Getting up close with Jupiter

It has a weird, pale centre, and rotation. And it looks as if it8217;s been gaining strength.

It8217;s been given a name: Oval BA. But it won8217;t be making landfall. Ever. Because on Jupiter, where this storm is raging, there is no land.

Astrophysicist Amy Simon-Miller of the NASA Goddard Space Flight Center in Greenbelt, Maryland, has been eyeing Oval BA for months, along with excited Jupiter-watchers around the world.

Last spring, they got the managers of the Hubble Space Telescope to focus on the storm, and now the Laurel, Maryland-based operators of a satellite bound for Pluto plan to aim a special onboard digital camera/telescope at Jupiter as the spacecraft hurtles past it early next year.

Jupiter, which has no real surface, is known for having some of the worst weather in the solar system. It also has certain cycles that Simon-Miller says are similar to Earth8217;s and may hold clues to weather and climate change here.

But most days, Jupiter8217;s forecast is nothing like ours. The normal wind velocity is 200-300 mph, Simon-Miller said. 8220;Unlike here, where the winds change from day to day, on Jupiter they8217;re pretty much the same every day,8221; she said. 8220;Compared to Earth, it8217;s a much windier day, pretty much everywhere.8221;

The planet8217;s legendary swirling overcast looks like something painted by Van Gogh. And Jupiter already boasts the so-called Great Red Spot, an even bigger storm that8217;s been raging for centuries.

The Jovian atmosphere is mostly hydrogen and helium. There is lightning8212;scientists think the bolts are probably mammoth8212;and there may be ammonia-laced rain. The Galileo space probe that descended via parachute toward the surface in 1995 was crushed by the atmospheric pressure.

Conditions on Jupiter are indeed 8220;unpleasant8221;, said Simon-Miller, 35, who is fascinated by its atmosphere. She said there are places around the planet where the wind velocity is probably low, and there are a few breaks in the clouds. But the sun is 483 million miles away8212;five times as far as the Earth is from the sun.

Elsewhere in the solar system, scientists say, it8217;s actually breezier. On Neptune, winds top 1,000 mph; and on Saturn, there is another strange, rotating storm that is smaller than Jupiter8217;s new red one.

Simon-Miller said Oval BA, now known as the Little Red Spot, was formed in 2000 out of three smaller systems but was noticed changing hues about a year ago. 8220;I was really shocked,8221; she said. 8220;We8217;ve never seen a big storm like that turn red.8221;

Experts think the storm became more intense and wind velocity increased. 8220;We8217;re still trying to figure out exactly what changed in it, why it8217;s red, what makes it red,8221; she said, adding that scientists don8217;t know why the Big Red Spot is red.

Simon-Miller, the lead author of a recent article about the new storm in the journal Icarus, said the system is somewhat like a hurricane. It has a hazy, pale core where the wind velocity is lower, and it has banding and some spiral structure.

But unlike hurricanes, which are low-pressure systems, Oval BA is a high-pressure monster that seems to be pulling material up and out from its centre, she said. It is rotating counterclockwise and drifting eastward about 10 mph, but its fury is undiminished by contact with land. 8220;In Jupiter8217;s case, we don8217;t have land,8221; Simon-Miller said. The planet has a solid core but is mostly gas.

New Horizons, launched in January, is outbound at about 45,000 mph on a nine-year journey to Pluto. It will pass by Jupiter in February to pick up a gravity assist, which will fling it farther on its way.

But as it approaches next month, New Horizons will start taking snapshots, and the managers have decided to aim its hi-tech telescope camera directly at Oval BA for a few hours as the craft rockets past. The images should be 10 times better than the Hubble8217;s, Simon-Miller said: 8220;We8217;re going to get some pretty spectacular data 8230; just because it8217;s going to be such high resolution.8221;

Andrew Cheng, of the Johns Hopkins laboratory, is the principal investigator for the telescope/camera, called LORRI, for Long Range Reconnaissance Imager. 8220;We8217;re getting a very close-up view of the Little Red Spot,8221; he said. 8220;We8217;re going to do it one or two days out. 8230; We should see a lot of detail and get a better idea of how the winds are circulating and how the clouds are circulating inside it.8221;

8212;The Washington Post / Michael E. Ruane