Life Beyond Earth: Is interstellar space travel to TRAPPIST-1 possible?

Thomas Carlon

In humans’ search for extraterrestrial life, we often find ourselves wondering if human life could exist elsewhere in the universe. Over the years, nearly 3,500 planets have been discovered orbiting stars in the universe, however, none have been quite as publicized as the TRAPPIST-1 solar system.[1] The discovery of TRAPPIST-1 could ignite new approaches to researching planets outside of our solar system, and potential interstellar travel.

The TRAPPIST-1 solar system is almost identical to that of our own solar system, it has eight orbiting planets, three of which could sustain human life. The orbiting planets of TRAPPIST-1 have radii between three-quarters and one times that of Earth, with masses ranging from 50%-150% of Earth’s mass.[2] Moreover, because all the planets are smaller than 1.6 times that of Earth’s radius, the planets of TRAPPIST-1 are more likely to be rocky worlds, as opposed to gaseous planets such as our very own Neptune. Furthermore, the possibility of sustaining human life is exponentially increased, because three of the planets d, e, and f are within the temperate region of the sun.[3] Thus, the possibility of liquid water existing on the surface is high.[4]

While our search continues for habitable planets like Earth. The search always focuses on the potential for the presence of water, typically ice worlds that have melted are preferable. For example, Earth’s surface is comprised of 71% water, however, water only makes up 0.1% of the planet’s mass.[5] Moreover, because Earth’s seafloor is separated mostly by water from the atmosphere, this allows for a carbon-silicate cycle to form – which essentially acts as a thermostat to adjust the carbon dioxide warmth in Earth’s atmosphere.[6]  However, this could prove troublesome for the temperate planets of TRAPPIST-1. The planets of TRAPPIST-1 are situated so close to their star that the planets are potentially in “tidal lock.” Where the face of the planet is permanently turned towards the star, where one face is in a state of constant day, and the other face in night. Moreover, the associated weather patterns could evaporate all water and eliminate the atmosphere if the winds of the planets are unable to redistribute the heat. Finally, the planets are seemingly in circular orbits – which could trigger a second form of heating called “tidal heating.”[7] Essentially, a small ellipticity in a planet would cause the star’s gravity to strengthen and weaken during the year, flexing the planet like a Bug Out Bob, generating vast amounts of heat.

Given all this information, it is still possible that life may be habitable on the temperate planets of the TRAPPIST-1 solar system. The key factors being that the planets contain water, that the surface is not entirely covered by water, it contains a carbon-silicate cycle, and that the planets remain in their seemingly circular orbitals patterns. However, reaching the solar system may prove to be the largest hurdle to overcome.

TRAPPIST-1 sits, patiently awaiting it’s arrival of human life, 39 light-years away from Earth. Placed in a more contextual quantity, 229 trillion miles (369 trillion kilometers) away from Earth.[8] To put this distance in perspective, New Horizons, the fastest spacecraft ever launched from Earth, flew past Pluto in 2015 around 32,000 miles per hour (“mph”).[9] Which would take New Horizons around 817,000 years to reach TRAPPIST-1.[10] Furthermore, NASA’s space shuttle travels around the Earth around 17,500 mph, and would take 1.5 million years to reach TRAPPIST-1.[11] Essentially, it is impossible for humans to travel to the TRAPPIST-1 solar system anytime soon. Even if Stephen Hawking’s theoretical Starshot’s interstellar probes[12] were used to launch humans to TRAPPIST-1 it would still take less than 200 years – which would mean your ancestors would witness the arrival to TRAPPIST-1, not you.

With today’s technology, the feasibility of reaching TRAPPIST-1 to further explore the habitability of that solar system is zero. Humans might one day see the potential to travel vast distances across the universe, like in Interstellar. However, humans should stick closer to home for space exploration – the colonization of Mars sounds like a better start.

 

 

[1] Elizabeth Tasker, It’s our Solar System in miniature, but could TRAPPIST-1 host another Earth?, The Conversation, February 24, 2017 2:40am, https://theconversation.com/its-our-solar-system-in-miniature-but-could-trappist-1-host-another-earth-73482.

[2] Id.

[3] Id.

[4] Id.

[5] Id.

[6] Elizabeth Tasker, It’s our Solar System in miniature, but could TRAPPIST-1 host another Earth?, The Conversation, February 24, 2017 2:40am, https://theconversation.com/its-our-solar-system-in-miniature-but-could-trappist-1-host-another-earth-73482.

[7] Id.

[8] Hanneke Weltering, TRAPPIST-1: How Long Would It Take to Fly to 7-Planet System? LiveScience, February 23, 2017 (2:47pm ET), http://www.livescience.com/57993-trappist-1-alien-planets-travel-time.html.

[9] Id.

[10] Id.

[11] Id.

[12] Karl Tate, How Breakthrough Starshot’s Interstellar Probes Would Work (Infographic), Space.com, April 12, 2016 (6:07pm ET), http://www.space.com/32551-breakthrough-starshot-interstellar-spacecraft-infographic.html.