Hubble Discovers Moon Orbiting Dwarf Planet Makemake In Outer Solar System

NASA astronomers have discovered a small moon orbiting Makemake, one of the five dwarf planets of our solar system. The discovery was made after scientists focused the Hubble Space Telescope at Makemake for over two hours in April 2015, according to a recent report by NASA. 

The moon, nicknamed MK 2, measures around 160 kilometers across and is as dark as charcoal. The satellite is 1300 times fainter than Makemake which explains the reason for its obscurity until now, as it hidden by the bright light of its parent planet. Astronomers are still not clear about the shape of MK 2's orbit; however they are speculating that the moon orbits Makemake at a minimum distance of 21,000 kilometers. According to the NASA report, it has been further suggested that MK 2 takes at least 12 days to circle around the dwarf planet.

Researchers will be able to calculate the mass of the Makemake/MK 2 system, as well as the materials which make up the objects, after in-depth observations in the future. The history of the pair is yet to be determined. A dramatically elongated orbit would suggest that the satellite was gravitationally captured by the dwarf planet, long after each formed in separate areas of space. A circular orbit would support the theory that the pair formed together.

Makemake, which was discovered in 2005, orbits the sun once every 310 years. The reddish dwarf planet is shaped like a flattened sphere that measures around 1400 kilometers across and it is located in the Kuiper Belt, the icy debris belt beyond Neptune's orbit. Discovering a satellite orbiting the planet has new implications for astronomers.

When Makemake was first spotted, scientists observed that the planet was continually bright which implied that its surface was uniformly covered in reflective and bright ices. However, Makemake's heat signatures were slightly varied that suggested the presence of at least one dark and warm patch on its surface. Astronomers failed to understand the relation between the two sets of data, as a dark patch was never noticed during observations. As per the NASA report, with the discovery of MK 2, it has now been understood that the dark patch was not present on the dwarf planet's surface but rather in its orbit, which accounted for the previous thermal measurements.