The seven planets and the ultracool dwarf: Why life in the Trappist-1 system could be decidedly weird

NASA has announced the discovery of a seven-planet system orbiting an ultracool red dwarf; one of the best hopes for finding life beyond Earth yet. But if Trappist-1 does host life, it will be like nothing we've ever encountered before

Yesterday NASA announced the discovery of seven Earth-sized exoplanets orbiting a small, dim star 40 light years from Earth. Trappist-1 is an unprecedented discovery, and is sure to keep astronomers busy for decades to come, but also offers one of our best hopes in the hunt for extra-terrestrial life.

Located in the Aquarius constellation, the exoplanet system contains three planets in the habitable zone, of which at least two are thought to have a rocky surface. And while this doesn’t guarantee the existence of life in the system, it does make it worthy of further investigation.

“Three of these planets are in the habitable zone where liquid water can pool on the surface. In fact, with the right atmospheric conditions there could be water on any of these planets,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington.

Over the next decade scientists will be performing numerous follow-up studies, with the soon-to-be-launched James Webb Space Telescope enabling scientists to detect evidence of water, methane, oxygen and other vital building blocks of life when it comes online in 2018.

“These planets are among the best of all the planets we know to follow up, to see the atmospheres, and also to look at biosignatures – if there are any,” added Zurbuchen.

“The discovery gives us a hint that finding a second Earth is not just a matter of if, but when.”

Under different suns

Trappist-1’s star is quite different ­­from our own Sun, meaning that any life that has evolved in its presence would be quite unlike that of Earth.

Most significantly, Trappist-1 is a red dwarf star, a class of stars also known as M-dwarfs that are increasingly being targeted in the search for life.

This M-dwarf is considerably smaller and burns at a lower temperature than our solar system’s star, and is smaller and cooler than most other M-dwarfs, hence the ultracool classification.  As a result, liquid water can exist on planets orbiting very close to it; the seven planets hug their star in tight orbits, all of which are closer than our innermost planet Mercury’s orbit of the sun.

This also means that the planets orbit considerably closer to each other than we do with our own planetary neighbours. If you were standing on the surface of one of the Trappist-1 planets, your planetary neighbour on some days would hang larger than our own Moon in the sky, and might be close enough to see its mountain ranges or cloud cover.

The sun would also be a far greater presence in the sky, looming six times larger than our own.

This would also mean trips between different planets in the system could take just a couple of days, potentially allowing if not life in the system then future humans to hop across Trappist-1.

A year a week

Because the planets are so much closer to their sun, their years are very different to our own, ranging from 1.5 days for the closest planet to the star to 20 days for the farthest.

For the three planets in the habitable zone, snappily named Trappist-1e, f and g, years are 6.1 days, 9.2 days and 12.4 days long respectively.

What impact, if any, that could have on life is unclear, but it does have the potential to affect how life evolves; on Earth many forms of life have seasonal responses that are influenced by the changes and length of our year.

Forever day, eternal night

NASA also believes that the planets may be tidally locked, meaning that one side of each is always facing the sun. This would result in life on the planets either eternally basking in daylight, or permanently shrouded in darkness.

Images courtesy of NASA-JPL/Caltech

It would also make for a very different weather system on each planet, with extreme temperature changes, and strong winds over the terminator – the line between day and night.

This could mean that life would require a certain atmosphere to be present for it to survive, in order to transport heat and moderate the overall climate, which is something that astronomers will know more about once the James Webb space telescope launches in 2018.

However, the wavelength of light Trappist-1’s star is supplying is also different to our own sun. This will result in a different hue, with a duskier red-orange daylight.

This would affect the wavelengths of light that life would be exposed to, and so would have an impact on how biological systems evolved in response. On Earth, plants photosynthesise best at specific wavelengths and have evolved to reflect unwanted green light from the Sun, giving them their colour. But on the Trappist-1 planets there will be a different spectrum of light, requiring any plants to adapt differently to their environment.

As a result, plants on Trappist-1’s planets could have orange and black foliage rather than our own green.

The hunt is on

Now that the world knows about the existence of the planets, scientists are scrambling to learn more about them. However, with no ability to send anything directly, there are limitations on what we can currently learn, and the scientists are keen to stress that any life found is highly unlikely to be sentient.

“I’m just talking about slime here – it’s far easier to evolve than sentient beings.” said Victoria Meadows of the University of Washington, the principal investigator for the NASA Astrobiology Institute’s Virtual Planetary Laboratory. “The majority of life we find out there is likely to be single cell, relatively primitive life.”

However, when the James Webb Space Telescope (JWST) finally comes online next year, scientists will be able to start looking for an atmosphere.

The majority of life we find out there is likely to be single cell, relatively primitive life.

“We will look at the atmosphere for gases that do not belong – gases  that might be attributed to life,” said Sara Seager, a professor of planetary science and physics at MIT, in a Reddit AMA. “We will not know if the gases are produced by microbial life or by intelligent alien species.”

Beyond that, we will need to build more sophisticated equipment if we are to determine what the flora and fauna of Trappist-1 is really like.

“In order to see vegetation and any other surface features (e.g. oceans, continents), we’ll need future telescopes beyond JWST that will be able to directly image exoplanets,” added Giada Arney, an astrobiologist at NASA Goddard Space Flight Center.

“We’ll need farther future technology that may become available in the coming decades that will allow us to block out the star’s light and observe the planets directly.”

Adding stem cells to the brains of mice “slowed or reversed” ageing

Albert Einstein College of Medicine scientists “slowed or reversed” ageing in mice by injecting stem cells into their brains.

The study, published online in the journal Nature, saw the scientists implant stem cells into mice’s hypothalamus, which caused molecules called microRNAs (miRNAs) to be released.

The miRNA molecules were then extracted from the hypothalamic stem cells and injected into the cerebrospinal fluid of two groups of mice: middle-aged mice whose hypothalamic stem cells had been destroyed and normal middle-aged mice.

This treatment significantly slowed aging in both groups of animals as measured by tissue analysis and behavioural testing that involved assessing changes in the animals’ muscle endurance, coordination, social behaviour and cognitive ability.

“Our research shows that the number of hypothalamic neural stem cells naturally declines over the life of the animal, and this decline accelerates aging,” said senior author Dongsheng Cai, M.D., Ph.D., professor of molecular pharmacology at Einstein.

“But we also found that the effects of this loss are not irreversible. By replenishing these stem cells or the molecules they produce, it’s possible to slow and even reverse various aspects of aging throughout the body.”

To reach the conclusion that stem cells in the hypothalamus held the key to aging, the scientists first looked at the fate cells in the hypothalamus as healthy mice got older.

The number of hypothalamic stem cells began to diminish when the mice reached about 10 months, which is several months before the usual signs of aging start appearing. “By old age—about two years of age in mice—most of those cells were gone,” said Dr. Cai.

Images courtesy of the Mayo Clinic.

The researchers next wanted to learn whether this progressive loss of stem cells was actually causing aging and was not just associated with it.

To do this, the scientists observed what happened when they selectively disrupted the hypothalamic stem cells in middle-aged mice.

“This disruption greatly accelerated aging compared with control mice, and those animals with disrupted stem cells died earlier than normal,” said Dr. Cai.

Finally, to work out whther adding stem cells to the hypothalamus counteracted ageing, the scientists injected hypothalamic stem cells into the brains of middle-aged mice whose stem cells had been destroyed as well as into the brains of normal old mice.

In both groups of animals, the treatment slowed or reversed various measures of aging.

The scientists are now trying to identify the particular populations of microRNAs that are responsible for the anti-aging effects seen in mice, which is perhaps the first step toward slowing the aging process and successfully treating age-related diseases in humans.

Self-driving delivery cars coming to UK roads by 2018

A driverless vehicle designed to deliver goods to UK homes is set to take to the road next year after the successful conclusion of an equity crowdfunding campaign.

Developed by engineers at The University of Aberystwyth-based startup The Academy of Robotics, the vehicle, Kar-Go, is road-legal, and capable of driving on roads without any specific markings without human intervention.

Kar-Go has successfully raised £321,000 through Crowdcube – 107% of its goal – meaning the company now has the funds to build its first commercially ready vehicles. This amount will also, according to William Sachiti, Academy of Robotics founder and CEO, be matched by “one of the largest tech companies” in the world.

Images courtesy of Academy of Robotics

The Academy of Robotics has already built and tested a prototype version of Kar-Go, and is working with UK car manufacturer Pilgrim to produce the fully street-legal version.

The duo has already gained legal approval from the UK government’s Centre for Autonomous Vehicles, meaning the cars will be able to immediately operate on UK roads once built.

The aim of Kar-Go is to partner with suppliers of everyday consumer goods to significantly reduce the cost of deliveries, and the company’s goal in this area is ambitious: Sachiti believes Kar-Go could reduce delivery costs by as much as 98%.

Whether companies go for the offering remains to be seen, but the company says it is in early stage discussions with several of the largest fast-moving consumer goods companies in Europe, which would likely include the corporations behind some of the most recognisable brands found in UK supermarkets.

Introducing Kar-go Autonomous Delivery from Academy of Robotics on Vimeo.

While some will be sceptical, Sachiti is keen to drive the company to success, and already has an impressive track record in future-focused business development. He previously founded Clever Bins – the solar powered digital advertising bins found in many of the nation’s cities – and digital concierge service MyCityVenue – now part of SecretEscapes.

“As a CEO, it is one of my primary duties to make sure Kar-go remains a fantastic investment, this can only be achieved by our team producing spectacular results. We can’t wait to show the world what we produce,” he said.

“We have a stellar team who are excited to have begun working on what we believe will probably be the best autonomous delivery vehicle in the world. For instance, our multi-award winning lead vehicle designer is part of the World Championship winning Brabham Formula One design team, and also spent years as a Design Engineer at McLaren.”