossils left by bacteria about 2.5 million years ago.
These are transmission electron microscope images showing tiny magnetofossils containing iron-60, a form of iron produced during the violent explosion and death of a massive star in a supernova. They were deposited by bacteria in sediments found on the floor of the Pacific Ocean. Click for more details. Credit: courtesy Marianne Hanzlik, Chemie Department, FG Elektronenmikroskopie, Technische Universität München

After the bacteria die, they decay and dissolve away, but the crystals are sturdy enough to be preserved as chains of magnetofossils that resemble beaded garlands on the family Christmas tree. Using a mass spectrometer, which teases one molecule from another with killer accuracy, the team detected “live” iron-60 atoms in the fossilized chains of magnetite crystals produced by the bacteria. Live meaning still fresh. Since the half-life of iron-60 is only 2.6 million years, any primordial iron-60 that seeded the Earth in its formation has long since disappeared. If you go digging around now and find iron-60, you’re likely looking at at a supernova as the smoking gun.

Co-authors Peter Ludwig and Shawn Bishop, along with the team, found that the supernova material arrived at Earth about 2.7 million years ago near the boundary of the Pleistocene and Pliocene epochs and rained down for all of 800,000 years before coming to an end around 1.7 million years ago. If ever a hard rain fell.

Reconstruction of Homo habilis at the Westfälisches Museum für Archäologie. Credit: Lillyundfreya / Wikipedia
Reconstruction of Homo habilis at the Westfälisches Museum für Archäologie. Credit: Lillyundfreya / Wikipedia

The peak concentration occurred about 2.2 million years ago, the same time our early human ancestors, Homo habilis, were chipping tools from stone. Did they witness the appearance of a spectacularly bright “new star” in the night sky? Assuming the supernova wasn’t obscured by cosmic dust, the sight must have brought our bipedal relations to their knees.

There’s even a possibility that an increase in cosmic rays from the event affected our atmosphere and climate and possibly led to a minor die-off at the time. Africa’s climate dried out and repeated cycles of glaciation became common as global temperatures continued their cooling trend from the Pliocene into the Pleistocene.

Cosmic rays strike our atmosphere all the time, but their energy is spent creating showers of secondary, less energetic particles. Credit: Simon Swordy, University of Chicago, NASA
Cosmic rays strike our atmosphere all the time, but their energy is spent striking atoms to create showers of secondary, less energetic particles, a few of which sometimes make it to the ground. Credit: Simon Swordy, University of Chicago, NASA

Cosmic rays, which are extremely fast-moving, high-energy protons and atomic nucleic, rip up molecules in the atmosphere and can even penetrate down to the surface during a nearby supernova explosion, within about 50 light years of the Sun. The high dose of radiation would put life at risk, while at the same time providing a surge in the number of mutations, one of the creative forces driving the diversity of life over the history of our planet. Life — always a story of taking the good with the bad.

The discovery of iron-60 further cements our connection to the universe at large. Indeed, bacteria munching on supernova ash adds a literal twist to the late Carl Sagan’s famous words: “The cosmos is within us. We are made of star-stuff.” Big or small, we owe our lives to the synthesis of elements within the bellies of stars.

Bio-Mimicry and Space Exploration

A close-up of the spiral pattern in a sunflower. (Image Credit: Vishwas Krishna, unaltered, CC2.0)

“Those who are inspired by a model other than Nature, a mistress above all masters, are laboring in vain.

-Leonardo DaVinci

What DaVinci was talking about, though it wasn’t called it at the time, was biomimicry. Biomimicry is the practice of using designs from the natural world to solve technological and engineering problems. Were he alive today, there’s no doubt that Mr. DaVinci would be a big proponent of biomimicry.

Nature is more fascinating the deeper you look into it. When we look deeply into nature, we’re peering into a laboratory that is over 3 billion years old, where solutions to problems have been implemented, tested, and revised over the course of evolution. That’s why biomimicry is so elegant: on Earth, nature has had more than 3 billion years to solve problems, the same kinds of problems we need to solve to advance in space exploration.

The more powerful our technology gets, the deeper we can see into nature. As greater detail is revealed, more tantalizing solutions to engineering problems present themselves. Scientists who look to nature for solutions to engineering and design problems are reaping the rewards, and are making headway in several areas related to space exploration.

Continue reading “Bio-Mimicry and Space Exploration”

Is There a Kraken in Kraken Mare? What Kind of Life Would We Find on Titan?

The left image shows a mosaic of images of Titan taken by the Cassini spacecraft in near infrared light. Titan’s polar seas are visible as sunlight glints off of them. The right image is a radar image of Kraken Mare. Credit: NASA Jet Propulsion Laboratory.

Could there be life on Saturn’s large moon Titan? Asking the question forces astrobiologists and chemists to think carefully and creatively about the chemistry of life, and how it might be different on other worlds than it is on Earth. In February, a team of researchers from Cornell University, including chemical engineering graduate student James Stevenson, planetary scientist Jonathan Lunine, and chemical engineer Paulette Clancy, published a pioneering study arguing that cell membranes could form under the exotic chemical conditions present on this remarkable moon.

In many ways, Titan is Earth’s twin. It’s the second largest moon in the solar system and bigger than the planet Mercury. Like Earth, it has a substantial atmosphere, with a surface atmospheric pressure a bit higher than Earth’s. Besides Earth, Titan is the only object in our solar system known to have accumulations of liquid on its surface. NASA’s Cassini space probe discovered abundant lakes and even rivers in Titan’s polar regions. The largest lake, or sea, called Kraken Mare, is larger than Earth’s Caspian Sea. Researchers know from both spacecraft observations and laboratory experiments that Titan’s atmosphere is rich in complex organic molecules, which are the building blocks of life.

All these features might make it seem as though Titan is tantalizingly suitable for life. The name ‘Kraken’, which refers to a legendary sea monster, fancifully reflects the eager hopes of astrobiologists. But, Titan is Earth’s alien twin. Being almost ten times further from the sun than Earth is, its surface temperature is a frigid -180 degrees Celsius. Liquid water is vital to life as we know it, but on Titan’s surface all water is frozen solid. Water ice takes on the role that silicon-containing rock does on Earth, making up the outer layers of the crust.

The liquid that fills Titan’s lakes and rivers is not water, but liquid methane, probably mixed with other substances like liquid ethane, all of which are gases here on Earth. If there is life in Titan’s seas, it is not life as we know it. It must be an alien form of life, with organic molecules dissolved in liquid methane instead of liquid water. Is such a thing even possible?

The Cornell team took up one key part of this challenging question by investigating whether cell membranes can exist in liquid methane. Every living cell is, essentially, a self-sustaining network of chemical reactions, contained within bounding membranes. Scientists think that cell membranes emerged very early in the history of life on Earth, and their formation might even have been the first step in the origin of life.

Here on Earth, cell membranes are as familiar as high school biology class. They are made of large molecules called phospholipids. Each phospholipid molecule has a ‘head’ and a ‘tail’. The head contains a phosphate group, with a phosphorus atom linked to several oxygen atoms. The tail consists of one or more strings of carbon atoms, typically 15 to 20 atoms long, with hydrogen atoms linked on each side. The head, due to the negative charge of its phosphate group, has an unequal distribution of electrical charge, and we say that it is polar. The tail, on the other hand, is electrically neutral.

phospholipid membrane
Here on Earth, cell membranes are composed of phospholipid molecules dissolved in liquid water. A phospholipid has a backbone of carbon atoms (gray), and also contains hydrogen (sky blue), phosphorus (yellow), oxygen (red), and nitrogen (blue). Due to the positive charge associated with the nitrogen containing choline group, and the negative charge associated with the phosphate group, the head is polar, and attracts water. It is therefore hydrophilic. The hydrocarbon tail is electrically neutral and hydrophobic. The structure of a cell membrane is due these electrical properties of phospholipids and water. The molecules form a double layer, with the hydrophilic heads facing outward, towards water, and the hydrophobic tails facing inward, towards one another. Credit: Ties van Brussel

These electrical properties determine how phospholipid molecules will behave when they are dissolved in water. Electrically speaking, water is a polar molecule. The electrons in the water molecule are more strongly attracted to its oxygen atom than to its two hydrogen atoms. So, the side of the molecule where the two hydrogen atoms are has a slight positive charge, and the oxygen side has a small negative charge. These polar properties of water cause it to attract the polar head of the phospholipid molecule, which is said to be hydrophilic, and repel its nonpolar tail, which is said to be hydrophobic.

When phospholipid molecules are dissolved in water, the electrical properties of the two substances work together to cause the phospholipid molecules to organize themselves into a membrane. The membrane closes onto itself into a little sphere called a liposome. The phospholipid molecules form a bilayer two molecules thick. The polar hydrophilic heads face outward towards the water on both the inner and outer surface of the membrane. The hydrophobic tails are sandwiched between, facing each other. While the phospholipid molecules remain fixed in their layer, with their heads facing out and their tails facing in, they can still move around with respect to each other, giving the membrane the fluid flexibility needed for life.

Phospholipid bilayer membranes are the basis of all terrestrial cell membranes. Even on its own, a liposome can grow, reproduce and aid certain chemical reactions important to life, which is why some biochemists think that the formation of liposomes might have been the first step towards life. At any rate, the formation of cell membranes must surely been an early step in life’s emergence on Earth.

water and methane
At the left, water, consisting of hydrogen (H) and oxygen (O), is a polar solvent. Oxygen attracts electrons more strongly than hydrogen does, giving the hydrogen side of the molecule a net positive charge and the oxygen side a net negative charge. The delta symbol ( ) indicates that the charge is partial, that is less than a full unit of positive or negative charge. At right, methane is a non-polar solvent, due to the symmetrical distribution of hydrogen atoms (H) around a central carbon atom (C). Credit: Jynto as modified by Paul Patton.

If some form of life exists on Titan, whether sea monster or (more likely) microbe, it would almost certainly need to have a cell membrane, just like every living thing on Earth does. Could phospholipid bilayer membranes form in liquid methane on Titan? The answer is no. Unlike water, the methane molecule has an even distribution of electrical charges. It lacks water’s polar qualities, and so couldn’t attract the polar heads of phospholipid molecule. This attraction is needed for the phospholipids to form an Earth-style cell membrane.

Experiments have been conducted where phospholipids are dissolved in non-polar liquids at Earthly room temperature. Under these conditions, the phospholipids form an ‘inside-out’ two layer membrane. The polar heads of the phospholipid molecules are at the center, attracted to one another by their electrical charges. The non-polar tails face outward on each side of the inside-out membrane, facing the non-polar solvent.

membranes in polar and non-polar solvents
At left, phospholipids are dissolved in water, a polar solvent. They form a bilayer membrane, with their polar, hydrophilic heads facing outward towards water, and their hydrophobic tails facing each other. At right, when phospholipids are dissolved in a non-polar solvent at Earthly room temperature, they form an inside-out membrane, with the polar heads attracting one another, and the non-polar tails facing outwards towards the non-polar solvent. Based on figure 2 from Stevenson, Lunine, and Clancy (2015). Credit: Paul Patton

Could Titanian life have an inside out phospholipid membrane? The Cornell team concluded that this wouldn’t work, for two reasons. The first is that at the cryogenic temperatures of liquid methane, the tails of phospholipids become rigid, depriving any inside-out membrane that might form of the fluid flexibility needed for life. The second is that two key ingredients of phospholipids; phosphorus and oxygen, are probably unavailable in the methane lakes of Titan. In their search for Titanian cell membranes, the Cornell team needed to probe beyond the familiar realm of high school biology.

Although not composed of phospholipids, the scientists reasoned that any Titanian cell membrane would nevertheless be like the inside-out phospholipid membranes created in the lab. It would consist of polar molecules clinging together electrically in a solution of non-polar liquid methane. What molecules might those be? For answers the researchers looked to data from the Cassini spacecraft and from laboratory experiments that reproduced the chemistry of Titan’s atmosphere.

Titan’s atmosphere is known to have a very complex chemistry. It is made mostly of nitrogen and methane gas. When the Cassini spacecraft analyzed its composition using spectroscopy it found traces of a variety of compounds of carbon, nitrogen, and hydrogen, called nitriles and amines. Researchers have simulated the chemistry of Titan’s atmosphere in the lab by exposing mixtures of nitrogen and methane to sources of energy simulating sunlight on Titan. A stew of organic molecules called ‘tholins’ is formed. It consists of compounds of hydrogen and carbon, called hydrocarbons, as well as nitriles and amines.

The Cornell investigators saw nitriles and amines as potential candidates for their Titanian cell membranes. Both are polar molecules that might stick together to form a membrane in non-polar liquid methane due to the polarity of nitrogen containing groups found in both of them. They reasoned that candidate molecules must be much smaller than phospholipids, so that they could form fluid membranes at liquid methane temperatures. They considered nitriles and amines containing strings of between three and six carbon atoms. Nitrogen containing groups are called ‘azoto’ –groups, so the team named their hypothetical Titanian counterpart to the liposome the ‘azotosome’.

Synthesizing azotosomes for experimental study would have been difficult and expensive, because the experiments would need to be conducted at the cryogenic temperatures of liquid methane. But since the candidate molecules have been studied extensively for other reasons, the Cornell researchers felt justified in turning to the tools of computational chemistry to determine whether their candidate molecules could cohere as a flexible membrane in liquid methane. Computational models have been used successfully to study conventional phospholipid cell membranes.

acrylonitrile
Acrylonitrile has been identified as a possible basis for cell membranes in liquid methane on Titan. It is known to be present in Titan’s atmosphere at a concentration of 10 parts per million and has been produced in laboratory simulations of the effects of energy sources on Titan’s nitrogen-methane atmosphere. As a small polar molecule capable of dissolving in liquid methane, it is a candidate substance for the formation of cell membranes in an alternative biochemistry on Titan. Light blue: carbon atoms, dark blue: nitrogen atom, white: hydrogen atoms. Credit: Ben Mills as modified by Paul Patton.

acrylonitrile membrane
Polar acrylonitrile molecules align ‘head’ to ‘tail’ to form a membrane in non-polar liquid methane. Light blue: carbon atoms, dark blue: nitrogen atoms, white: hydrogen atoms. Credit: James Stevenson.

The group’s computational simulations showed that some candidate substances could be ruled out because they would not cohere as a membrane, would be too rigid, or would form a solid. Nevertheless, the simulations also showed that a number of substances would form membranes with suitable properties. One suitable substance is acrylonitrile, which Cassini showed is present in Titan’s atmosphere at 10 parts per million concentration. Despite the huge difference in temperature between cryogenic azotozomes and room temperature liposomes, the simulations showed them to exhibit strikingly similar properties of stability and response to mechanical stress. Cell membranes, then, are possible for life in liquid methane.

azotosome
Computational chemistry simulations show that acrylonitrile and some other small polar nitrogen containing organic molecules are capable of forming ‘azotosomes’ when they are dissolved on liquid methane. Azotosomes are small membrane bounded spherules like the liposomes formed by phospholipids when they are dissolved in water. The simulations show that acrylonitrile azotosomes would be both stable and flexible in cryogenically cold liquid methane, giving them the properties they need to function as cell membranes for hypothetical Titanian life, or for life on any world with liquid methane on its surface. The azotosome shown is 9 nanometers in size, about the size of a virus. Light blue: carbon atoms, dark blue: nitrogen atoms, white: hydrogen atoms. Credit: James Stevenson.

The scientists from Cornell view their findings as nothing more than a first step towards showing that life in liquid methane is possible, and towards developing the methods that future spacecraft will need to search for it on Titan. If life is possible in liquid methane, the implications ultimately extend far beyond Titan.

When seeking conditions suitable for life in the galaxy, astronomers typically search for exoplanets within a star’s habitable zone, defined as the narrow range of distances over which a planet with an Earth-like atmosphere would have a surface temperature suitable for liquid water. If methane life is possible, then stars would also have a methane habitable zone, a region where methane could exist as a liquid on a planet or moon, making methane life possible. The number of habitable worlds in the galaxy would be greatly increased. Perhaps, on some worlds, methane life evolves into complex forms that we can scarcely imagine. Maybe some of them are even a bit like sea monsters.

References and Further Reading:

N. Atkinson (2010) Alien Life on Titan? Hang on Just a Minute, Universe Today.

N. Atkinson (2010) Life on Titan Could be Smelly and Explosive, Universe Today.

M. L. Cable, S. M. Horst, R. Hodyss, P. M. Beauchamp, M. A. Smith, P. A. Willis, (2012) Titan tholins: Simulating Titan organic chemistry in the Cassini-Huygens era, Chemical Reviews, 112:1882-1909.

E. Howell (2014) Titan’s Majestic Mirror-Like Lakes Will Come Under Cassini’s Scrutiny This Week, Universe Today.

J. Major (2013) Titan’s North Pole is Loaded With Lakes, Universe Today.

C. P. McKay, H. D. Smith, (2005) Possibilities for methanogenic life in liquid methane on the surface of Titan, Icarus 178: 274-276.

J. Stevenson, J. Lunine, P. Clancy, (2015) Membrane alternatives in worlds without oxygen: Creation of an azotosome, Science Advances 1(1):e1400067.

S. Oleson (2014) Titan submarine: Exploring the depths of Kraken, NASA Glenn Research Center, Press release.

Cassini Solstice Mission, NASA Jet Propulsion Laboratory

NASA and ESA celebrate 10 years since Titan landing, NASA 2015

Oldest Planetary System Discovered, Improving the Chances for Intelligent Life Everywhere

Using data from the Kepler space telescope, an international group of astronomers has discovered the oldest known planetary system in the galaxy – an 11 billion-year-old system of five rocky planets that are all smaller than Earth. The team says this discovery suggests that Earth-size planets have formed throughout most of the Universe’s 13.8-billion-year history, increasing the possibility for the existence of ancient life – and potentially advanced intelligent life — in our galaxy.

“The fact that rocky planets were already forming in the galaxy 11 billion years ago suggests that habitable Earth-like planets have probably been around for a very long time, much longer than the age of our Solar System,” said Dr. Travis Metcalfe, Senior Research Scientist Space Science Institute, who was part of the team that used the unique method of asteroseismology to determine the age of the star.

The star, named Kepler-444, is about 25 percent smaller than our Sun and is 117 light-years from Earth. The system of five known planets is very compact, and all five planets orbit the parent star in less than 10 days, or within 0:08 AU, roughly one-fifth the size of Mercury’s orbit.

“The star is slightly cooler than the Sun (around 5000 K at the surface, compared to 5800 K),” Metcalfe told Universe Today, “but the planets in this system are still expected to be highly irradiated and inhospitable to life,” with little to no atmospheres.

The team wrote in their paper that the system’s habitable zone lies 0:47 AU from the parent star and so all planets orbit well interior to the inner edge of Kepler-444’s ‘Goldilocks zone.’

The team was led by Tiago Campante, a research fellow at the University of Birmingham in the UK.

The planets were found by analyzing four years of Kepler data, as the spacecraft had nearly continuous observations of Kepler-444 during Kepler’s active mission. The space telescope took high-precision measurements of changes in brightness in stars in its field of view. There are tiny changes in brightness when planets pass in front of their stars.

Transit signals indicated five planets orbiting Kepler-444, although this star has a binary companion, an M-dwarf, and it was a tedious process to tease out all the data to determine what were planets and not other stars, as well as which star the planets were orbiting.

An image of the Kepler-444 star system using the NIRC2 near-infrared imager on the Keck II telescope. Credit: Tiago Campante et al.
An image of the Kepler-444 star system using the NIRC2 near-infrared imager on the Keck II telescope. Credit: Tiago Campante et al.

Metcalfe said the the job of “validating” the planets by ruling out all of the other possible “false positive” scenarios is always a big challenge for Kepler targets.

But asteroseismology was used to directly measure the precise age of the star. Asteroseismology, or stellar seismology is basically listening to a star by measuring sound waves. The sound waves travel into the star and bring information back up to the surface. The waves cause oscillations that Kepler observes as a rapid flickering of the star’s brightness.

How can this help determine a star’s age?

“As a star ages, it converts hydrogen into helium in the core,” Metcalfe said via email. “This changes the mean density of the star over time, and asteroseismology provides a very precise measure of the mean density (from the regular spacing of the individual oscillation frequencies).”

Metcalfe said that in this case, the uncertainty on the age of the star (and thus the planets, which formed essentially at the same time) is only 9%, compared to a typical uncertainty of 30-50% from other methods based on rotation (gyrochronology) or other properties of the star.

The team also noted in their paper that this finding may also help to pinpoint the beginning of the era of planet formation.

“I think this system has a lot to teach us about planet formation and the long-term evolution of planetary systems,” said Darin Ragozzine, a professor at Florida Institute of Technology and a a member of the discovery team, who specializes in multi-transiting systems. “With an age of 11.2 billion years, it means that this system formed near the beginning of the age of the Universe.”

The team wrote that this finding implies that small, Earth-size, planets may have readily formed at early epochs in the Universe’s history, even when metals were more scarce.

“By the time Earth formed, this star and its planetary system were already older than our planet is today,” Ragozzine told Universe Today. “We don’t know for sure if this system has stayed the same the whole time, but it is amazing to think that the little inner planet has gone around the star about a trillion times!”

To find out more about asteroseismology, check out a website called the Pale Blue Dot Project. Metcalfe launched a non-profit organization to help raise research funds for the Kepler Asteroseismic Science Consortium. The Pale Blue Dot Project allows people to adopt a star to support asteroseismology, since there is no NASA funding for asteroseismology.

“Much of the expertise for this exists in Europe and not in the US, so as a cost saving measure NASA outsourced this particular research for the Kepler mission,” said Metcalfe, “and NASA can’t fund researchers in other countries.”

Metcalfe added that the “adopt a star” program supported the asteroseismic analysis of Kepler-444, “determining the precise age that makes this ancient planetary system so interesting… This private funding from citizens around the world has been an invaluable resource to facilitate our research and fuel amazing discoveries like this one.”

You can help this research by adopting one of the Kepler stars or planetary systems.

This research was published today in the Astrophysical Journal.

The team’s paper is titled, “An Ancient Extrasolar System with Five Sub-Earth-Size Planets.”

Europa Life: Could ‘Extreme Shrimp’ Point To Microbes On That Moon?

For all of the talk about aliens that we see in science fiction, the reality is in our Solar System, any extraterrestrial life is likely to be microbial. The lucky thing for us is there are an abundance of places that we can search for them — not least Europa, an icy moon of Jupiter believed to harbor a global ocean and that NASA wants to visit fairly soon. What lurks in those waters?

To gain a better understanding of the extremes of life, scientists regularly look at bacteria and other lifeforms here on Earth that can make their living in hazardous spots. One recent line of research involves shrimp that live in almost the same area as bacteria that survive in vents of up to 750 degrees Fahrenheit (400 degrees Celsius) — way beyond the boiling point, but still hospitable to life.

Far from sunlight, the bacteria receive their energy from chemical combinations (specifically, hydrogen sulfide). While the shrimp certainly don’t live in these hostile areas, they perch just at the edge — about an inch away. The shrimp feed on the bacteria, which in turn feed on the hydrogen sulfide (which is toxic to larger organisms if there is enough of it.) Oh, and by the way, some of the shrimps are likely cannibals!

One species called Rimicaris hybisae, according to the evidence, likely feeds on each other. This happens in areas where the bacteria are not as abundant and the organisms need to find some food to survive. To be sure, nobody saw the shrimps munching on each other, but scientists did find small crustaceans inside them — and there are few other types of crustaceans in the area.

But how likely, really, are these organisms on Europa? Bacteria might be plausible, but something larger and more complicated? The researchers say this all depends on how much energy the ecosystems have to offer. And in order to see up close, we’d have to get underwater somehow and do some exploring.

In a recent Universe Today interview with Mike Brown, a professor of planetary science at the California Institute of Technology, the renowned dwarf-planet hunter talked about how a submarine could do some neat work.

“In the proposed missions that I’ve heard, and in the only one that seems semi-viable, you land on the surface with basically a big nuclear pile, and you melt your way down through the ice and eventually you get down into the water,” he said. “Then you set your robotic submarine free and it goes around and swims with the big Europa whales.” You can see the rest of that interview here.

Source: Jet Propulsion Laboratory

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute
The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute

How Do Aliens Think? We Need To Learn About Their Biology First, Analyst Argues

TORONTO, CANADA – Should E.T. finally give Earth a ring, it’s not only important to understand what the message says but why it is being sent, a speaker at a talk about extraterrestrials urged this week. This requires understanding about alien social behavior, also known as sociology.

“We keep complaining about the fact that we know so little about extraterrestrials in general, and even though sociology is mentioned in the Drake Equation, it is generally agreed that is the most difficult aspect to address,” said Morris Jones, an Australian who describes himself as an independent space analyst.

The Drake Equation is a set of variables proposed by astronomer Frank Drake that estimates how many intelligent, communicating civilizations there are in the universe. While speaking at the International Astronautical Congress Wednesday (Oct. 1), Jones pointed out that most talk about alien communications focuses on the basics – how they transmit, and where to search, and whether we can hear them. But to fully understand the message, we have to understand how their society works.

Extraterrestrials in the 1979 movie "Close Encounters of the Third King." Credit: Columbia Pictures / Alien Wiki
Extraterrestrials in the 1979 movie “Close Encounters of the Third Kind.” Credit: Columbia Pictures / Alien Wiki

How a society functions is partly a function of biology, Jones argued. So if humans decided to incorporate machine intelligence in their bodies, it would be reasonable to assume that society would change because of that. “Machine society is an entirely different sociology, and that we cannot predict,” Jones said. An extraterrestrial civilization could use machines, drugs, genetic engineering or surgery to alter their basic nature (something that is used also with humans.)

Class systems could also be in place that are similar to the animal kingdom. Herd and hive sociology covers how animals behave. Pigeons, for example, flock together for mutual protection. In the insect world, beings such as ants tend to be born in specific physiological roles that prepare them for different functions — such as the queen ant that is the mother of other ants in the colony.

These are societies that we could predict, perhaps, but more intriguing are those that are difficult to extrapolate from human experience or observation. Jones is particularly interested in cryptosociology. That’s the concept that because we can’t predict yet how alien civilizations will behave, we can speculate what they are capable of.

SETI's Allen Telescope Array monitor the stars for signs of intelligent life (SETI.org)
SETI’s Allen Telescope Array monitors the stars for signs of intelligent life (SETI.org)

Here’s where the danger lies, Jones said: it’s possible to make unfounded assumptions that cannot be tested through science. “If our thinking is too wild it could degenerate into dragons and unicorns, and become a pseduo science. At some point it has to be a framework of … reason and evidence,” he said.

Here, Jones urges using systems theories that would make each system consistent with itself. On Earth, if a system contradicts itself it disappears — such as with ancient civilizations that failed.

While he didn’t detail what these systems could be — predicting them would be difficult, he said — Jones argued it would be tough to really know the true sociology of extraterrestrial civilizations when we not only are ignorant about their biology, but aspects of our own sociology.

Companion Planet Could Keep Alien Earths Warm In Old Age: Study

People are generally social creatures, and in the case of planets that generally is the case as well. Many of these alien worlds we have discovered are in groups of two or more around their parent star or stars. A new study, however, goes a step further and says that a companion planet could actually save another planet in its old age.

“Planets cool as they age. Over time their molten cores solidify and inner heat-generating activity dwindles, becoming less able to keep the world habitable by regulating carbon dioxide to prevent runaway heating or cooling,” the University of Washington stated.

“But astronomers … have found that for certain planets about the size of our own, the gravitational pull of an outer companion planet could generate enough heat — through a process called tidal heating — to effectively prevent that internal cooling, and extend the inner world’s chance at hosting life.”

The researchers ran computer models finding that tidal heating, which is known to happen on Jupiter’s moons Europa and Io, can also happen in planets the size of Earth that are in non-circular orbits around dwarf stars. An outer planet would keep the orbit from stabilizing in a circle, generating tidal heating and keeping conditions potentially warm enough for life.

The study, led by the University of Arizona’s Christa Van Laerhoven, will be available in the Monthly Notices of the Royal Astronomical Society and is available now in preprint version on Arxiv.