Pebble-Sized Rocks Near Orion Nebula May Jump-Start Planet Formation

Planets in our universe start out as microscopic bits of dust. Now, scientists have found out that the Orion Nebula may just be brimming with pebble-sized particles that could jump start planet formation. The findings could mean that researchers are witnessing the very start of planet formation in this nebula.

In this case, the scientists used the Green Bank Telescope in order to examine filaments of star-forming gas near the Orion Nebula. Within this gas are the particles, which are 100 to 1,000 times larger than the dust grains found around protostars. It's very possible that these dense ribbons of rocky material may represent a new mid-size class of particles that may help with creating planets.

"The large dust grains seen by the GBT would suggest that at least some protostars may arise in a more nurturing environment for planets," said Scott Schnee, one of the researchers, in a news release. "After all, if you want to build a house, it's best to start with bricks rather than gravel, and something similar can be said for planet formation."

Early maps of the northern portion of the Orion Molecular Cloud Complex, a star-forming region, made with the IRAM 30 meter radio telescope in Spain caused astronomers expect to find a certain brightness to the dust emission when they observed the filaments at slightly longer wavelengths with the GBT. Instead, though, the astronomers found that the region shone much bright than expected in millimeter-wavelength light.

"This means that the material in this region has different properties than would be expected for normal interstellar dust," said Schnee. "In particular, since the particles are more efficient than expected at emitting at millimeter wavelengths, the grains are very likely to be at least a millimeter, and possibly as large as a centimeter across, or roughly the size of a small Lego-style building block."

So where did these grains come from in the first place? It's possible that the filaments in the Orion Molecular Cloud Complex helped the dust grains grow to such unusual proportions. The other option is that the rocky particles originally grew inside a previous generation of cores, or perhaps even protoplanetary discs. The material could have escaped back into the surrounding molecular cloud instead of becoming part of a newly forming star system.

The findings reveal a little bit more about this region and show that one day, it could birth new planets.  That said, more observations need to be taken in order to confirm the findings.

The findings are published in the journal Monthly Notices of the Royal Astronomical Society.