Hubble spots ice moon orbiting dwarf planet Makemake
Pluto-like object possesses Pluto-like moon
The Hubble telescope has spotted an ice moon orbiting the dwarf planet Makemake.
Makemake (pronounced mar-kee mar-kee) is 1400 kilometres in diameter and is the second brightest dwarf planet behind Pluto. It resides in the Kuiper Belt and is one of five dwarf planets to be recognised by the International Astronomical Union. It's newly-found moon, dubbed MK 2, is some 1300 times fainter than its parent and is a mere 160 kilometres in diameter.
Hubble’s Wide Field Camera 3 found MK 2 in April last year thanks in part to its ability to detect faint objects near bright objects. MK2 is the first moon found at Makemake.
Lead image analyser research scientist Dr Alex Parker of Southwest Research Institute, Boulder, Colorado, says the team used the same technique employed to observe Pluto's small satellites.
“Makemake is in the class of rare Pluto-like objects, so finding a companion is important,” Parker says.
“The discovery of this moon has given us an opportunity to study Makemake in far greater detail than we ever would have been able to without the companion.”
Dr Parker says MK 2's orbit appeared to be "edge-on" such that the moon is lost in Makemake's glare.
Astro-boffins now hope to compare Makemake and Pluto, a rare chance to compare similar bodies in the outer solar system.
Preliminary analysis indicates the moon orbits Makemake in about 12 days. It's hypothesised that MK 2 was captured from the Kuiper Belt, or came into being after a collision in the deep past.
The discovery may also solve an open question about irregular surface temperature on Makemake, which now have the neat explanation of the moon's shadow.