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.”

Soviet report detailing lunar rover Lunokhod-2 released for first time

Russian space agency Roskosmos has released an unprecedented scientific report into the lunar rover Lunokhod-2 for the first time, revealing previously unknown details about the rover and how it was controlled back on Earth.

The report, written entirely in Russian, was originally penned in 1973 following the Lunokhod-2 mission, which was embarked upon in January of the same year. It had remained accessible to only a handful of experts at the space agency prior to its release today, to mark the 45th anniversary of the mission.

Bearing the names of some 55 engineers and scientists, the report details the systems that were used to both remotely control the lunar rover from a base on Earth, and capture images and data about the Moon’s surface and Lunokhod-2’s place on it. This information, and in particularly the carefully documented issues and solutions that the report carries, went on to be used in many later unmanned missions to other parts of the solar system.

As a result, it provides a unique insight into this era of space exploration and the technical challenges that scientists faced, such as the low-frame television system that functioned as the ‘eyes’ of the Earth-based rover operators.

A NASA depiction of the Lunokhod mission. Above: an image of the rover, courtesy of NASA, overlaid onto a panorama of the Moon taken by Lunokhod-2, courtesy of Ruslan Kasmin.

One detail that main be of particular interest to space enthusiasts and experts is the operation of a unique system called Seismas, which was tested for the first time in the world during the mission.

Designed to determine the precise location of the rover at any given time, the system involved transmitting information over lasers from ground-based telescopes, which was received by a photodetector onboard the lunar rover. When the laser was detected, this triggered the emission of a radio signal back to the Earth, which provided the rover’s coordinates.

Other details, while technical, also give some insight into the culture of the mission, such as the careful work to eliminate issues in the long-range radio communication system. One issue, for example, was worked on with such thoroughness that it resulted in one of the devices using more resources than it was allocated, a problem that was outlined in the report.

The document also provides insight into on-Earth technological capabilities of the time. While it is mostly typed, certain mathematical symbols have had to be written in by hand, and the report also features a number of diagrams and graphs that have been painstakingly hand-drawn.

A hand-drawn graph from the report, showing temperature changes during one of the monitoring sessions during the mission

Lunokhod-2 was the second of two unmanned lunar rovers to be landed on the Moon by the Soviet Union within the Lunokhod programme, having been delivered via a soft landing by the unmanned Luna 21 spacecraft in January 1973.

In operation between January and June of that year, the robot covered a distance of 39km, meaning it still holds the lunar distance record to this day.

One of only four rovers to be deployed on the lunar surface, Lunokhod-2 was the last rover to visit the Moon until December 2013, when Chinese lunar rover Yutu made its maiden visit.

Robot takes first steps towards building artificial lifeforms

A robot equipped with sophisticated AI has successfully simulated the creation of artificial lifeforms, in a key first step towards the eventual goal of creating true artificial life.

The robot, which was developed by scientists at the University of Glasgow, was able to model the creation of artificial lifeforms using unstable oil-in-water droplets. These droplets effectively played the role of living cells, demonstrating the potential of future research to develop living cells based on building blocks that cannot be found in nature.

Significantly, the robot also successfully predicted their properties before they were created, even though this could not be achieved using conventional physical models.

The robot, which was designed by Glasgow University’s Regius Chair of Chemistry, Professor Lee Cronin, is driven by machine learning and the principles of evolution.

It has been developed to autonomously create oil-in-water droplets with a host of different chemical makeups and then use image recognition to assess their behaviour.

Using this information, the robot was able to engineer droplets to have different properties­. Those which were found to be desirable could then be recreated at any time, using a specific digital code.

“This work is exciting as it shows that we are able to use machine learning and a novel robotic platform to understand the system in ways that cannot be done using conventional laboratory methods, including the discovery of ‘swarm’ like group behaviour of the droplets, akin to flocking birds,” said Cronin.

“Achieving lifelike behaviours such as this are important in our mission to make new lifeforms, and these droplets may be considered ‘protocells’ – simplified models of living cells.”

One of the oil droplets created by the robot

The research, which is published today in the journal PNAS, is one of several research projects being undertaken by Cronin and his team within the field of artificial lifeforms.

While the overarching goal is moving towards the creation of lifeforms using new and unprecedented building blocks, the research may also have more immediate potential applications.

The team believes that their work could also have applications in several practical areas, including the development of new methods for drug delivery or even innovative materials with functional properties.