Thursday, August 06, 2015

Sedna: One of the Exoplanets in our own Solar System?


Turns out, our seemly placid star had a criminal youth of cosmic proportions.

A recent study out from Leiden Observatory and Cornell University may shed light on the curious case of one of the solar system’s more exotic objects: 90377 Sedna.

A team led by astronomer Mike Brown discovered 90377 Sedna in late 2003. Provisionally named 2003 VB12, the object later received the name Sedna from the International Astronomical Union, after the Inuit goddess of the sea.

From the start, Sedna was an odd-ball. Its 11,400 year orbit takes it from a perihelion of 76 astronomical units (for context, Neptune is an average of 30 AUs from the Sun) to an amazing 936 AUs from the Sun. (A thousand AUs is 1.6% of a light year, and 0.4% of the way to Proxima Centauri, the closest star to our solar system). Currently at a distance of 86 AU and headed towards perihelion in 2076, we’re lucky we caught Sedna as it ‘neared’ (we use the term ‘near’ loosely in this case!) the Sun.

But this strange path makes you wonder what else is out there, and how Sedna wound up in such an eccentric orbit.

1 comment:

Anonymous said...

Huh. So nearly 1000 possible planet like things hiding out in that region? Guess all those people who thought there were planet things out there were right. Considering how they zip by the Kupiter belt, not surprising if they could toss comets into the inner solar system. All the more reason one needs a big beefy gas gaint bodyguard for their life filed rocky inner world.