June 18, 2019

24.04.10-Our Existence: Justified.

The formation of the Earth poses a key dilemma to planetary accretionary theory; namely, why are we here at all? Standard models would say that the Earth and other planets coalesced out of the proto-solar nebula to form. However, spiral density waves within the same nebula should have drawn down orbital energy to shorten the planets orbit, slowly drawing it in. Looking at other “hot Jupiter” systems, that’s just what we see; large gas giant worlds that formed further out, only to migrate inward into tight orbits… just how did we end up in our nice, neat orbit?

Now, computational astrophysicist Mordecai-Mark Mac Loc at the American Museum of Natural History may have the answer. Accounting for temperature and spin variability, resonance key holes can occur; planets like Earth may simply spiral inward and get hung up in these safe zones between dragging pressure waves. Of course, a majority of proto-planets don’t make the cut and simply spiral inward to a fiery end, but they’re not around for us to see today. One discovery that would perhaps give observational weight to this theory would be the discovery of exo-Earths also parked in nice neat orbits… the Kepler space telescope may pave the way for this discovery as it stares off into Cygnus. For now, thank computational mathematics that you’re here reading this, just as it says you should be!

27.10.09: Exploring Shiva Crater.

Move over, Chicxulub; we may have a new contender in the realm of cosmic extinction events. Recently, paleontologist Sankar Chatterjee of Texas Tech University has dubbed a ring shaped subsurface structure off of the western coast of India Shiva crater. If Chaterjee is correct, it would be one of the largest impact basins on Earth recorded, at a diameter of about 500 km wide. Aptly named after the Hindu goddess of destruction, Shiva would have been caused by an asteroid or comet of about 40 km in diameter. Chaterjee has been following data accrued by decades of off-shore oil drilling projects in the area; the existence of iridium deposits suggests a calamity of cosmic origin. Rare on Earth but common on asteroids, the element iridium was considered a “smoking gun” in dating the aforementioned K-T extinction event of about 65 million years ago. Tantalizingly, the Shiva Crater event also seems to date from the same era. This raises the question; could a hail of cometary debris have been common in that far gone time? Bodies without rapid erosion, such as our Moon or Mars, should show evidence of impacts dating from around this epoch. Of course, the crater hypothesis is not without its critics…the area surrounding the Indian subcontinent is very geologically active as it pushes under the plates of the Asian continent. In particular, an area known as the Deccan Traps extends to the edge of Shiva and was very active during the Cretaceous period. Also, Shiva appears to have rock from the Earth’s underlining mantle exposed, again tantalizing evidence for a past cataclysm… this area of our own near space begs for further exploration!