Stories
Slash Boxes
Comments

SoylentNews is people

posted by janrinok on Thursday March 22 2018, @02:03AM   Printer-friendly
from the water,-water,-everywhere dept.

TRAPPIST-1's exoplanets appear to have migrated closer to TRAPPIST-1 over time until they reached their current orbits. This migration appears to have allowed them to retain too much water to support life:

What [the ASU-Vanderbilt team] found through their analyses was that the relatively "dry" inner planets ("b" and "c") were consistent with having less than 15 percent water by mass (for comparison, Earth is 0.02 percent water by mass). The outer planets ("f" and "g") were consistent with having more than 50 percent water by mass. This equates to the water of hundreds of Earth-oceans. The masses of the TRAPPIST-1 planets continue to be refined, so these proportions must be considered estimates for now, but the general trends seem clear.

"What we are seeing for the first time are Earth-sized planets that have a lot of water or ice on them," said Steven Desch, ASU astrophysicist and contributing author.

But the researchers also found that the ice-rich TRAPPIST-1 planets are much closer to their host star than the ice line. The "ice line" in any solar system, including TRAPPIST-1's, is the distance from the star beyond which water exists as ice and can be accreted into a planet; inside the ice line water exists as vapor and will not be accreted. Through their analyses, the team determined that the TRAPPIST-1 planets must have formed much farther from their star, beyond the ice line, and migrated in to their current orbits close to the host star.

[...] "We typically think having liquid water on a planet as a way to start life, since life, as we know it on Earth, is composed mostly of water and requires it to live," Hinkel explained. "However, a planet that is a water world, or one that doesn't have any surface above the water, does not have the important geochemical or elemental cycles that are absolutely necessary for life."

Called it.

Also at Phys.org.

Inward migration of the TRAPPIST-1 planets as inferred from their water-rich compositions (DOI: 10.1038/s41550-018-0411-6) (DX) (arXiv)

Related: Powerful Solar Flares Found at TRAPPIST-1 Could Dim Chances for Life
TRAPPIST-1 Older than Our Solar System
Hubble Observations Suggest TRAPPIST-1 Exoplanets Could Have Water
Induction Heating Could Cause TRAPPIST-1 Exoplanets to Melt
Another TRAPPIST-1 Habitability Study


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Thursday March 22 2018, @06:16AM (2 children)

    by Anonymous Coward on Thursday March 22 2018, @06:16AM (#656496)

    If/when we meet intelligent life, I wonder if that intelligent life will even recognize us as intelligent.

    Unless they are too primitive to know that space probes which broadcast at them via directional antennae aren't a natural occurrence then they will notice.

    >inb4 what if they don't know about electromagnetism
    Then they're idiots or underdeveloped.

  • (Score: 0) by Anonymous Coward on Thursday March 22 2018, @08:24AM (1 child)

    by Anonymous Coward on Thursday March 22 2018, @08:24AM (#656520)

    Unless they are too primitive to know that space probes which broadcast at them via directional antennae aren't a natural occurrence then they will notice.

    >inb4 what if they don't know about electromagnetism
    Then they're idiots or underdeveloped.

    I recall an old comic where an ant explains to the other ants "we have looked for every known form of smell-based communication, and the conclusion is clear: There is no intelligent life up there".

    Your space probe will not look much different from a magnetic rock to any space faring species (that does not include us, our couple of visits to the local moon doesn't count). Electromagnetic communication is simply too slow to be useful. And we won't be able to detect their faster-than-light communication at all.

    • (Score: 0) by Anonymous Coward on Friday March 23 2018, @08:19AM

      by Anonymous Coward on Friday March 23 2018, @08:19AM (#657052)

      The gravitational field and the electromagnetic field are the only two fundamental fields in nature that have infinite range

      Sure we could be missing something, but there's probably not as many fundamental fields as there are possible molecules which can be practically smelled.