A New Look at a Hot, Magnetic Personality: UBC Geophysicist Part of NASA Mercury Mission

A University of British Columbia geophysicist is part of a NASA mission that is unveiling the first images of Mercury taken from the planet’s orbit, and capturing new data on the tiny planet’s crust, topography and geologic history.

UBC’s Catherine Johnson, an expert in planetary magnetic and gravity fields, is part of NASA’s MESSENGER Mission’s geophysics group. Johnson, along with along with colleagues at Goddard Space Flight Lab and the Applied Physics Lab, is analyzing the initial data collected by the spacecraft’s magnetometer, which has measured Mercury’s magnetic field during 10 passes near the planet since the instrument was turned on March 23.

“A team of scientists is working away on analyzing the data from MESSENGER’s various instruments, all of which are now on and returning data,” says Johnson. “My group at UBC is working with the magnetic field, altimetry, and radio science data to try to understand the structure of Mercury’s internally generated field and how it interacts with solar wind.”

The spacecraft delivered its first photo of the planet early yesterday morning, after entering Mercury’s orbit on March 17. MESSENGER is now in its orbital commissioning phase, during which its instruments are turned on and tested.

MESSENGER’s primary mission is to collect data on the composition and structure of Mercury’s crust, topography and geologic history, thin atmosphere and active magnetosphere, and makeup of core and polar materials.

“Over the next few weeks, the focus will be on collecting results from the early data as well as getting set up for a year of data collection and analysis,” says Johnson. “From what we’ve seen so far, it’s a very dynamic environment.”

Mercury, the solar system’s smallest and densest planet, is one of only four terrestrial planets in the inner solar system, and in many ways is the most extreme, says Johnson.

“Due to Mercury’s proximity to the Sun, daily temperature variations are in the hundreds of degrees near the equator. Solar wind interacts with the magnetic field and the planet’s surface. We want to know how this affects its environment.”

“Understanding Mercury is crucial to understanding the family of inner solar system planets. The MESSENGER data will help us better understand our own planet.”

The images are the first to be obtained from a spacecraft in orbit around the solar system’s innermost planet. Over 360 photos were taken during the initial six hour period. Those images are being returned to Earth, where MESSENGER scientists are reviewing the data.

“The first images from orbit and the first measurements from MESSENGER’s other payload instruments are only the opening trickle of the flood of new information that we can expect over the coming year.” says MESSENGER Principal Investigator Sean Solomon, of the Carnegie Institution of Washington.

By the time MESSENGER completes its year-long survey of Mercury, over 75,000 images will be returned to Earth.