by Mark Thompson
October 28, 2011
There's a strange
brightening in the Uranian atmosphere and amateur
astronomers can help investigate what it is.
Of all the planets in our solar system, I'm usually guilty of
thinking poor old Uranus is pretty bland and uninteresting.
In fact, the only interesting things I can ever think to say about
it are that it orbits the sun on its side... and has a pretty
exciting story attached to its discovery.
As this 2004 infrared
Keck telescope image shows, Uranus is tilted,
plus it has structure
in its atmosphere. It even has a ring system.
Not so boring now, is
it. Click to enlarge this image.
Wisconsin-Madison), Keck Observatory
Something exciting has happened on Uranus!
Uranus, like the other giant planets in the solar system (Jupiter,
Saturn and Neptune), is made up almost entirely of gas, although it
differs in composition to Jupiter and Saturn - it has higher
quantities of water, methane and ammonia ices. Unlike conventional
ice, it's a super dense liquid.
Uranus, like Neptune (below video), is
often referred to as an "ice giant."
Uranus measures a mighty four-times the diameter of Earth and orbits
the sun at an average distance of 2.9 billion kilometers (around 20
times the Earth-sun distance).
From that distance it's only just
visible to the naked eye under dark skies, but telescopes are needed
to see any detail.
Nearer planets seem to receive more attention from amateur
astronomers but that may be about to change.
An image taken by planetary scientist Larry Sromovsky, with
the Gemini 8.1 meter telescope shows a bright patch that is thought
to be an eruption of methane ice high in the atmosphere.
Leading planetary scientist Heidi B. Hammel used her Facebook
page to announce the discovery and to appeal for further
Amateur astronomers with advanced
equipment are being asked to make observations of the planet and, if
enough confirmations are received, it may lead controllers of the
Hubble Space Telescope to interrupt observations and take a closer
Understanding the nature of this spot is important, Hammel explained
to Discovery News.
"The reason we care about the clouds
on the planet Uranus is that they seem to be seasonally driven,"
said Hammel. "Uranus spins tipped over on its side, giving rise
to extreme changes in sunlight as its seasons progress.
"The changes are therefore much more dramatic than for other
planets. Uranus thus gives us unique insight into the energy
balance in a planetary atmosphere."
It's almost like a weather system on
steroids, as the northern hemisphere receives 42 years of sunlight
and constant energy from the sun with the southern hemisphere
plunged into 42 years of darkness.
Unfortunately, this new outburst may be just out of reach of most
amateur astronomers but those with more advanced equipment should
certainly take a look.
It seems fitting that 230 years since the planet was discovered by
Herschel, himself an amateur astronomer, it may be the work of
modern day amateurs that unlock clues to the nature of Uranus'
strange atmospheric effects.