3D image of Mercury using MDIS data from the MESSENGER space probe and mapping it onto a sphere in Daz3D Bryce.

My second semester astronomy class during the 2014-15 school year at Walden School of Liberal Arts focused on planetary science. Our trip to the American Astronomical Society conference in early January had been the final project of our first semester class, which had focused on astrophysics. I wanted a comparable project that involved analyzing planetary data for the second semester.

3D image of Mercury using MESSENGER data. The bright spot is the Rachmaninoff region of Mercury.

I had heard of a program called MESSENGER Student Planetary Investigators, where teams of students in schools could collaborate with scientists on the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) space probe orbiting Mercury to download data and images. I applied for it during the fall and we were accepted.

Large double-ringed impact basins on Mercury. The distinct crater at the north has rays that cover much of Mercury’s surface, but they are much more obvious in our enhanced color images (see below).

We held a series of monthly webcasts with scientists on the MESSENGER team. The probe was the first to visit Mercury since the three flybys of Mariner 10 in 1975. Launched on August 3, 2004, it took a looping path past Venus, twice past Earth, and three times past Mercury to gradually slow down its orbit around the Sun to where Mercury could capture it into orbit. It went into orbit on March 18, 2011 and collected data for four years before running out of navigation propellant. It was deliberately de-orbited (NASA-speak for “crashed”) into the surface of Mercury on April 30, 2015, which was during the time we were studying it.

Here is the same crater in enhanced color. The bluish-lavender lines are rays ejected from the impact. They are more visible in the 430 nm MDIS image, here mapped to the blue channel in Adobe Photoshop.

Our first webinar was with Dr. Nancy Chabot, who taught the students about the mission and the various on-board instruments, including the Mercury Dual Imaging System (MDIS) and the Mercury Laser Altimeter (MLA). The MDIS could image the surface using filters in ten wavelengths, and we learned where and how to access the data in what was called Quickmaps and choose which wavelengths to download. Each image was over one gigabyte in size, and stretched the memory of our Macintosh laptops to the limit. Because of Mercury’s slow rotation, the images show high Sun elevation in some areas and lower angles in others, and quite a bit of adjustment has been made to patch the mosaics together. The MLA 3D data of the surface was only available for the northern hemisphere, because of the highly elliptical nature of MESSENGER’s orbit.

More rays ejected onto the Mercury surface by impacts. Some of these impacts have rays that cover much of the surface. In this enhanced color image, impact features are blue-lavender and volcanic features are yellow-orange (higher sulfur).

We started by taking one of the MDIS images in visible wavelengths and used it as a texture map on a sphere in our 3D software to create an animation of Mercury rotating. This was remarkable in itself as only 40% of the surface had ever been mapped before MESSENGER.

A large double-ringed impact basin on Mercury. In this enhanced color image, yellow-orange areas indicate volcanic features. This crater was filled by a basaltic eruption.

Using the same technique we had learned for the WISE mission, we picked three of the MDIS images (including some infrared) and put them into the RGB channels in Adobe Photoshop. Different students used different images, but whichever one was the shortest wavelength, we put into the blue channel. The middle wavelength went into the green channel, and the longest (usually infrared, such as 1000 nanometers) went into the red channel. The result wasn’t terribly exciting at first, because it showed basically the same boring gray color that Mercury appears in normal visible light. But I had the students push the contrast and saturation of the colors to the maximum, and interesting things began to happen.

In this enhanced color image, the crater with the yellow bottom shows hollows and pits that are fairly recent and show that Mercury’s surface is still evolving. The blue-lavender lines are ejected rays from a crater to the north.

One student, Elena Mitchell (who had also gone to Seattle for the AAS), decided she wanted to pursue this research further as a science fair research project. She chose the three images that were furthest apart: 430 nm (violet), 730 nm (far red), and 100 nm (infrared) and combined them into the blue, green, and red channels in Photoshop. She then stretched the saturation and color contrast and came up with images that showed different colors for impact features (lavender, we think because of higher levels of magnesium sulfate) and volcanic features (yellow-orange, because of more sulfur). She had picked the wavelengths specifically to show up sulfur. She chose several areas of particular interest and learned their names. All Mercury features are being named after famous artists, such as the Rachmaninoff Basin. Her images showed yellow-orange pits in the Lermontov region called hollows that are fairly recent and show that the surface of Mercury is still evolving. Large double-ringed craters showed different shades of orange to red, indicating different basaltic eruptions. Large lavender rays covering much of the surface radiate out from impact basins such as Caloris Basin.

The brightest area on Mercury is this region northeast of Rachmaninoff Basin. In this enhanced color image, it is clearly showing recent volcanism. The basin itself shows a double ring with different chemical compositions in each ring – more sulfur-based materials in the center (possibly from the volcanic center to the southeast), more magnesium in the outer ring (if our analysis is correct). You can also see how piecing the mosaics together led to some calibration issues when we enhanced the color.

She worked very hard to understand what the colors indicated, looking at other instruments that got data on the surface composition. She also found the MLA data for the northern hemisphere and created 3D models, although they are not as detailed as the ones we’ve done for Mars and the Moon. She tried to match up the 3D models with Lermontov and other areas that showed interesting features. She even built a paper 3D model of the MESSENGER probe.

Lermantov Crater shows pits and hollows inside that appear to be associated with recent volcanic activity. Of course, on Mercury, “recent” could mean a billion years.

She was the only student from Walden School that did a science fair project, and she was able to advance from the Charter District fair in February to the regional Central Utah Science and Engineering Fair in March. I was very pleased when her project was announced as one of the Sweepstakes winners, which meant she would be going on to the International Science and Engineering Fair in Pittsburg in May. This has been a bucket list item of mine, to help a student go all the way with a science fair project. She also won a full-ride scholarship to Westminster College.

A view toward the north pole of Mercury using enhanced MDIS images of 430, 630, and 1000 nm mapped into the RGB channels in Adobe Photoshop and enhanced (added contrast and color saturation). You can see ghost craters where lava flows have filled in the crater but left slight impressions behind.

In between all of this, she was selected as our school’s Science Sterling Scholar, a competition for high school students in 13 categories, where one student for each category is chosen from a school. They complete a portfolio, write essays, and interview for the position. Elena made it past the regional interview and was one of the 15 finalists for the entire state of Utah.

Elena’s science fair project. She explains the process she used to combine three wavelengths into the RGB channels of Adobe Photoshop to make our enhanced color images. She also took MLA data to make 3D models, and built a paper model of MESSENGER (below left).

She spent five days in Pittsburg for ISEF, and it was an amazing experience for her. She won a geology association award, and is now studying Geological Engineering at the University of Utah. It just goes to show how important it is for students to get their hands on real data and do their own original science. It can engage and inspire them and show them that science is not just for nerds and brainiacs. Anyone can become a scientist, if they’re motivated enough. Elena was always one of my best students, but she hadn’t really considered geology as a career until she did this Mercury data project. Between using the MESSENGER data, traveling to AAS, and being part of NITARP, a new world of possibilities opened up.

This is why I am a teacher.

Elena with her science fair project. She won a Sweepstakes Award at the Central Utah Science and Engineering Fair (CUSEF) and traveled to the International Science and Engineering Fair in Pittsburg in May, 2015.