D7- Q said the clock started. This was coincidentallly the NEW Moon, the darkest phase. Interestingly, military love to begin attacks on the NEW moon.
D22 is the FULL Moon according to my calendar, which could be wrong(wall calendar).
Unknown treasure trove of planets found hiding in dust
Date:
December 7, 2018
Source:
University of Arizona
Summary:
The first unbiased survey of protoplanetary disks surrounding young stars in the Taurus star-forming region turned up a higher-than-expected number of disks with features suggesting nascent planets, according to a new study.
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The Taurus Molecular Cloud, pictured here by ESA's Herschel Space Observatory, is a star-forming region about 450 light-years away. The image frame covers roughly 14 by 16 light-years and shows the glow of cosmic dust in the interstellar material that pervades the cloud, revealing an intricate pattern of filaments dotted with a few compact, bright cores – the seeds of future stars.
Credit: ESA/Herschel/PACS, SPIRE/Gould Belt survey Key Programme/Palmeirim et al. 2013
"Super-Earths" and Neptune-sized planets could be forming around young stars in much greater numbers than scientists thought, new research by an international team of astronomers suggests.
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Observing a sampling of young stars in a star-forming region in the constellation Taurus, researchers found many of them to be surrounded by structures that can best be explained as traces created by invisible, young planets in the making. The research, published in the Astrophysical Journal, helps scientists better understand how our own solar system came to be.
Some 4.6 billion years ago, our solar system was a roiling, billowing swirl of gas and dust surrounding our newborn sun. At the early stages, this so-called protoplanetary disk had no discernable features, but soon, parts of it began to coalesce into clumps of matter – the future planets. As they picked up new material along their trip around the sun, they grew and started to plow patterns of gaps and rings into the disk from which they formed. Over time, the dusty disk gave way to the relatively orderly arrangement we know today, consisting of planets, moons, asteroids and the occasional comet.
Scientists base this scenario of how our solar system came to be on observations of protoplanetary disks around other stars that are young enough to currently be in the process of birthing planets. Using the Atacama Large Millimeter Array, or ALMA, comprising 45 radio antennas in Chile's Atacama Desert, the team performed a survey of young stars in the Taurus star-forming region, a vast cloud of gas and dust located a modest 450 light-years from Earth. When the researchers imaged 32 stars surrounded by protoplanetary disks, they found that 12 of them – 40 percent – have rings and gaps, structures that according to the team's measurements and calculations can be best explained by the presence of nascent planets.
"This is fascinating because it is the first time that exoplanet statistics, which suggest that super-Earths and Neptunes are the most common type of planets, coincide with observations of protoplanetary disks," said the paper's lead author, Feng Long, a doctoral student at the Kavli Institute for Astronomy and Astrophysics at Peking University in Bejing, China.
While some protoplanetary disks appear as uniform, pancake-like objects lacking any features or patterns, concentric bright rings separated by gaps have been observed, but since previous surveys have focused on the brightest of these objects because they are easier to find, it was unclear how common disks with ring and gap structures really are in the universe. This study presents the results of the first unbiased survey in that the target disks were selected independently of their brightness – in other words, the researchers did not know whether any of their targets had ring structures when they selected them for the survey.
"Most previous observations had been targeted to detect the presence of very massive planets, which we know are rare, that had carved out large inner holes or gaps in bright disks," said the paper's second author Paola Pinilla, a NASA Hubble Fellow at the University of Arizona's Steward Observatory. "While massive planets had been inferred in some of these bright disks, little had been known about the fainter disks."