Jupiter Drops Its Belt, Gets “Grounded”

The tug-of-war between space-based and ground-based telescopes continues, with today’s release of what’s being called the sharpest full-planet image of Jupiter taken by an on-the-ground observatory.


—Image courtesy ESO



Jupiter, as seen by the Hubble Space Telescope in 2007

—Image courtesy NASA, ESA, and the Hubble Heritage Team (AURA/STScI)

An international team used the ESO’s Very Large Telescope in Chile to stare right at Jupiter for almost two hours straight.

The resulting infrared image revealed that Jupiter has lowered its belt. The bulk of the haze within the bight band around Jupiter’s midsection has migrated south by more than 3,700 miles (6,000 kilometers) since 2005, the researchers said.

“The change we see in the haze could be related to big changes in cloud patterns associated with last year’s planet-wide upheaval, but we need to look at more data to narrow down precisely when the changes occurred,” team member Mike Wong said in a press release.

[Incidentally, the global upheaval he’s referring to involved massive changes in cloud patterns and other wild weather features observed in 2007.]

In an interview with NatGeo News reporter Richard A. Lovett, lead researcher Franck Marchis, a planetary astronomer at the University of California, Berkeley, and the SETI Institute, said of the new image: “We have something comparable to or even better than the Hubble Space Telescope.”

Wow. But this isn’t the first time researchers using ground-based ‘scopes have compared their work to products of the aging but much beloved Hubble.

When it launched in 1990, the orbiting telescope was quite a coup for astronomy, because even the most powerful lenses on Earth tended to get blurry images of objects thanks to the same turbulence in the planet’s atmosphere that makes stars twinkle poetically.

In recent years, however, astronomers have been finding ways to correct for atmospheric distortion, and some of their efforts have rivaled space-based observatories for sharpness—if not always for aesthetics.

In Jupiter’s case, the new image used a computer-assisted technique called Multi-Conjugate Adaptive Optics Demonstrator, or MAD.

The process involves correcting distortions by comparing them to shifts in so-called guide stars, ones with precisely known locations. Using many guide stars allowed the MAD team to remove blur from a field of view 30-times larger than any previous effort, so that the new image shows details as small as 180 miles (300 kilometers) across.

But how sharp is sharp enough, and will Earthly observatories ever surpass orbiters and other space probes for level of detail?

Cost is certainly an issue, as Hubble has shown that getting a ‘scope into space and then keeping it running can come with a hefty price tag.

If we can do the same looking for less moolah, that’s government dollars that could be funneled to other parts of science, which, even when recession isn’t looming, often feels like the least favorite player in any game of fund-my-project (ahem, bear DNA).

Right now I kinda feel like no matter how many guide stars you have, there’s always going to be room in astronomy for sending a robot—or maybe a human—into space for exploration purposes, even if it’s just to take a few in-person family portraits.


Charles Conrad Jr., Apollo 12 Commander, during the mission’s second lunar walkabout in 1967.

—Image courtesy NASA

I guess the big question will be whether groundbreaking advances like the new ESO image mean that we send the bulk of our future sciencey tax dollars to the mountaintops rather than the heavens.

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