When NASA announced in February the discovery of TRAPPIST-1, a planetary system comprising seven exoplanets, it said three were potentially habitable and all the seven planets are closely knit with a shorter distance between the planets.
This has led to researchers working on the topic whether life forms from one planet can seed life in other planets, especially in planetary systems where interplanetary distances are too short.
The study led by Sebastiaan Krijt, a postdoctoral scholar at the University of Chicago, along with other scientists analyzed whether life forms from one planet can inject life in other planets as well.
They argue that organisms of a planet are likely to take a hitch ride on space debris if an event like asteroid impact takes place, which will fling rocks and other stuff far and wide.
Material Exchange Between Adjacent Planets
"Frequent material exchange between adjacent planets in the tightly packed TRAPPIST-1 system appears likely," said Krijt, the lead author. He affirmed that any material containing life offers the likelihood of inoculating life in other planets as well.
The closeness of the planets in TRAPPIST-1 has been described by NASA.
"If a person were standing on one of the planet's surface, they could gaze up and see geological features or clouds of neighboring worlds, which would appear larger than the moon in Earth's sky."
NASA estimated that the TRAPPIST-1 exoplanets are at a distance of 40 light-years (235 trillion miles) from Earth yet closer to Earth and they are part of the Aquarius constellation.
The study has been published in Astrophysical Journal Letters.
Simulations for TRAPPIST-1 conducted by the researchers gave the indication that debris led material transfer to other planets could occur at a shorter period of 10 years.
Asteroid Hit Scenario And Transfer Of Material
In an asteroid impact scenario, large rocks and other material are flung into space and they will keep floating until the nearby planet's gravitational force takes over and start dragging them to the surface.
Such a journey can help bacteria and other unicellular organisms to take a hitch ride on the debris and enter other planets.
For TRAPPIST-1, the probability is too high. Compared to the average 100 years taken for transferring 10 percent of the material from one planet to another habitable planet, Trappist-1 planets will need just 10 years to conduct the transfer of material given their closeness.
"Transport between planets f and g stands out as being particularly fast and effective, with some material being transferred within 10 years of being released," the team said.
Fred Ciesla, the study's coauthor highlighted the study's significance in the context of tightly packed planetary systems being discovered too frequently.
Scientists are hopeful that planets in the TRAPPIST-1 system might be harboring life-supporting conditions.
Given that TRAPPIST-1 planets are showcased as most habitable exoplanets, NASA will intensify the focus on them with the upcoming James Webb Telescope to identify the atmospheres to draw definite conclusions on alien life in distant worlds.