In the shadow of Mars going viral, Uranus and Neptune haven’t really gotten much publicity—but that’s about to change.
NASA now wants to find out more what lies beneath the eerie bluish glow of these less popular planets. The composition, internal structure and levels of heavy elements on Uranus, plus its energy fields and weather phenomena, are turning astronomers to the outer reaches of our solar system. Mysterious moons Miranda, Ariel, Umbriel, Titania, and Oberon sound as intriguing as the fictional fairies they’ve been named for (the more minor moons floating around also have fairy names). What is much more interesting to the space agency than satellites that sound like they flew out of A Midsummer’s Night Dream is what we could find on each of these micro-worlds. Neptune’s largest moon, Triton, was possibly snatched from the Kuiper Belt and is thought to erupt with geysers beneath its thin atmosphere.
“Compared to Neptune, Uranus has a larger satellite system that likely formed in a disc around the planet (like the Jupiter and Saturn satellite systems), which is helpful for comparative planetary science,” said Jonathan Fortney, a UC Santa Cruz astronomy and astrophysics professor who is eager to see a mission blast off to Uranus.
With all the exoplanet discoveries that have been orbiting social media lately, Neptune has caught the space agency’s telescopic eye because so many of them are so close in size. Our eighth planet’s origins could tell us why gas planets that massive are so abundant in alien skies.
Bringing the formation of our own outer planets out of the dark could also illuminate differences between the cosmic DNA of gas giants and ice giants that made one type of planet outnumber the other.
The essentials for any one of the four proposed missions that ultimately takes off to Uranus or Neptune would be a camera, magnetometer, and Doppler imager. Sending an orbiter equipped with an atmospheric probe to either planet is seen as ideal for atmospheric and magnetospheric study as well as zeroing in on the mysteries of those fairy moons. An alternate option among the four proposed missions would send an orbiter loaded with instruments that would image objects in UV and the infrared, detect plasma and dust, and be capable of microwave radar. Yet another hypothetical mission would include a Uranus flyby with a trio of orbiters, a probe to measure the gas and heavy element levels in the atmosphere, and a narrow-angle camera to get an eyeful of its moons.
Of course there are going to be challenges. You saw that coming. The future spacecraft will need nuclear power, because its 14-year journey will propel it too far away from the sun for a solar power boost. This makes NASA nervous, because international restrictions have made the required plutonium-238 atomic batteries rare. Possibilities for Jupiter gravity assists narrow the launch window for Neptune to no later than 2030, while a Uranus mission needs to take off by 2034.
(via New Scientist)