Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty

Headshot of Emily Lakdawalla

A couple of notes on the Deep Impact images

Posted by Emily Lakdawalla

03-07-2005 12:29 CDT

Topics: Deep Impact

After the press conference I asked Mike A'Hearn a couple of questions about the raw images we're seeing online. First I asked about the way that most of the images seem to be divided into 4 quadrants. Mike told me that each quadrant of the detector is processed through a different amplifier, and each amplifier is a little bit different. When they calibrate the images, this effect is corrected for, and the 4 quadrants will all look like they have the same exposure settings.

Also, I asked him whether all of the images that we were seeing were actually targeted on the comet. He said yes, and then he said "so you're probably going to ask me why the comet is not showing up in some of them." He reminded me that the MRI has many filters, some of them very narrow-band, which means that they only permit a very narrow range of wavelengths of light through to the detector. In specific, he said, they are often using an ultraviolet filter that is specifically designed to look for the OH- radical (that is, the hydroxyl ion, which forms when water molecules are split). He said that when there are outbursts you can see the comet through this filter, but that when the comet is quiet you might not see anything at all. Unfortunately, the website doesn't say which images are taken through which filters.

So, I am guessing that these images, from the Medium Resolution Imager, were all taken through different filters, but I don't know which ones.

See other posts from July 2005


Or read more blog entries about: Deep Impact


Leave a Comment:

You must be logged in to submit a comment. Log in now.
Facebook Twitter Email RSS AddThis

Blog Search


Advocate for Space!

Fifteen years ago, Society members and passionate space advocates like you helped save the Pluto mission. Now we can do the same for missions to Europa and Mars.

Join over 27,600 people who have completed their petition and consider a donation to support advocacy efforts.

Sign Our Petition

Featured Images

Charon in 3D
Space Launch System on the launchpad (artist's concept)
The Magnificent Neptunian System
Pluto's blue skies
More Images

Featured Video

A Perfect, Clear Day: LightSail's Launch

Watch Now

Space in Images

Pretty pictures and
awe-inspiring science.

See More

Selfies to Space!

Take flight with a selfie on LightSail™ in 2016!

Send a Selfie Now

Connect With Us

Facebook! Twitter! Google+ and more…
Continue the conversation with our online community!