https://archive.md/lQoIg
"Free-floating planets — dark, isolated orbs roaming the universe unfettered to
any host star — don’t just pop into existence in the middle of cosmic nowhere.
They probably form the same way other planets do: within the swirling disk of
gas and dust surrounding an infant star.
But unlike their planetary siblings, these worlds get violently chucked out of
their celestial neighborhoods.
Astronomers had once calculated that billions of planets had gone rogue in the
Milky Way. Now, scientists at NASA and Osaka University in Japan are upping the
estimate to trillions. Detailed in two papers accepted for publication in
The
Astronomical Journal, the researchers have deduced that these planets are six
times more abundant than worlds orbiting their own suns, and they identified
the second Earth-size free floater ever detected.
The existence of wandering worlds orphaned from their star systems has long
been known, but poorly understood. Previous findings suggested that most of
these planets were about the size of Jupiter, our solar system’s most massive
planet. But that conclusion garnered a lot of pushback; even scientists who
announced it found it surprising.
To better study these rogue worlds, David Bennett, an astronomer at the NASA
Goddard Space Flight Center, and his team used nine years of data from the
Microlensing Observations in Astrophysics telescope at the University of
Canterbury Mount John Observatory in New Zealand. Exoplanets were indirectly
detected by measuring how their gravity warped and magnified the light arriving
from faraway stars behind them, an effect known as microlensing.
With help from empirical models, the researchers worked out the spread of the
masses for more than 3,500 microlensing events, which included stars, stellar
remnants, brown dwarfs and planet candidates. (Data from one of those
candidates was compelling enough for the team to claim the discovery of a new
rogue Earth.) From this analysis, they estimate that there are about 20 times
more free-floating worlds in our Milky Way than stars, with Earth-mass planets
180 times more common than rogue Jupiters."
Via
Future Crunch:
<
https://futurecrunch.com/good-news-breastfeeding-trachoma-iraq-golden-lion-tamarin-brazil/>
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
