Artist’s impression of the ultracool dwarf star TRAPPIST-1 from the surface of one of its planets
Eyes turn upward once again as the discovery of the Trappist-1 system renews people’s hopes for interplanetary travel. Not only is the system a mere 39 lightyears off (roughly 12 parsecs), it is comprised of seven planets which appear to be roughly equivalent to Earth, at least in terms of size, mass, and composition.
The presence of a whole new solar system is exciting for many reasons. Trappist-1A, the central star of the system, is an ultra-cool dwarf, which has earned it the nickname “Tyrion” in some circles. Being only a little larger than our own system’s Jupiter, the star holds its planets in a tight orbit, and were they relocated to our solar system, the furthest one, Trappist-1H, would be roughly equal to the asteroid belt.
The limited distance limits the orbital period as well. Earth’s orbital period lasts approximately 365 days, but the planets of the Trappist system have such quick orbits, even the longest ‘year’ is done before a month is out! Trappist-1H has an orbital period lasting roughly 20 days, and 1B, the closest planet, completes 13 ‘years’ in that same time (its period is 1.5 days long). “Given their short orbital distances, it is likely that the planets are tidally locked,” explained the scientists in their May 2016 article in Nature*. “Their rotations have been synchronized with their orbits.” Thus, just like the Moon does to Earth, one side of the planets perpetually faces the dwarf star. The constant exposure allows liquid water to exist on even the furthest planet.
Eliminating the need to provide water ourselves means plans to reach the Trappist system are further along than any other exploratory mission. While many organizations are beginning to comb through applicants to select those willing to make the trip, researchers continue to monitor the system using the Kepler satellite (K2). However, not everyone is necessarily thrilled at the concept of 7 new planets. Concerns are growing that planet discovery and colonization may become far more political than most scientists would hope, especially considering how few policies are currently in place to handle such scenarios. In 1979, the Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (commonly known as the Moon Treaty) established that the international community as a whole would be responsible for the jurisdiction of all celestial bodies. However, since its introduction, only 17 members of the United Nations have signed and ratified the treaty, and none of those that have are part of the ongoing space exploration projects. Because of this, there exists the very real possibility of the United States sending people to Trappist not only to discover, but also to defend. In addition, the closeness of the planets means it takes maybe two weeks to land on them all, inducing a race with even higher stakes than the one for the Moon.
The wonder of the planets ought to be shared amongst the entire population, especially considering how it was discovered by the collaboration of scientists worldwide. It is perhaps with these new resources we may be able to move towards a more unified front, or at least an increase in communications between all corners of the globe. After all, there may be something in the system which requires our collective attention.
* The 2016 Nature article was written and published by Michaël Gillon, Emmanuël Jehin, Susan M. Lederer, Laetitia Delrez, Julien de Wit, Artem Burdanov, Valérie Van Grootel, Adam J. Burgasser, Amaury H. M. J. Triaud, Cyrielle Opitom, Brice-Olivier Demory, Devendra K. Sahu, Daniella Bardalez Gagliuffi, Pierre Magain, and Didier Queloz.
