"Study Suggests Most Common Outer Planets Likely Neptune-mass" Topic

A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems. The study provides the first indication of the types of planets waiting to be found far from a host star, where scientists suspect planets form most efficiently.

"We've found the apparent sweet spot in the sizes of cold planets. Contrary to some theoretical predictions, we infer from current detections that the most numerous have masses similar to Neptune, and there doesn't seem to be the expected increase in number at lower masses," said lead scientist Daisuke Suzuki, a post-doctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland Baltimore County. "We conclude that Neptune-mass planets in these outer orbits are about 10 times more common than Jupiter-mass planets in Jupiter-like orbits."

Gravitational microlensing takes advantage of the light-bending effects of massive objects predicted by Einstein's general theory of relativity. It occurs when a foreground star, the lens, randomly aligns with a distant background star, the source, as seen from Earth. As the lensing star drifts along in its orbit around the galaxy, the alignment shifts over days to weeks, changing the apparent brightness of the source. The precise pattern of these changes provides astronomers with clues about the nature of the lensing star, including any planets it may host. […]

Cheers,
Martin from Canada

It is scary sometimes, when you look at the average how regimented the universe can be.

What I find Way Cool is that 30 years ago a rational argument could be made that ours was the only Solar System.
Now, we aren't even bothering to name the "new" planets (with a name), and we can predict their probable structure. .

Winston that is weird. I have an astronomy textbook from the 1970s (my moms college textbook). It very clearly talks about other Solar Systems than just Sol.

Data Winston, data, and the Law of Large Numbers. We have more data, and the Law of Large numbers has validity anywhere in this universe (no idea about other universes).

What I find Way Cool is that 30 years ago a rational argument could be made that ours was the only Solar System.

We apparently went to different schools. 37 years ago (when I received my BSc.'79) I was taught that there were probably planet containing solar systems everywhere. However, with the technology of the time, the planets were too small and too far away to be seen.

The technology has come a long way. Wiki says that a mere 9 years after the above date, the first exoplanet was discovered. But I agree, it is WAY Cool!