On my wall, I have a painting with the Neil Gaimen quote: A world in which there are monsters, and ghosts, and things that want to steal your heart is a world in which there are angels, and dreams and a world in which there is hope. 

I love this quote, but it only seems to apply to our actual world and not the universe around us. Space is trying to kill us and every other planet out there.

Observations taken by the Spitzer Space Telescope of the young star HD 166191 revealed the violent actions of toddler planets wailing on one another. Spitzer took roughly 100 observations of this 10 million-year-old star between 2015 and 2018. This young system hasn’t yet formed full-fledged planets, but it does have large asteroid or dwarf planet-sized planetesimals that are sometimes colliding in ways that stick them together and are sometimes colliding in ways that smash them apart.

According to a NASA release on these observations: In mid-2018, the space telescope saw the HD 166191 system become significantly brighter, suggesting an increase in debris production. During that time, Spitzer also detected a debris cloud blocking the star. Combining Spitzer’s observation of the transit with observations by telescopes on the ground, the team could deduce the size and shape of the debris cloud. Their work suggests the cloud was highly elongated, with a minimum estimated area three times that of the star. However, the amount of infrared brightening Spitzer saw suggests only a small portion of the cloud passed in front of the star and that the debris from this event covered an area hundreds of times larger than that of the star.

Over time, this cloud of material expanded, and the dust became distributed throughout the system.

Spitzer looked at this system specifically because researchers hoped this kind of beautiful destruction would be common enough that they would catch it happening. And they did; collisions are simply in the nature of young solar systems. This research is published in a new paper in The Astrophysical Journal led by Kate Su, who says: By looking at dusty debris disks around young stars, we can essentially look back in time and see the processes that may have shaped our own solar system. Learning about the outcome of collisions in these systems, we may also get a better idea of how frequently rocky planets form around other stars.

This seems like a good time for a reminder that we have our Moon because something roughly the size of Mars struck the young, smaller Earth, and the heavier stuff largely formed Earth while the lighter stuff splashed up and formed our Moon. We are the product of the kinds of collisions Spitzer was observing.

More Information

NASA press release

“A Star-sized Impact-produced Dust Clump in the Terrestrial Zone of the HD 166191 System,” Kate Y. L. Su et al., 2022 March 10, The Astrophysical Journal