Monthly Archives: July 2009

Gemini Observatory, impacts, planetary science

Jupiter’s Southern “Bruise”

2 Comments

As Seen by Gemini Observatory

The impact site of Jupiter, as seen by Gemini Observatory. It looks similar to the Shoemaker-Levy 9 crash sites that appeared in 1994 after the impact of that comet with Jupiters cloud tops.
The impact site of Jupiter, as seen by Gemini Observatory. It looks similar to the Shoemaker-Levy 9 crash sites that appeared in 1994 after the impact of that comet with Jupiter's cloud tops. (Click to embiggen.)

As more observatories turn their attention to the bruise at Jupiter’s southern polar region, the images just keep getting better.  Today’s release from Gemini Observatory on Mauna Kea in Hawai’i shows a composite mid-infrared view of the impact site (the bright yellow pair of blobs at the bottom center of the image at left).

This is looking more and more like the SL-9 crash effects from 1994, a point that SL-9 veteran Heidi Hammel pointed out as she described what they see in the images. “The morphology is suggestive of an arc-like structure in the feature’s debris field,” she added.

The mid-infrared wavelength image is showing the effect of scattered material as a result of this most recent impact.  It’s likely that the impactor was a small (hundreds of meters across) comet or asteroid — not something that could have been seen from Earth even with powerful telescopes.

The Gemini images that  made up the composite were obtained with the MICHELLE spectrograph/imager. This gave a series of images at seven different mid-infrared wavelengths. Two of the images (8.7 and 9.7 microns) were combined into a color composite image by Travis Rector at the University of Alaska, Anchorage to create this final false-color image. By using the full set of Gemini images taken over a range of wavelengths from 8 to 18 microns, the team will be able to disentangle the effects of temperature, ammonia abundance, and upper atmospheric aerosol content so that they can understand just what it was that plowed into Jupiter and what chemical elements it contained. Comparing these Gemini observations with past and future images will permit the team to study the evolution of features as Jupiter’s strong winds disperse them.

This image is one of those “target of opportunity” sets that observatories plan for when they allocate time each year. Essentially, the planning committees put aside time “just in case” something happens — just like it did with this impactor at Jupiter. As scientist Imke de Pater noted, “the Gemini support staff made a heroic effort to get these data.”  The Gemini team (Tom Geballe, Chad Trujillo, Rachel Mason and Paul Hirst, aided by Glenn Orton and Leigh Fletcher (of JPL)) swung into action immediately, making the telescope available within 24 hours of the request for observing time. It’s important to get data as soon as possible during these types of events, which are “transient” — meaning that they and their effects don’t last long, and the evidence for whatever the impactor was gets dissipated pretty quickly.  For more details on this Gemini image, swing your attention to the impact’s image page at Gemini’s website.

Update:  I heard that HST has also looked at this site as a target of opportunity. Not sure exactly when in the next day or so the image(s) will be available, but whatever shows up should be spectacular!

mauna kea, Thirty Meter Telescope

Another Telescope for Mauna Kea

Leave a comment

The Thirty Meter Telescope Finds a Home

An artists concept illustration of the Thirty Meter Telescope. Courtesy TMT Observatory Corporation. Click to embiggen.
An artist's concept illustration of the Thirty Meter Telescope. Courtesy TMT Observatory Corporation. Click to embiggen.

The Big Island of Hawai’i is getting another telescope to add to its collection of super-observatories high atop Mauna Kea. The Thirty Meter Telescope, or TMT, will be the be the most capable and advanced telescope ever constructed and consist of a 30-meter primary mirror made of 492 segments. This is nine times the collecting area of any telescope known today.  It will use adaptive optics and laser guide stars to correct for the atmospheric aberration, which even on dry climate of Mauna Kea, can still be a problem on occasion.

This behemoth of a telescope will be completed in 2018, pending a lengthy process of approval on the Big Island to make sure that all cultural and political interests are satisfied with the installation, followed by construction and testing.

Before construction can begin on Mauna Kea, the TMT must submit and have approved an application for a Conservation District Use Permit (CDUP) to the Hawaiian Department of Land and Natural Resources. This will be done through the community-based Office of Mauna Kea Management, which oversees the Mauna Kea summit as part of the University of Hawai’i at Hilo.

A broad coalition of scientists, local political leaders, native groups and others have already been working together to ensure the success of the project.  Once the project is up and running, it will enable astronomers to look at some of the faintest and most distant objects in the universe, with a sensitivity to wavelengths of light ranging from the ultraviolet to the mid-infrared.

I’ve been following the progress of the TMT for some time now. A few years back, I worked with the project on their funding proposal for the NSF, and got to know the project pretty well. I remember thinking that there are going to be a lot of really engaged graduate students and their professors that benefit from this telescope, not to mention the public — particularly when the “pretty pictures” start to roll out. Beyond pretty pix, however, the possibilities for doing cutting-edge ground-based science with TMT are just spectacular!

If all goes as planned, TMT will really tackle some tough topics, including a study of the cosmic  “dark ages” — a time in the history of the universe when the first light sources were starting to shine and when the earliest heavy elements were being formed.  The “first-light” objects are tantalizing scientists, who want to know what they were and what caused them to start shining.  Not only will TMT look at this era of cosmic history, but it will work in tandem with the to-be-launched James Webb Space Telescope. Of course, everything in the cosmos after the first stars began to shine is also fair game for TMT, including the formation of galaxies, the natures of black holes, their formation and influence on their environments, and the nature of planet-formation processes are also fair game for the TMT.  Those are the  kinds of topics that astronomers even a few decades ago could only dream about studying.  When TMT comes online, they’ll have another powerful tool to tease out the details of these cosmic processes and objects.

The TMT project has already been through a $77 million design development phase, financed largely by a $50 million donation from the Gordon and Betty Moore Foundation.  Canada has also contributed $22 million. Another $200 million from the Gordon and Betty Moore Foundation is enabling the next steps for construction. Caltech and the University of California each have agreed to raise matching funds of $50 million to bring the construction total to $300 million, and the Canadian partners propose to supply the enclosure, the telescope structure, and the first light adaptive optics.  The result of all this participation and cooperation should be some pretty ground-breaking science!