The space rock looks more or less like a propeller

Oct 4, 2011 12:23 GMT  ·  By

A team of astronomers from the Queens University Belfast (QUB), led by Dr. Pedro Lacerda, announced the analysis of a very weird object in the Kuiper Belt, a space rock that looks and spins like a propeller. The findings were presented at a meeting yesterday.

Another interesting aspect of Kuiper Belt object 2011QC298 is that it's tilted at roughly 90 degrees from the elliptic plane of the solar system. What this implies is that other companions may also be tilted at these extravagant angles.

Details of the space rock and the research that led to the new conclusions were presented yesterday, October 3, at the Joint Meeting of the European Planetary Science Congress and the Division for Planetary Sciences, held in Nantes, France.

Astronomers explain that the Kuiper Belt is a disk of rocks orbiting beyond the orbit of Neptune. The dwarf planets Pluto, Haumea, Eris and Makemake are all parts of this belt, as are other objects of varying sizes, including 2001QC298.

What is very interesting about this particular structure is that it's made up of two different objects, which may or may not be touching as they whirl past each other. Dr. Scott Sheppard and professor David Jewitt were the first to discover it, back in 2004.

The thing that attracted the astronomers to this particular rock formation was that fact that its apparent brightness seemed to triple every 7 hours, indicating an irregular shape. “Imagine that you glue two eggs together tip to tip - that's approximately the shape of 2001QG298,” Lacerda said.

“It looks a bit like an hourglass,” he added. “The object is so distant that we cannot resolve its shape. But this brightness oscillation, called a lightcurve, reveals the strange shape of 2001QG298 as it spins round,” the astronomer said at the conference.

This explains the reoccurring dip in brightness the team is seeing. When the object appears faint, this is because one of its components moves behind the other, decreasing the total surface that reflects sunlight back into telescope detectors.

“As the hidden component rotates back into view, we can see the full hour-glass shape. The reflecting area increases and the whole thing looks brighter,” Lacerda told attendants at the meeting.

Assuming the existence of randomness in the tilts of Kuiper Belt objects (KBO), astronomers propose that as many as 10 percent of the total number of space rocks beyond the orbit of Neptune are double KBO, Daily Galaxy reports.

“It was a surprise to find that 2001QG298 is inclined by 90 degrees, but that's not the first time we've seen this in a contact binary. There is another famous doublet object, a large Trojan asteroid called 624 Hektor. That object is also tilted almost 90 degrees,” Lacerda concluded, quoted by SOTT.