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.”

Former US presidential candidate Ralph Nader warns against over-hyping driverless cars

Former presidential candidate Ralph Nader has said that unsubstantiated claims from driverless car enthusiasts are distracting authorities from improving transport links and improving road and rail infrastructure.

In a blog post, Nader argues that the while the many advantages of a possible driverless future have been reported by the media, they have not been properly scrutinised, and the technology is draining much-needed funds that should be made available to mass transit services and the industry’s own vehicle safety upgrades.

“The mass media took the bait and over-reported each company’s sensationalised press releases, announcing breakthroughs without disclosing the underlying data,” said Nader.

“The arrogance of the algorithms, among many other variables, bypassed simple daily realties such as bustling traffic in cities like New York.”

Image courtesy of Don LaVange

Nader makes the claim that the predicted decline in car sales has led car companies to promote their high-ticket, driverless cars, which as Nader points out are already being marketed as “computers on wheels”.

However, Nader argues no explanation has been given for how autonomous vehicles would be implanted into normal people’s daily lives, and the problems of cars being hacked or requiring humans to take over haven’t been resolved.

“The industry, from Silicon Valley to Detroit, argues safety. Robotic systems do not get drunk, fall asleep at the wheel or develop poor driving skills. But computers fail often; they are often susceptible to hacking, whether by the manufacturers, dealers or deadly actors,” said Nader.

“Already, Level Three—an autonomous vehicle needing emergency replacement by the surrogate human driver—is being viewed as unworkable by specialists at MIT and elsewhere. The human driver, lulled and preoccupied, can’t take back control in time.”

Nader also makes the point in his blog post that driverless cars are diverting funding away from making cars we already have safer, more efficient and less polluting.

It is Nader’s opinion that we shouldn’t wait for what he terms a “technological will-o’-the-wisp”, and we should instead make changes to the cars we already have, as well as improving public transportation and infrastructure.

“The driverless car is bursting forth without a legal, ethical and priorities framework. Already asking for public subsidies, companies can drain much-needed funds for available mass transit services and the industry’s own vehicle safety upgrades,” said Nader.

“Why won’t we concentrate on what can be improved and expanded to get safer, efficient, less polluting mobility?”

Self-driving shopping: Autonomous grocery delivery trialled in London

The first trials of a self-driving grocery delivery service have started in Greenwich, London, as part of a wider project looking into the use of autonomous vehicles for ‘last mile’ deliveries.

An initiative between UK government and industry funded smart mobility lab the GATEway project and Ocado Technology, a part of the world’s largest online-online supermarket, the trail uses a cargo-carrying self-driving vehicle known as CargoPod. Developed by Oxbotica, the vehicle can carry 128kg of groceries at a time, as is designed to drive in areas populated by pedestrians thanks to its software system Selenium.

“Last mile delivery is a growing challenge as our cities become denser and more congested,” said Graeme Smith, CEO of Oxbotica. “In this new project we are working closely with Ocado Technology to deploy our Selenium autonomy system into a novel last-mile delivery application in Greenwich as a part of the GATEway project.”

Running over ten days, the trail will see groceries delivered to over 100 residents across the Royal Riverside Arsenal development in the borough of Greenwich. The project is the latest in a series of trials of self-driving vehicles in the borough, which have been primarily focused on their operation in areas also used by pedestrians.

“The Royal Borough of Greenwich is one of the UK’s leaders in smart city innovation and we are proud to be working alongside our partners to be at the forefront in this new age of driverless technology,” Councillor Sizwe James, cabinet member for transport, economy and smart cities at the Royal Borough of Greenwich.

“With Digital Greenwich spearheading this work forwards, we are gaining new insights into how connected and autonomous vehicles, including automated light delivery vehicles, will impact on the city and what cities need to do to capture the opportunities they can bring.”

Images courtesy of the GATEway project

The eventual goal of the project is to bring self-driving vehicles into general use in the UK.

“The GATEway project takes us another step closer to seeing self-driving vehicles on UK roads, and has the potential to reduce congestion in urban areas while reducing emissions,” said UK Business Minister Claire Perry. “Backed by government, this project firmly establishes the UK as a global centre for developing self-driving innovation.”

As part of this, there has been a strong focus on the commercial opportunities of self-driving vehicles, as evidenced by the involvement of Ocado.

“Ocado Technology is delighted to have worked in partnership with the GATEway Project to a complete a very successful grocery delivery trial using driverless vehicles. We are always looking to come up with unique, innovative solutions to the real-world challenge of delivering groceries in densely-populated urban environments,” said David Sharp, Head of 10x Technology at Ocado.

“This project is part of the on-going journey to be at the edge of what is practical and offer our Ocado Smart Platform customers new and exciting solutions for last mile deliveries.”