Category: Small SS Objects

Probing the Mysteries of 50000 QUAOAR

Hundreds of millions of miles beyond the orbit of Neptune lurks one of the most intriguing objects in the Solar System, 50000 Quaoar.

The Mighty 50000 Quaoar

50000 Quaoar is notable for multiple reasons, but the most apparent is its name. Quaoar is the name of the creator deity of the Tongva people in the Los Angeles Basin. The deity Quaoar was believed to have control of a group of “avengers” who spied on humanity and enforced Quaoar’s will. While 50000 Quaoar certainly has an impressive namesake, the 50000 portion is also interesting from an astronomical point of view.

Ordinarily, Solar System objects will be named along with a number denoting how many similar objects had been found before. For instance, 1154 Astronomia was the 1154th minor planet found in the solar system. This chart has all of the minor planets found in order. But for a Solar System object as interesting as Quaoar, scientists decided to break entirely with this tradition to give it a number more fitting to its power; thus we have 50,000 Quaoar.

Another interesting fact concerning Quaoar is that it is a cubewano, and despite the fact that WordPress has underlined it in red on my screen, this strange term cubewano is really an English word. It comes from the provisional name of trans-Neptunian object 15760 Albion, 1992 QB1. 1992 QB1 was left unnamed for over two decades, so whenever another trans-Neptunian object was located it was named after this provisional name (if you say QB1 fast enough it begins to sound like cubewano).

Cubewanos are often very large. The largest of them Makemake is actually a dwarf planet, although this isn’t unique to Makemake. 50000 Quaoar may also be a dwarf planet, and it even has its own 50 km moon, Weywot.

50000 Quaoar looking menacing

Some scientists have hypothesized that 5000 Quaoar was originally much larger and collided with another trans-Neptunian object, possibly even Pluto. Quaoar has also been chosen as a target for a flyby in the 2030s, so get your tickets soon.

The OORT CLOUD and You

You might find yourself looking at a (to-scale) diagram of the planets of the solar system (and Pluto), such as the following:

A solar system model that suspiciously does not include earth…

and think to yourself “Wow, Pluto is so much farther out from the sun than the Earth is. The solar system is so massive!”. And while you would be correct in your statement, the orbits of the sun’s outer planets (and dwarf planets) pale in comparison to the true extent of our solar system. Enter: the OORT CLOUD.

Actually, the Oort Cloud is going to have to wait. First, we’re going to have to cover comets. For a comet to show its characteristic tail, it has to pass (relatively) close to the sun. This implies that its orbit must be highly elliptical so that it can be near the sun for a short period of time before moving far enough away that it reverts to its less aesthetic ball-of-ice-and-rock form.

Everyone knows about Halley’s comet, which becomes visible from Earth every 76 years. Combining this lengthy period with the above fact that comet orbits must be very elliptical, one can imagine that Halley’s comet is, at its furthest extent away from the sun, far away. An in fact it manages to reach a bit farther than the orbit of Neptune before crashing back toward the sun.

Halley’s comet

But, in the grand scheme of things, Halley’s comet actually has a fairly short period. The famous Hale-Bopp comet has a period of over 2500 years and, as you might guess, reaches much farther away from the sun than Halley’s comet: 183 AU, or roughly 6 times farther than Neptune’s Aphelion.

But wait, there’s more! This unassuming ball of rock:

Sedna

is Sedna, a minor planet whose aphelion is 936 AU, or 30 times Neptune’s aphelion.

But even beyond Sedna, there is the Oort Cloud. The Oort Cloud is a theoretical cloud of gas and icy bodies which exists at the very edge of the Sun’s gravitational influence. This cloud is conjectured to exist at up to 200,000 AU away from the sun. In other words, the outer reaches of the Oort Cloud, should it exists according to these projected specifications, would be over six thousand times farther away from from the sun is than Neptune. This is the true extent of our solar system, beyond which point the sun’s gravity is no longer sufficient to pull bodies along with it as it wanders through the galaxy.

Comparison of the inner solar system versus the inner Oort Cloud.